allergy, stress and sense of coherence in families with...
TRANSCRIPT
ACTAUNIVERSITATIS
UPSALIENSISUPPSALA
2014
Digital Comprehensive Summaries of Uppsala Dissertationsfrom the Faculty of Medicine 992
Allergy, Stress and Sense ofCoherence in Families withChildren living in accordance withan Anthroposophic Lifestyle
JACKIE SWARTZ
ISSN 1651-6206ISBN 978-91-554-8934-2urn:nbn:se:uu:diva-221438
Dissertation presented at Uppsala University to be publicly examined in Universitetshuset,sal IX, S:t Olofsgatan, Uppsala, Thursday, 22 May 2014 at 13:00 for the degree of Doctorof Philosophy. The examination will be conducted in Swedish. Faculty examiner: Assistentprofessor Gösta Alfvén (Karolinska Institutet).
AbstractSwartz, J. 2014. Allergy, Stress and Sense of Coherence in Families with Children livingin accordance with an Anthroposophic Lifestyle. Digital Comprehensive Summaries ofUppsala Dissertations from the Faculty of Medicine 992. 58 pp. Uppsala: Acta UniversitatisUpsaliensis. ISBN 978-91-554-8934-2.
Background: Previous studies on anthroposophic lifestyle and allergy show that the childrenhave less risk of developing allergies. All studies so far have been retrospective and haveincluded children in school age. In view of the facts that this lifestyle seems to protect childrenfrom allergies and that different symptoms of atopy have increased dramatically during the lastdecades it is of general interest to study this group of children more in detail. The earlier findingshave now been followed up in a prospective research program ALADDIN (Assessment of Lifestyle and Allergic Disease During Infancy), applying different approaches. One of these is tofocus on stress (as measured by cortisol) as a factor that may underlie the decreased risk ofallergy in children from anthroposophic families.
Aim: This thesis is based on data from the ALADDIN study focusing on influence of familylifestyle on allergy sensitization early in children’s life in relation to psychosocial factors andsalivary cortisol as an indicator of stress.
Methods: A total of 552 families were recruited during pregnancy or during the first month ofthe child´s life in two recruitment waves, 330 families between September 2004 and November2007 and another 222 families between March 2008 and January 2011. They were recruitedat anthroposophic maternal and child health care centers (MCHC) and from conventionalMCHCs. Data on demographics and exposures were obtained by questionnaires and interviews.Parental capacity to adapt to stressors was evaluated by means of the questionnaire “Sense ofCoherence” (SOC; Antonovsky). Salivary samples were collected at home from the infants andboth parents for analyzes of cortisol. Blood samples were obtained from the parents and fromthe children for analyzes of IgE.
Results: Many family related characteristics differed markedly between the groups beforeand during pregnancy, during delivery and the first 12 months of age. Children fromanthroposophic families had lower levels of salivary cortisol compared to peers from familieswith a more conventional lifestyle on all sampling occasions at 6 months of age and on someof the occasions at 12 and 24 months of age. There were no differences concerning cortisolbetween parents with different lifestyle and no significant differences concerning SOC-scoresbetween the three lifestyle groups. An anthroposophic lifestyle was associated with a lowerrisk of allergic sensitization up to five years of age. This risk was partially explained by lowercortisol levels during infancy. Children in families with a partly anthroposophic lifestyle alsohad substantially lower risk of sensitization.
Conclusion: An anthroposophic lifestyle protects from development of allergy duringchildhood, at least up to five years of age. This protective capacity is partly mediated by lowcortisol levels during infancy but is also dependent on unknown characteristics of this lifestyle. These results call for further studies on health related effects of an anthroposophic lifestyle.
Keywords: Anthroposophic lifestyle, Allergy, Stress, Children, Sense of Coherence
Jackie Swartz, Department of Neuroscience, Box 593, Uppsala University, SE-75124Uppsala, Sweden.
© Jackie Swartz 2014
ISSN 1651-6206ISBN 978-91-554-8934-2urn:nbn:se:uu:diva-221438 (http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-221438)
LIST OF PUBLICATIONS
1. Stenius F, Swartz J, Lindblad F, Pershagen G, Scheynius A, Alm J, Theorell T. Low salivary cortisol levels in infants of families with an anthroposophic lifestyle. Psychoneuroendo-crinology. 2010 Nov; 35(10):1431-7.
2. Swartz J, Stenius F, Alm J, Theorell T, Lindblad F. Life
style and salivary cortisol at the age of 12 and 24 months. Acta Paediatr. 2012 ;101(9):979-84.
3. Swartz J, Alm J, Theorell T, Lindblad F. Parental Sense of
Coherence in the first 2 years of life is not related to parental and child diurnal cortisol rhythm or proxies of anthroposoph-ic lifestyle. Acta Paediatr 2013;102(9):920-4.
4. Swartz J, Lindblad F, Arinell H, Theorell T, Alm J. An-
throposophic lifestyle and salivary cortisol predict sensitiza-tion during childhood – The ALADDIN cohort. In manu-script.
To all parents who are seeking to help their children to develop according to Convention on the Rights of the Child Article 27 1. States Parties recognize the right of every child to a standard of living adequate for the child's physical, mental, spiritual, moral and social development.
CONTENTS
1 INTRODUCTION .............................................................................. 7 2 BACKGROUND ............................................................................. 10 2.1 Anthroposophic lifestyle ............................................................... 10 2.2 Allergy .......................................................................................... 11 2.2.1 Prevalence and clinical characteristics ...................................... 11 2.2.2 The hygiene hypothesis ............................................................. 13 2.2.3 Dietary factors ........................................................................... 14 2.2.4 Growing up at a farm with animals ........................................... 15 2.3 Stress and salivary cortisol ........................................................... 15 2.4 Ability to adapt to stressors – Sense of Coherence ...................... 18 2.5 Salivary cortisol and allergy ......................................................... 18 3 AIMS ............................................................................................... 21 4 SUBJECTS AND METHODS ........................................................ 22
4.1 Study population ........................................................................... 22 4.2 Study design .................................................................................. 23 4.3 Salivary cortisol ............................................................................. 25 4.4 Blood samples, sensitization data .................................................. 25 4.5 Sense of Coherence ....................................................................... 26 4.6 Statistical analyzes and ethics ....................................................... 26
5 RESULTS ........................................................................................ 29 5.1 Exposure characteristics in the lifestyle groups ............................ 29 5.2 Salivary cortisol levels in children at age 6 months and their parents and the relation to lifestyle. ..................................................... 34 5.3 Salivary cortisol levels in children at 12 and 24 months of age and in their parents and the relation to lifestyle. ........................... 34 5.4 Parental Sense of Coherence in relation to parental and child cortisol levels as well as to lifestyle .................................................... 36 5.5 The relations between lifestyle group and sensitization in children up to age 60 months, also taking cortisol levels at age 6 months into account. ............................................................................ 36
6 INTEGRATIVE DISCUSSION ...................................................... 38 7 CONCLUSION ............................................................................... 41 8 SVENSK SAMMANFATTNING ................................................... 42 9 ACKNOWLEDGMENTS ............................................................... 44 10 REFERENCES ............................................................................. 46
LIST OF ABBREVATIONS ALADDIN Assessment of Lifestyle and Allergic Disease During
Infancy;
HPA Hypothalamic-pituitary-adrenal
OR Odds ratio
SOC Sense of Coherence
MCHC Maternal and child health care centers
IgE Immunoglobulin E
kUa/L Kilo units of allergens per liter
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1 INTRODUCTION In contrast to the increasing incidence of allergy in children it seemed as if children in Steiner schools had a lower prevalence of allergic diseases than expected during the mid-90´s. Emanating from this personal observation a contact was established with a project group at Karolinska Institutet studying possible explanations of al-lergy in infants. In the first – cross-sectional – study from the col-laboration to follow, 295 children aged 5-13 years from two Steiner schools in Järna and 380 children of the same ages from two munic-ipal schools in the same area participated (1) Children from Steiner schools had a lower prevalence of allergy, both by clinical and by serological or skin-prick test (1). This study was followed by a large European multicentre study, PARSIFAL, with the same model as the national one, where the results were confirmed (2). None of the previous studies on anthroposophic lifestyle, which had been focused on the physical environment like different kinds of diets, material of clothes, vaccination etc. had found any separate characteristic that was able to explain the decreased risk of child-hood allergy. Results from other studies indicating a relation be-tween psychosocial factors during pregnancy or early life and aller-gic diseases (3) gave an impulse to search for psychosocial qualities of the anthroposophic lifestyle with a special focus on stress related issues. All earlier studies on health aspects of an anthroposophic lifestyle had been retrospective but in order to find causal explana-tions, prospective studies are needed. Since 2004, an on-going pro-ject, ALADDIN (Assessment of Life style and Allergic Disease Dur-ing Infancy), is collecting information from a cohort group, which implies better prospects of examining the connection between life-style, allergy, psychosocial environment and underlying immunolog-ical mechanisms. This thesis is based on data from the ALADDIN study focusing on influence of family lifestyle on allergy sensitiza-tions early in children’s life in relation to psychosocial factors and salivary cortisol as an indicator of stress.
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2 BACKGROUND 2.1 Anthroposophic lifestyle The philosopher and scientist Rudolf Steiner (1861-1925) developed Anthroposophy as a «science of the spirit.» The word “anthroposo-phy” means “wisdom of the human being,” or the awareness of one’s humanity – in line with the demands described in Convention on the Rights of the Child. Anthroposophy has inspired people around the world to look at life in a wider perspective. Over time, about 10,000 institutions and initiatives around the world have been founded that endeavor to apply anthroposophy: schools (often called Rudolf Steiner schools, Waldorf schools or independent schools), and schools work-ing within therapeutic education and sociotherapy, medical units, pharmaceutical companies, biodynamic farms, banks, art schools, stage groups, etc. The anthroposophic movement has its world centre at Goetheanum, Dornach in Switzerland. In Sweden anthroposophy has its centre in Järna, situated about 50 kilometers south of Stock-holm with, inter alia, biodynamic farming, Rudolf Steiner schools, a medical clinic, a mother and child health care centre, several institu-tions for psychiatric treatment and/or or psychosocial training, bank-ing and a culture centre with performances by artists from all around the world. Most children in Steiner schools grow up in families with a view of life inspired from anthroposophy, which constitutes a lifestyle with many characteristics different from a more conventional one. Among other things many children are born at home, they eat more biodynam-ic/organic vegetables and fermented vegetables with unpasteurized lacto bacteria, use less antibiotics and antipyretics and their parents are more restrictive regarding child vaccination (4). Furthermore the infants are protected from technical equipments including strong light and sound with the intention to reduce stressful stimuli from the envi-ronment early in life, starting already during pregnancy. The body is kept warm with clothes made by wool or silk worn day and night from head to feet, indoor as well as outdoors. The skin is stimulated not only by close body contact with use of a baby sling but also by appli-cation of etheric oils almost every day. Already from pregnancy par-ents try to find a rhythm in the day, which will be emphasized after the birth for both mother and child. The rhythm becomes as a “hous-ing” where the child can feel safe and come to rest (4)). This lifestyle
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also includes more complex phenomena like a holistic view of life including spiritual values. To the latter belong thoughts about karma and reincarnation, which, inter alia, means that the child returns to the earth from a spiritual world and comes with properties to be devel-oped further. The child has chosen its parents, who provide the best conditions for the child's start in life. 2.2 Allergy 2.2.1 Prevalence and clinical characteristics A steady increase in the prevalence of allergic diseases has occurred globally during the last decades with about 30-40% of the world popu-lation now being affected by one or more allergic conditions. A high proportion of this increase occurs in children and it looks like the de-veloping world may soon resemble that of wealthier nations (5). Even if the prevalence of allergy is high during childhood some aller-gic symptoms fade away over time. For example cow’s milk allergy can develop during the neonatal period or the first year of life and then remit during childhood. Tolerance develops in half of the cases within two years after the diagnosis has been established and 80% of patients develop tolerance within 3–4 years (6)The prevalence of cow’s milk protein allergy varies from a few percent up to 7.5 percent (6-9)On the other hand, specific IgE antibodies towards cow’s milk and egg white indicate an early beginning of an atopic predisposition which may be-come manifest even during later childhood as either allergic rhinitis or allergic asthma (10) Since reactions to environmental exposures could be mediated by various mechanisms there is a need for a uniform terminology. An international collective nomenclature has been proposed by the World Allergy Organization and revised 2004 (11). When symptoms appear after exposure to a substance at a dose usually tolerated by a healthy person it is called a hypersensitive reaction. If the hypersensitive re-action is mediated by specific immunologic mechanisms, such as IgE-antibodies or T-cells (12, 13) it is called allergic hypersensitivity. If other mechanisms are involved, the term non-allergic hypersensitivi-ty, or intolerance, should be used. Allergic hypersensitivity (allergy) is classified either as IgE-mediated or non-IgE-mediated. The latter is mediated by other types of antibodies than IgE or cell-mediated. The
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term atopy describes a personal and/or familial tendency to develop sensitization and produce IgE-antibodies – typically verified by blood analysis or a positive skin prick test – in response to common envi-ronmental substances that usually do not induce such reactions in healthy individuals. The allergy related immune response starts with sensitization and is expressed as an elevated allergen specific IgE level, commonly > 0.35 kU/L (14). Sensitization to environmental allergens is some-times observed during the first month of life and may or may not be linked to allergic symptoms (10, 15). Mostly there is a strong associ-ation between sensitization and clinical symptoms (12, 16) but an individual can be sensitized without having symptoms. The level of allergen specific IgE is related to the risk of developing allergic symptoms (14) The expressions of allergic diseases usually vary with age, and symp-toms can disappear and be replaced by other symptoms in the so-called atopic march (17, 18), see Figure 1. During infancy the main allergy related symptom is atopic eczema, followed by gastrointestinal symptoms and recurrent wheezing, whereas allergic rhino-conjunctivitis is a main problem later in childhood (19). Sensitization to milk and egg mostly occurs during the first 2–3 years of life, while sensitization to inhalant allergens occurs later in childhood with in-creasing prevalence during the first years of school age (8–10). Sensi-tization to indoor airborne allergens as house dust mites and pets often occurs at a lower age than sensitization to pollens (birch and grass) (5).
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Figure 1. The allergic march. A large variety of risk factors for allergy have been described includ-ing exposure to air pollution and parental smoking (20). However, the review to follow will focus on three types of risk factors that may be of particular relevance for children growing up in anthroposophic families, the hygiene hypothesis, dietary factors and growing up at a farm with animals. The risk that has been attributed to exposure to stressors will be described below in a separate paragraph in relation to the presentation of the concept of stress. 2.2.2. The hygiene hypothesis The hygiene hypothesis was originally formulated in 1989 by the epi-demiologist David Strachan who reported findings of an inverse rela-tionship between family size and the development of atopic disorders. This hypothesis suggests that lower incidence of infections during early childhood could be an explanation for the rapid rise in allergic diseases such as asthma and hay fever (21, 22). There is some indica-tion in that direction from studies where infections have been linked to reduce prevalence of IgE sensitization like hepatitis A, Toxoplasma gondii and Helicobacter pylori (23). Vaccinations cause immunostim-ulation that may have a favorable effect to protect against allergy. Al-ternatively they may prevent “protective” infections and thus have an unfavorable effect (24). An allergy protective effect by measles has been indicated (25, 26) however also an opposite association (27). Along the same line day care attendance in early life, implying
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high exposure to infections is in some studies associated with a re-duced risk of asthma and recurrent wheezing (28-30) while in others early infections do not seem to protect against allergic diseases (31). The treatment of infections with antibiotics and antipyretics may in-crease susceptibility to allergy. Administration of antibiotics during early life was associated with a higher prevalence of allergic disease (32-34). 2.2.3 Dietary factors Exclusive breastfeeding for six months may have a protective effect, no effect, or even a predisposing effect. For infants with a documented hereditary risk of allergy (i.e., an affected parent and/or sibling) who cannot be breastfed exclusively, dietary products with confirmed re-duced allergenicity are recommended (35). Findings are not conclu-sive about the question if early introduction of potentially allergenic foods increases or decreases the risk of future allergy (36). The timing of n-3 long-chain polyunsaturated fatty acid supplementation may play a role in preventing early childhood allergy. Several supplements diets have been suggested to be protective – like vitamins A, D, and E; zinc; fruit and vegetables; a Mediterranean diet – but the exact timing of introduction of complementary food is still under discussion, and the strength of associations diverge (35, 37-39). Low total diversity of the gut microbiota during the first month of life is associated with asthma (40). Also less food diversity during the first year of life seems to be a risk factor for allergy development (41). An enhanced microbial diversity during early life may be of crucial im-portance for preventing of eczema in high-risk infants (42). Early gut micro flora of children who later develop atopic ezcema has more Staphylococcus aureus and coli-forms and less lactobacilli and bifido bacteria (43, 44). This could be in line with findings that early-life ex-posure to unpasteurized milk may protect against atopy, asthma, and related conditions, independently of place of residence and farming status, and in both children and adults (45). The consumption of un-processed cow’s milk significantly decreased allergic sensitization, clinically expressed as asthma or hay fever (46). The ‘raw milk effect’ was seen not only for inhalant allergens, but also for food allergens (46). Notably no significant association was observed once the raw milk was boiled (47).
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2.2.4 Growing up at a farm with animals Numerous population-based studies have shown that the risk of devel-oping childhood asthma, hay fever, and allergic sensitization to both food and inhalant allergens is significantly reduced in children grow-ing up in farming environments (48, 49). For IgE sensitization, these included contact with dogs, poultry, horses, straw, hay and grain farm activities (50, 51). Direct contact with farm animals reduces atopic eczema risk in early life in some settings, especially where mothers have regular contact with farm animals during pregnancy, and this protective effect appears to be even stronger in those who are exposed both pre- and postnatal (52, 53). The risk of atopic eczema developing in the first year of life was reduced by more than half amongst chil-dren whose mothers had contact with three or more farm animal spe-cies during pregnancy compared to children of mothers without con-tact (52). New strategies for primary prevention of allergy aims to facilitate exposure to protecting factors, which promote the induction of immunologic tolerance against innocuous antigens. These factors are associated among others with farming environment and a ‘tradi-tional lifestyle’, where one example from the authors is the anthropo-sophic lifestyle (36). 2.3 Stress and salivary cortisol Hans Selye, the father of the stress concept, conceptualized stress as the General Adaptation Syndrome (GAS). Based on experimental an-imal studies, Selye postulated that exposure to stressors is followed by a generalized response consisting of three stages 1) Alarm stage 2) Adaptation stage 3) Exhaustion stage (54). Today, cognitive aspects of the stress reaction are often more strongly emphasized, as in the Cog-nitive Activation Theory of Stress (CATS) (55). The main compo-nents in CATS are the stimuli (stressor), the subjective reports of an experience, a general non-specific increase in arousal and then feed-back to the brain from the result of the response. Whether a stimulus is considered exciting or threatening depends on previous experiences and expectations of the outcome (55). This means that the process is dynamic; the stressor and outcome are evaluated and reevaluated in similar future situations. Thus, according to CATS, there is no point in trying to measure stress by objectively focusing on the external load of exposure. Attempts to measure stress should be focused on the sub-jective experience and feelings induced by the stressors and the stress
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response (55). During infancy and preschool age, measuring cortisol levels is commonly applied as a method for capturing “stress”. In accordance with the more dynamic way to think about stress the concept of allostasis was developed. The term allostasis literally means, “to stand in variability,” emphasizing stability through change in contrast to the concept of homeostasis, meaning, ”to stand equally”. More important for maintaining health is the ability to respond and cause an appropriate arousal when facing an environmental challenge. In the allostatic model, health is defined as a state of responsiveness, including also the ability to come to rest. Allostatic overload can have a negative influence on endocrine, metabolic and immunological sys-tem and if allostatic load is chronically high, then pathologies develop (56, 57). Cortisol levels follow a diurnal variation with high levels at awaken-ing, a further increase during the morning and a gradual decrease over the day until midnight (58). This diurnal rhythm seems to be estab-lished already during the first months of life but a delay up to nine months of age has been reported (59). Genetic factors seem to influ-ence cortisol levels, especially levels in the morning (60-62) where heredity is estimated to 40-60% (61). The heritability in a twin study was estimated to 31% for the morning level (30 minutes after awaken-ing) but 0% for the evening level; shared environment accounted for 71% of the evening level (63). For children the easiest way to measure cortisol is to collect saliva. Saliva levels are highly correlated with cortisol levels in serum (64)). There are different ways of measuring and evaluating the levels and dynamics of cortisol and this may influ-ence and explain the many different results coming up. The main types of measurements can be divided into four groups: 1) Single time points, including means (or sums) of several single measurements 2) Deviations/slopes between two or more measurements 3) Area under the curve (AUC) calculated from two or more measurements, and 4) Effects of a dexamethasone test (Margareta Kristenson, Peter Garvin and Ulf Lundberg. The Role of Saliva Cortisol Measurement in Health and Disease, 2012, 3-16). When the individual perceives stress there is an imbalance between demands from the psychosocial environment and the ability to cope with it. This situation may activate the HPA-axis (Hypothalamus-Pituitary-Adrenal cortex) where Corticotrophin-Releasing Hormone
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(CRH) produced in hypothalamus increases and induces increased secretion of Adrenocorticotropic Hormone (ACTH) from the pituitary gland. ACTH then stimulates the cortex of the adrenal glands to se-crete cortisol into the circulation. In contrast to stress hormones such as adrenaline and noradrenaline, which rapidly enter the bloodstream after exposure to a stressful situation, the secretion of cortisol is gen-erally slower and peaks typically after 20-30 min (65). Feedback loops are present at a number of levels in order to modulate responsiveness of the HPA axis and return the system to homeostasis since chronical-ly elevated cortisol levels can have deleterious effects on health (66, 67). Chronic stress can blunt the HPA-axis, down-regulate the expres-sion of glucocorticoid receptors (GRs), and decrease morning cortisol levels (68). Cortisol has a central role in affecting several physiological processes like mobilizing energy stores, elevating blood pressure and inhibiting immunologicaland inflammatory processes (66). There is some evi-dence that the functioning of the HPA-axis is influenced by early ex-periences (69, 70). Some studies have suggested that this shaping of the axis starts already during the prenatal period (71-73). After birth environmental factors continue to influence the regulation of the HPA-axis. Several studies have shown that toddlers with a secure at-tachment do not exhibit elevations in cortisol, while those with an insecure relationship to their parent are much more likely to show in-creases (74-80). Exposure to early childhood adversity seems to be associated mainly to HPA hyper-functioning although different kinds of exposure to maltreatment seem to be correlated with different cortisol regulation patterns (81). They may be expressed as elevated baseline cortisol levels (82) higher levels of awakening cortisol (83) or increased reac-tivity at exposure to stressors (84)and low morning cortisol levels with blunted diurnal cortisol patterns (85). Cortisol reactivity appears to decrease with age. Accordingly, acute stressors like weighing, exam-ining, bathing, heel-sticking and vaccination provoke a small to mod-erate cortisol reaction in infants younger than six months but mostly smaller reaction in infants older than 6 months. Most studies after this age have investigated changes in cortisol reactivity more in response to psychological stressors like mother–infant separations. With in-creasing age children develop new behavioral skills that facilitate ad-aptation and experimental stressors do not necessarily provoke activa-
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tion of the HPA-axis as previously, during infancy. The way children seek to control the stress reaction has not yet been given sufficient attention and there is a need for more study of infant regulative pro-cesses to better understand infant development (86). 2.4 Ability to adapt to stressors - Sense of Coherence In non-human primates, the presence of the mother provides a power-ful buffering factor, reducing elevations in cortisol to stressors like capture, handling, and separation (87). Neither anger nor fearfulness predicts increases in the cortisol levels of a child in the presence of an adult who is sensitive and responsive (77, 88). Parental capacity to cope with stressors is probably a concept that is close to such parental qualities. A common way to scientifically evaluate this capacity is through the questionnaire Sense of Coherence (SOC), which was de-veloped by Aaron Antonovsky (89). High SOC scores reflect abilities to define life events as less stressful (comprehensibility) and mobilize resources to deal with encountered stressors (manageability). They also reflect motivation, desire, and commitment to cope (meaningful-ness) (89). Antonovsky hypothesized that ”SOC has direct physiologi-cal consequences”, meaning that endocrine and immunologic process-es may be affected (89). Only few studies have investigated this hy-pothesis in relation to the HPA-axis. In a study of maternal serum cor-tisol levels before and after childbirth, there was a negative association between scores on the SOC-subscale of comprehensibility and postnatal cortisol levels (90). In another study, with a focus on IBD (Inflammatory Bowel Disease) in adults, there were significantly higher serum cortisol levels in individuals with low SOC scores in the rather small (n=21) control group but not in the larger (n=78) study group (91). In a study about cardiovascular disease SOC was positive-ly associated with religiosity/spirituality and highly religious partici-pants presented lower serum cortisol levels (92). In abused adoles-cents SOC was consistently related to lower cortisol in the morning (93). Men with good self rated health (SRH) had higher scores of SOC and better saliva cortisol regulation and lower levels of baseline corti-sol (94). 2.5 Salivary cortisol and allergy The onset and further development of childhood allergy can be acti-vated by a hypo-responsive as well as a hyper-responsive HPA axis
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(95). Atopic disposition in early infancy seems to be associated with hyper-responsiveness of the HPA axis to stress (96, 97). Stenius et al. found a clear association between raised levels of cortisol at age 6 months and risk for sensitization and eczema during the first 2 years of life (98). Along the same line, infants predisposed to allergic dis-ease had higher levels of cortisol prior to the onset of disease (96, 97). Some types of perceived maternal stress are associated with raised blood cortisol levels, and about 10-20% of the cortisol can pass the human placenta (99) with increased fetal cortisol levels as a conse-quence. These elevated levels may hypothetically have a program-ming effect on the HPA axis, leading to altered stress responses after birth (100). Many studies have demonstrated an association between maternal exposure to stressors during pregnancy and later develop-ment of allergic disease in children (99-102). A study by Peters et al. reported an association between prenatal maternal stress and increase d cord blood total IgE in infants (103). Several studies report influence of postnatal stress on the child. As reviewed by Chida et al, various postnatal psychosocial factors like caregiver stress, maternal psychiatric disorder and family conflict may increase the risk of atopic disorders and may also influence the prog-nosis of such disorders (3). For example, exposure to maternal depres-sion and anxiety from birth and up to age 7 years demonstrated an association with childhood asthma (104). Parental stress – one year before medical investigation – assessed with a questionnaire on whether respondents perceived their lives as unpredictable, uncontrol-lable or overwhelming was associated to the risk of childhood wheeze among children with no previous asthma or parental history of asthma, especially among boys (105). In a study with a clinical outcome, ma-ternal symptoms of anxiety at 18 and 32 weeks of gestation increased the risk of asthma at age 7 ½ years (100). Both allergic eczema and allergic asthma have been associated to en-vironments with high levels of emotional stress induced by divorce, moving or parenting difficulties (106, 107). Children with allergic eczema showed significantly attenuated cortisol levels in response to a standardized psychological stressor (Trier Social Stress Test [TSST-C]), when compared to a non-atopic control group (108). Wolf et al. reported that chronic stress and low socioeconomic status were linked to elevated cortisol levels in healthy but not in allergic asthma chil-
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dren, observation that may point to a lower HPA-axis responsiveness to chronic home stress in allergic children (109).
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3 AIMS This thesis is based on data from the ALADDIN-study focusing on influence of family lifestyle on allergy sensitizations early in chil-dren’s life in relation to psychosocial factors and salivary cortisol as an indicator of stress. The specific aims are: Paper I To investigate if infants in families with an anthroposophic lifestyle have different levels of salivary cortisol than other children Paper II 1. To investigate salivary cortisol levels over the day in 12- and 24-month-olds and their parents, comparing outcomes with regard to an-throposophic or conventional lifestyle 2. To study how the cortisol levels develop over time (between ages of 6, 12 and 24 months). 3. To investigate whether any significantly different cortisol outcomes in the anthroposophic children can be explained by the factors studied in the present research design Paper III 1. To study if SOC-scores vary between groups of parents of infants with three different lifestyles (anthroposophic, partly anthroposophic and non-anthroposophic) 2. To study if parental SOC-scores are related to the diurnal cortisol levels of the parents themselves and to the levels of their infants at the ages of 6, 12 and 24 months Paper IV To investigate the development of sensitization up to age 60 months in children growing up in anthroposophic families, also taking cortisol levels at age 6 months into account
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4 SUBJECTS AND METHODS 4.1 Study population
A total of 552 families were recruited during pregnancy between Sep-tember 2004 and January 2011 in two recruitment waves, 330 families between September 2004 and November 2007 and another 222 fami-lies between March 2008 and January 2011. Most lived in Järna a countryside village 50 km south of Stockholm with a large community of anthroposophic followers. Families were recruited at anthroposoph-ic maternal and child health care centers (MCHC) in Järna and Stock-holm (n = 312) and from conventional MCHCs in Järna and the nearby town Södertälje (n = 240). Finally 507 families decided to participate. Infants born before gestational week 36 and miscarriages were exclud-ed from the study. The flow of participants and loss at follow-ups is shown in figure 2.
Figure 2. Flow chart of the recruitment process during the first 60 months in relation to participants with blood tests. n = number of families at each stage. MCHC = Maternal and Child Health care Cen-tre. *“Total/Blood/Saliva” means number of families who took part
23
during a certain phase of this program/number of children with blood sample for sensitization tests during this phase/number of children with saliva samples for cortisol analyses during this phase (only rele-vant at six months of age). **Only 233 families have children who have reached the age of 60 months. All 507 families filled in a questionnaire when the child was 2 months old concerning the degree of adherence to an anthroposophic life style, which was categorized as “Anthroposophic”, “Partly anthropo-sophic” or “Non-anthroposophic”, based upon choice of antenatal clinic and parental responses to three questions: 1) “What kind of pre-school/school will your newborn child probably go to?” 2) “Has any of the parents, no matter which type of school you have planned for your child, an anthroposophic view of life?” and 3) “Is the family’s everyday life influenced by an anthroposophic view of life?” Families answering “anthroposophic school” to question 1 and “yes” to ques-tion 2 and 3 and also attending anthroposophic antenatal clinics were defined as “Anthroposophic”. Families answering conventional or any other non-anthroposophic type of school to question 1, “no” to ques-tion 2 and 3 and going to conventional antenatal clinic were defined as “Non-anthroposophic”. Any other combination of answers was de-fined as “Partly anthroposophic 4.2 Study design In the ALADDIN program (Assessment of Life style and Allergic Dis-ease During Infancy) data are collected consecutively from a birth cohort, examining the connection between lifestyle, allergy and psy-chosocial environment and underlying immunological mechanisms. An overview of the data collection process for the first (ALADDIN Original) and second (ALADDIN plus) waves of recruitment is shown in Figure 3. For the second wave of recruitment the process was re-stricted to fewer samplings and sampling occasions. Of the 507 chil-dren in the cohort 233 had reached the age of 60 months at the time when data included in the fourth - and so far last report – were ana-lyzed. Flow chart and text modified from Fredrik Stenius, thesis for doctoral degree 2011 (Lifestyle, Salivary Cortisol and Allergy in Children).
24
The full procedure (ALADDIN Original) was as follow: Data on de-mographics and different exposures were obtained from question-naires and by interviews in connection with examinations. Signs and symptoms of allergic diseases were obtained from previously used questionnaire (2, 110, 111) from health diaries, interviews and physi-cal examinations performed by the study pediatrician. Each parent filled in questionnaires during pregnancy concerning sense of coher-ence (SOC) (89, 112), a questionnaire was used to measure fear dur-ing labor and delivery (113) and at 18 months of age a questionnaire on parental social network (114). Specimens from placenta and a sample of vernix from the newborn were collected at delivery (115-117). Blood samples were collected from the parents during pregnan-cy, from cord blood and from the children at age 6, 12, 24 and 60 months in order to evaluate the allergic sensitization in blood. Fecal samples were collected from mother before and after delivery and from the child on several occasions to further evaluate the relation between lifestyle and gut micro biota in the infant (111, 118). Samples of breast milk were collected twice during child’s first months in order to evaluate the role of immune competent particles (exosomes) in the development of allergies (119). Samples of mattress dust were ob-tained in order to evaluate the role of allergens and immune stimulat-ing particles (120, 121). Salivary samples were collected in the morn-ing, afternoon and evening at 6, 12, and 24 months of age from the child and both parents.
Figure 3. Events for the ALADDIN study of families with different lifestyles followed from pregnancy until the age of 60 months of the child.
Pregnancy Prior delivery Delivery 3-6
days 3
weeks 2
months 6
months 12
months 18
months 24
months 60
months
Questionnaire X1 O X2 X1, 3 O X6 X3,7 X3,7,8
Blood mother + father X Y X4 Y
Faeces mother X X
Dust X X X X
Cord blood X
Placenta X
Vernix X
Faeces child X X X X X X X X
Breast milk X X
Health diary X X X X X Examination + interview X5 X5 X5 X5 X5
Blood child X O X O X O X O Saliva child, mother, father X O X O X O X
Skin prick test child X X
Spirometry (rev.test) X Non-bold: Only ALADDIN Original (n=330). Bold: ALADDIN Original (n=330) + ALADDIN Plus (n=222). Italic: Only ALADDIN Plus. The data collections that were used in the studies of this thesis are indicated by X O and X O. 1Sense of Coherence Scale. 2Delivery Fear Scale. 3Demographic and exposure data. 4ALADDIN plus. 5Health and exposure. 6Social network. 7Diet. 8Abdominal pain.
25
4.3 Salivary cortisol Salivary samples were collected at home from the infants and both parents during one day at age 6, 12 and 24 months, in the morning, afternoon and evening. The morning sampling occasion was defined as ‘‘a quarter after awakening and before first meal’’; afternoon as ‘‘after midday sleep’’ (or alternatively, if the child did not sleep, ‘‘one hour after midday meal’’) in the infant group and as ‘‘before dinner or — if dinner was later — before 6 PM’’ in the parental group; and evening as ‘‘before going to bed’’. The salivary samples were collected by sterile rolls (braided cotton dental rolls; Richmond Dental, Charlotte, NC), which the parents were instructed to keep in the mouth of the child until soaked with saliva. Parental saliva samples were collected by swabs (Salivette; Sarstedt Inc., Rommelsdorf, Germany), which the participants were instructed to keep in their mouth until soaked with saliva. The samples were cen-trifuged and stored at –80°C until analyzed, according to the manufac-turer’s instructions, by using the SpectriaTM Cortisol RIA (125l) kit from Orion Diagnostica Oy, Espoo, Finland (122). Parent and infant samples from the same family were analyzed in the same assay and cortisol levels were expressed in nmol/L. The procedure for salivary collection has been validated and shown to be adequate (122). 4.4 Blood samples, sensitization data
Blood samples were obtained from the parents at inclusion and from the child at 6, 12, 24 and 60 months of age. The samples were col-lected in heparin tubes and plasma was stored at –20°C. Parental sen-sitization was defined by ImmunoCAP PhadiatopTM (Phadia AB, Uppsala, Sweden) containing a mix of 11 inhalant allergens. Blood from the children at 6, 12, and 24 months of age was analyzed by ImmunoCAP (Phadia AB) for IgE to seven common allergens (cow’s milk, hen’s egg, peanut, cat, dog, birch, and timothy). At 60 months of age, when children are at risk to be sensitized to further allergens, a food mix (fx5) (Phadia AB) and PhadiatopTM with another 8 allergens (codfish, wheat flour, soy bean, Cladosporium, D. farinae, D. pter-onyssinus, horse, mugwort) were used. A study subject was classified as IgE-sensitized if IgE levels were ≥ 0.35 kUA/L, for the parents in PhadiatopTM and for the children in at least one of the allergens in-cluded at 6, 12, 24 or 60 months of age. Information on clinical mani-festations of allergy was not included in this study.
26
4.5 Sense of Coherence (SOC) questionnaire The SOC-13 with 13 items was selected for this study with the ambi-tion of optimizing compliance of parents who were to be involved in many tests and biological samplings during the whole program. This version has also proved to be applicable and relevant, both during pregnancy and in a Swedish context (123). Each item has seven op-tions with scores from 1 to 7, resulting in total scores between 13 and 91. A score of 76-91was categorized as “high”, 61-75 as “moderate” and below 61 as “low”. A high score indicates a high degree of sense of coherence. The questionnaire was mailed to the parents around ges-tational weak 28 for families recruited in the first wave and around one month of child age for families recruited in the second wave. 4.6 Statistical analyzes and ethics Statistical analyses in paper I were conducted using PASW 18.0 soft-ware and Stata 11.1, in paper II JMP 9.0 and SPSS Statistics 19.9, in paper III SPSS Statistics 20.0 and in paper IV SPSS Statistics 21.0. As salivary cortisol levels showed a skewed distribution in all study groups and on all occasions logarithmic transformation was used in all analyses involving cortisol data. Means are presented after back-transformation (geometric means). Paper I Chi-square analyses and ANOVA were used for comparison of life-style factors between the groups. ANOVA was used for comparing sampling times between the families. Linear regressions were per-formed by a model using morning-, afternoon- and evening-values of the children’s cortisol level as primary outcome. Paper II Chi-square analyses and ANOVA were used for comparison of life-style factors between the groups. ANOVA was used for comparing sampling times between the families. In addition two-way ANOVA was used for the study of circadian variation interacting with lifestyle group, with results indicating main effects of lifestyle, of time of day and of interaction between time of day and lifestyle group. These analyses were performed separately for infant age 6, 12 and 24 months. Simple linear regression computations were performed using morning, afternoon and evening values of the children as well as their
27
parent’s salivary cortisol levels as separate primary outcomes and life-style group as explanatory variable. Paper III ANOVA was used for comparing the total SOC points for mothers and fathers engaged in the three different lifestyles. T-tests were used to compare mothers and fathers with the same lifestyle in relation to total SOC points. Bivari-ate analyses were used for measuring SOC correlations in parents with different lifestyles and also their children’s levels of cortisol at 6, 12 and 24 months of age. After categorizing points of SOC in three groups (high 76–91, middle 61–75 or low 30–60), chi-square analyses were performed to analyze possible group differences in points. These analyses were carried out separately for mothers and fathers in relation to lifestyle. Finally, analyses were carried out with ANOVA compari-sons to examine possible correlations between categorized SOC points in parents with different lifestyles and also their own and their chil-dren’s levels of cortisol at 6, 12 and 24 months of age. Paper IV Chi-square analyses and ANOVA were used for comparisons of sensi-tization and lifestyle factors between the groups. Logistic regression was used to analyze whether lifestyle could predict sensitization at 6, 12, 24 and 60 months of age in a model adjusted for sex of the child, parental sensitization, parental education, mother smoking during pregnancy, number of siblings or other children living with the family, family living on a farm with animals during pregnancy and exclusive breastfeeding at age 6 months. A second model was adjusted also for cortisol. Logistic regression was similarly used to analyze if salivary cortisol level at age 6 months in the morning, afternoon and evening were related to sensitization at age 6 months, and could predict sensi-tization at age 12, 24 and 60 months. A first model was adjusted for the variables mentioned above and a second model also for lifestyle. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. The Kaplan-Meier method was used to illustrate the cumulative inci-dence of sensitization. Lifestyles as well as quartile-split cortisol lev-els at 6 months were used as main explanatory factors and differences in survival curves, i.e. children not sensitized, were tested with Log-Rank (Mantel-Cox) statistics.
28
The studies were approved by the local Ethics Committee in Stock-holm (2002-01-07, Dnr 474/01, HS) and written informed consent was obtained from all families.
29
5 RESULTS 5.1 Exposure characteristics in the lifestyle groups Sixty-eight percent of the anthroposophic parents were born in Swe-den or other Scandinavian countries, 88% of the partly anthroposophic and 92% of the non-anthroposophic parents. Twenty-eight per cent of the anthroposophic parents were from other parts of Europe, 7.5% of the partly anthroposophic parents and 7% of the non-anthroposophic. Mothers were of the same ages between groups whereas fathers in the anthroposophic group were on average two years older than in the other groups. Fathers in the anthroposophic and partly anthroposophic group more often had university education just as mothers from the partly anthroposophic group. Families with a non-anthroposophic life-style more often lived in private houses when compared with the other groups. Parental allergic sensitization did not differ significantly be-tween the three lifestyle groups. In total, 28.8% of the mothers were IgE-sensitized and 34.3% of the fathers. There were more siblings or other children living in the anthroposophic families. Many family related characteristics differed markedly between the groups before and during pregnancy, during delivery and the first 12 months of age. For example, the anthroposophic families more often preferred an organic/biodynamic diet, more often chose home deliver-ies and used less anesthetics during delivery, and mothers were to a higher extent exclusively breastfeeding. Further, children in anthropo-sophic families were less often given AD-vitamins; more commonly wore wool as underwear and had received fewer vaccinations. More details in Table 1.
Tab
le 1
. Fam
ily c
hara
cter
istic
s for
infa
nts 6
to 1
2 m
onth
s of a
ge a
rran
ged
acco
rdin
g to
an
anth
ropo
soph
ic, p
artly
an-
thro
poso
phic
or n
on-a
nthr
opos
ophi
c lif
esty
le. C
ateg
oric
al v
aria
bles
: n/N
(%).
Con
tinuo
us v
aria
bles
: Mea
n ±
SD. C
ate-
goric
al v
aria
bles
: p fo
r com
paris
ons o
f pro
porti
ons.
Con
tinuo
us v
aria
bles
: p fo
r com
paris
ons o
f mea
ns.
Ant
hrop
osop
hic
Part
ly
anth
ropo
soph
ic
Non
– a
nthr
opo-
soph
ic
P
Num
ber o
f chi
ldre
n (n
) 11
8 22
4 16
5
Pren
atal
and
del
iver
y ch
arac
teri
stic
s
Veg
etar
ian/
vega
n di
et o
ne y
ear b
efor
e pr
egna
ncy
54/1
18 (4
5.8)
92
/224
(41.
1)
12/1
65 (7
.3)
< .0
01
Veg
etar
ian/
vega
n di
et d
urin
g pr
egna
ncy
54/1
18 (4
5.8)
88
/222
(39.
6)
11/1
55 (7
.1)
< .0
01
Org
anic
a/o
bio
dyna
mic
die
t one
yea
r bef
ore
preg
nanc
y 99
/117
(84.
6)
108/
219
(49.
3)
13/1
62 (8
.0)
< .0
01
Org
anic
a/o
bio
dyna
mic
die
t dur
ing
preg
nanc
y 97
/117
(82.
9)
123/
220
(55.
9)
15/1
63 (9
.2)
< .0
01
Del
iver
y at
hom
e 46
/118
(39.
0)
47/2
24 (2
1.0)
1/
165
(0.6
) <
.001
Mid
wife
from
ant
enat
al c
linic
par
ticip
ated
at d
eliv
ery
58/1
17 (4
9.6)
77
/224
(34.
4)
1/16
3 (0
.6)
< .0
01
Ane
sthe
sia
durin
g de
liver
y 44
/118
(37.
3)
120/
223
(53.
8)
148/
164
(90.
2)
< .0
01
But
ter o
n br
ead
durin
g pr
egna
ncy
54/1
18 (4
5.8)
41
/224
(18.
3)
2/16
5 (1
.2)
< .0
01
Oliv
e oi
l as m
ain
fat i
n fo
od d
urin
g pr
egna
ncy
99/1
18 (8
3.9)
16
3/22
4 (7
2.8)
72
/165
(43.
6)
< .0
01
Nat
urop
athi
c pr
epar
atio
ns d
urin
g pr
egna
ncy
100/
115
(87.
0)
144/
217
(66.
4)
29/1
65 (1
7.6)
<
.001
Livi
ng o
n a
farm
with
ani
mal
s dur
ing
preg
nanc
y 17
/117
(14.
5)
716/
222
(7.2
) 11
/163
(6.7
) .0
41
Post
nata
l env
iron
men
tal c
hara
cter
istic
s
Cow
’s m
ilk fo
rmul
a fir
st w
eek
15/1
16 (1
2.9)
42
/224
(18.
8)
53/1
64 (3
2.3)
<
.001
Firs
t day
was
hing
of t
he b
ody
20.8
(±20
.7)
14.9
(±14
.1)
7.5
(±6.
6)
< .0
01
Firs
t clo
thin
g of
woo
l/silk
66
/ 118
(56)
40
/221
(18)
1/
162
(0.6
) <
.001
Fam
ily c
hara
cter
istic
s 2 m
onth
s
Num
ber o
f chi
ldre
n (n
) 11
1 22
1 16
4
Org
anic
a/o
bio
dyna
mic
dur
ing
brea
stfe
edin
g 2m
onth
s 10
1/11
0 (9
1.8)
13
4/21
6 (6
2.0)
16
/155
(10.
3)
< .0
01
Woo
l as u
nder
wea
r 83
/110
(75.
5)
72/2
20 (3
2.7)
6/
164
(3.7
) <
.001
Layi
ng o
n sh
eeps
kin
82/1
10 (7
4.5)
13
1/22
0 (5
9.5)
39
/164
(23.
8)
< .0
01
Has
cap
bot
h in
- and
out
door
s 74
/109
(67.
9)
74/2
20 (3
3.6)
5/
164
(3.0
) <
.001
Was
hing
the
body
< 1
/wee
k 60
/110
(54.
5)
66/2
20 (3
0.0)
17
/163
(10.
4)
< .0
01
But
ter o
n br
ead
durin
g br
east
feed
ing
2 m
onth
s 44
/110
(40.
0)
38/2
20 (1
7.3)
3/
164
(1.8
) <
.001
Oliv
e oi
l as m
ain
fat d
urin
g br
east
feed
ing
2 m
onth
90
/110
(81.
8)
158/
220
(71.
8)
66/1
64 (4
0.2)
<
.001
Livi
ng o
n a
farm
with
ani
mal
s at 2
mon
ths o
f age
16
/110
(14.
5)
11/2
19 (5
.0)
9/16
3 (5
.5)
.00
4
A
nthr
opos
ophi
c
Part
ly
anth
ropo
soph
ic
Non
– a
nthr
opo-
soph
ic
P
Fam
ily c
hara
cter
istic
s 6 m
onth
s
Num
ber o
f chi
ldre
n (n
) 11
2 20
9 16
1
Bre
astfe
edin
g at
6 m
onth
s of a
ge
Full
41/1
05 (3
9.0)
69
/189
(36.
5)
21/1
15 (1
8.3)
.0
01
Partl
y 64
/105
(61.
0)
120/
189
(63.
5)
94/1
15 (8
1.7)
Org
anic
a/o
bio
dyna
mic
dur
ing
brea
stfe
edin
g 2-
6 m
onth
s 10
0/10
6 (9
4.3)
12
5/19
1 (6
5.4)
17
/128
(13.
3)
< .0
01
Firs
t DTP
-vac
cina
tion
befo
re 6
mon
ths o
f age
4/
108
(3.7
) 63
/196
(32.
1)
148/
154
(96.
1)
< .0
01
Layi
ng o
n sh
eeps
kin
93/1
12 (8
3.0)
13
5/20
9 (6
4.6)
55
/161
(34.
2)
< .0
01
Woo
l as u
nder
wea
r 65
/111
(58.
6)
59/2
08 (2
8.4)
9/
160
(5.6
) <
.001
Cap
bot
h in
- and
out
door
s 53
/112
(47.
3)
42/2
09 (2
0.1)
0/
160
(0.0
) <
.001
But
ter o
n br
ead
durin
g br
east
feed
ing
6 m
onth
s 50
/112
(44.
6)
41/2
09 (1
9.6)
6/
161
(3.7
) <
.001
Oliv
e oi
l as m
ain
fat i
n fo
od d
urin
g br
east
feed
ing
92/1
12 (8
2.1)
12
5/20
9 (5
9.8)
56
/161
(34.
8)
< .0
01
AD
-vita
min
s to
the
child
up
to 6
mon
ths
11/1
12 (9
.8)
62/2
09 (2
9.7)
11
8/16
1 (7
3.3)
<
.001
Was
hing
the
body
< 1
/wee
k 6
mon
ths o
ld
44/1
12 (3
9.3)
48
/208
(23.
1)
22/1
58 (1
3.9)
<
.001
Livi
ng o
n a
farm
with
ani
mal
s at 6
mon
ths o
f age
12
/112
(10.
7)
13/2
09 (6
.2)
5/15
9 (3
.1)
.040
Fam
ily c
hara
cter
istic
s 12
mon
ths
Num
ber o
f chi
ldre
n (n
) 11
3 20
3 15
6
Bre
ast-f
eedi
ng a
t 12
mon
ths:
Full
2/11
3 (1
.8)
3/20
2 (1
.5)
4/15
5 (2
.6)
Partl
y 60
/113
(53.
1)
110/
202
(54.
5)
31/1
55 (2
0.0)
<
.001
Not
51
/113
(45.
1)
89/2
02 (4
4.1)
12
0/15
5 (7
7.4)
If p
artly
– m
onth
of t
erm
inat
ion
of fu
ll br
east
-fee
d 6.
3 ±
1.8
6.3
± 2.
5 5.
1 ±
2.4
<. 0
01
If n
ot –
mon
th o
f ter
min
atio
n of
bre
ast-f
eedi
ng
9.6
± 2.
1 8.
8 ±
3.2
7.4
± 2.
8 <
.001
Org
anic
/bio
dyna
mic
die
t for
the
child
10
3/11
1 (9
2.8)
16
2/20
3 (7
9.8)
28
/155
(18.
1)
< .0
01
But
ter o
n br
ead
for t
he c
hild
75
/113
(66.
4)
90/2
03 (4
4.3)
30
/156
(19.
2)
< .0
01
Oliv
e oi
l as m
ain
fat i
n fo
od fo
r the
chi
ld
57/1
13 (5
0.4)
96
/203
(47.
3)
46/1
56 (2
9.5)
.
002
Mea
t-fre
e di
et a
t 12
mon
ths o
f age
87
/112
(77.
7)
73/2
03 (3
6.0)
4/
155
(2.6
) <
.001
Fish
-fre
e di
et a
t 12
mon
ths o
f age
80
/112
(71.
4)
53/2
03 (2
6.1)
6/
155
(3.9
) <
.001
AD
vita
min
s dur
ing
first
12
mon
ths
7/11
3 (6
.2)
50/2
03 (2
4.6)
91
/156
(58.
3)
<. 0
01
Vac
cina
tion
DTP
at a
ge 3
mon
ths
10/1
13 (8
.8)
97/2
03 (4
7.8)
15
2/15
5 (9
8.1)
<
.001
Vac
cina
tion
DTP
at a
ge 5
mon
ths
5/11
3 (4
.4)
84/2
03 (4
1.4)
15
0/15
5 (9
6.8)
<.
001
Vac
cina
tion
DTP
at a
ge 1
2 m
onth
s 0/
113
(0.0
) 31
/203
(15.
3)
97/1
55 (6
2.6)
<.
001
Not
vac
cina
ted
durin
g fir
st 1
2 m
onth
s 42
/46
(91.
3)
38/6
4 (5
9.4)
0/
65 (0
.00)
<
.001
Woo
l clo
sest
to sk
in
72/1
12 (6
4.3)
56
/202
(27.
7)
1/15
4 (0
.6)
< .0
01
Was
hing
of b
ody
once
a w
eek
or m
ore
seld
om
23/1
13 (2
0.4)
18
/203
(8.9
) 4/
155
(2.6
) <
.001
34
5.2 Salivary cortisol levels in children and parents at child age of 6 months and relation to lifestyle Infants of families with an anthroposophic lifestyle had significantly lower cortisol levels on all three sampling occasions compared to in-fants in the partly anthroposophic and non-anthroposophic groups. Notably very high salivary cortisol levels were rare in the anthropo-sophic group. Child cortisol data from all ages (6, 12 and 24 months) are presented in Table 2. There were no significant differences regard-ing parental cortisol levels between the three groups, neither in the mothers nor fathers. The independent contribution of the lifestyle fac-tor on the cortisol levels of the infant was confirmed in all analyzes. 5.3 Salivary cortisol levels in children and parents at 12 and 24 months of child age and relation to lifestyle Evening cortisol levels in children from anthroposophic families were lower than in comparisons at 12 months of age (geometric means: anthroposophic 1.7, partly anthroposophic 1.9, non-anthroposophic 3.6 nmol ⁄ L; p = 0.024) and at 24 months of age (1.1, 1.8 and 2.9 nmol ⁄ L, respectively; p = 0.002). At 24 months of age, similar differ-ences were noted also for the afternoon levels (2.3, 3.3 and 3.9 nmol ⁄ L, respectively; p = 0.043).. Looking at the cortisol levels at 6, 12 and 24 months together in the same model, there were lower levels in the anthroposophic children in the afternoon (p = 0.025) and in the even-ing (p = 0.017). In the total group of children, the salivary cortisol levels decreased on almost all sampling occasions between 6 and 12 months of age as well as between 12 and 24 months of age. There were no interactions between sampling age and group meaning that the changes over time (6, 12 and 24 months) were parallel in all life-style groups. At age 12 months, the differences concerning the even-ing cortisol levels were statistically explained by a meat-free diet (p = 0.048) and at age 24 months by the anthroposophic lifestyle as such. The circadian variations were parallel in the three groups at age 12 and 24 months. No cortisol differences were observed between parents representing different lifestyles.
Tab
le 2
. Sal
ivar
y co
rtiso
l lev
els
at 6
, 12
and
24 m
onth
s of
chi
ld a
ge in
infa
nts
in th
e th
ree
grou
ps o
n al
l sam
plin
g oc
-ca
sion
s (m
orni
ng, a
ftern
oon
and
even
ing)
with
p-v
alue
s co
rres
pond
ing
to li
near
reg
ress
ions
with
ant
hrop
osop
hic
life
styl
e gr
oup
as e
xpla
nato
ry a
nd l
n (c
ortis
ol c
once
ntra
tion)
as
outc
ome
varia
ble.
Geo
met
ric m
eans
(sa
liva
corti
sol,
nmol
/L) w
ith c
onfid
ence
inte
rval
s and
num
ber o
f par
ticip
ants
.
Mor
ning
A
fter
noon
B
edtim
e M
onth
s of
age
6
12
24
6 12
24
6
12
24
G
eom
et-
ric m
ean
Con
fiden
ce
inte
rval
N
umbe
r
Geo
met
- ric
mea
n C
onfid
ence
in
terv
al
Num
ber
Geo
met
- ric
mea
n C
onfid
ence
in
terv
al
Num
ber
Geo
met
- ric
mea
n C
onfid
ence
in
terv
al
Num
ber
Geo
met
- ric
mea
n C
onfid
ence
in
terv
al
Num
ber
Geo
met
- ric
mea
n C
onfid
ence
in
terv
al
Num
ber
Geo
met
- ric
mea
n C
onfid
ence
in
terv
al
Num
ber
Geo
met
- ric
mea
n C
onfid
ence
in
terv
al
Num
ber
Geo
met
- ric
mea
n C
onfid
ence
in
terv
al
Num
ber
Ant
hrop
o-so
phic
8.
8 6.
7-11
.5
(52)
7.5
5.4-
10.4
(4
1)
6.0
3.6-
10.0
(2
8)
3.0
2.2-
4.2
(53)
3.5
2.6-
4.7
(38)
2.3
1.6-
3.4
(29)
1.9
1.4-
2.7
(50)
1.7
1.3-
2.3
(32)
1.1
0.8-
1.3
(29)
Pa
rtly
an
thro
po-
soph
ic
11.3
9.
3-13
.7
(76)
9.0
6.5-
12.4
(6
0)
10.7
7.
4-15
.4
(37)
5.5
4.4-
6.8
(77)
3.1
2.1-
4.5
(57)
3.3
2.3-
4.8
(35)
2.7
2.1-
3.6
(73)
1.9
1.2-
3.0
(53)
1.8
1.2-
2.9
(36)
N
on-
anth
ropo
- so
phic
14.9
11
.3-1
9.6
(70)
10.9
7.
9-14
.8
(57)
8.8
6.4-
12.1
(3
7)
6.8
5.0-
9.3
(73)
4.9
3.5-
6.9
(57)
3.9
2.7-
5.4
(39)
4.2
2.9-
6.0
(71)
3.6
2.3-
5.6
(52)
2.9
1.8-
4.8
(37)
p-
valu
e 0.
018
0.11
9 0.
198
0.00
1 0.
143
0.04
3 0.
006
0.02
4 0.
002
36
5.4 Parental Sense of Coherence in relation to parental and child cortisol levels as well as to lifestyle. There were no significant SOC differences between the three lifestyle groups. Nor were there any correlations between SOC scores and sali-vary cortisol levels (in mothers, fathers and children) at different sam-pling ages of the children (6, 12, 24 months of age) or at different times of the day/night cycle (morning, afternoon, bedtime). Therefore, SOC could not explain previously reported differences in the levels of cortisol among children with different lifestyles at the ages of 6, 12 and 24 months. 5.5 The relations between lifestyle group and sensitization in chil-dren up to age 60 months, also taking cortisol levels at age 6 months into account. There were large differences concerning prevalence of allergic sensiti-zation in relation to lifestyle summarized in Figure 4. Sensitization increased during the follow-up from 6 months until 60 months of age from 2.9 to 26.0% in the anthroposophic group, from 8.4 to 26.8% in the partly anthroposophic group and from 19.1 to 44.1% in the non-anthroposophic group. The strongest differences concerning sensitiza-tion appeared early, during the first year of life. Children from anthro-posophic families had lower cortisol levels in the morning, afternoon and evening. The odds ratio (OR) for anthroposophic lifestyle was always <1 and lowest at 12 months (OR, 0.10; 95% CI, 0.03-0.36). Adjusting for cortisol levels at 6 months increased these ORs at 12 and 24 months. At the same ages ORs for sensitization were elevated also for cortisol levels at 6 months. Analyzes in children not sensitized at 6 months confirmed the cortisol-related risk of sensitization. Chil-dren from families with an anthroposophic lifestyle had lower risk than comparisons of developing sensitization up to 5 years. This risk was partially explained by lower cortisol levels during infancy.
37
Figure 4. Prevalence (%) of sensitization in children at age 6, 12, 24 and 60 months from three lifestyle groups (anthroposophic, partly anthroposophic and non-anthroposophic). Significant differences be-tween the three groups: A) Non-anthro > Partly anthro p < .01 and Anthro p < .001. B) Non-anthro > Partly anthro p < .01 and Anthro p < .001; Partly anthro > Anthro p < .05. C) Non-anthro > Partly anthro and Anthro p < .05. D) Non-anthro > Partly anthro and Anthro p < .05.
19,1
27,6 24,5
44,1
8,4
13,7
13,0
26,8
2,9 4,4
15,3
26,0
0
5
10
15
20
25
30
35
40
45
50
6 12 24 60
Sens
itiza
tion
%
Months of age
Non-antro Partly
A
B C
D
38
6 SUMMARY AND INTEGRATIVE DISCUSSION Previous studies on anthroposophic lifestyle and allergy show that the children have less risk of developing allergies (1, 2, 110). All studies so far have been retrospective and have included children in school age. In view of the facts that this lifestyle seems to protect children from allergies and that different symptoms of atopy have increased dramatically during the last decades it is of general interest to study this group of children more in detail. The earlier findings have now been followed up in a prospective research program (ALADDIN), applying different approaches. One of these is to focus on stress (as measured by cortisol) as a factor that may underlie the decreased risk of allergy in anthroposophic children. As an adaptation to preschool age we chose to study stress from a psycho-physiological perspective using saliva cortisol as a marker. We have reported on low cortisol levels in these children at ages 6, 12 and 24 months (124). The differ-ences in comparisons with children from families with other lifestyles were strongest at six months, which generated a hypothesis that in-fants from anthroposophic families may be less exposed to unpleasant environmental stressors. In statistical analyzes we have only found one factor related to the anthroposophic lifestyle that could possibly un-derlie the low cortisol levels; a meat-free diet in the children statisti-cally explained the low levels at age 12 months. We have also found an association between high cortisol levels and allergy risk (98). Further, we have found support for the earlier find-ings of allergy protective qualities of the anthroposophic lifestyle (125); an anthroposophic lifestyle was associated with a lower risk of allergic sensitization up to five years of age. This risk was partially explained by lower cortisol levels during infancy. Cortisol levels at age 6 months predicted allergic sensitization up to two years of age. Children in families with a partly anthroposophic lifestyle also had substantially lower risk of sensitization, suggesting that health pro-moting elements of the anthroposophic lifestyle may successfully be incorporated into a more conventional lifestyle. To further elucidate the differences concerning cortisol levels between the children, we proceeded to study any influence of parental capacity to adapt to external stress, with a take-off point in previous studies
39
from other groups demonstrating that neither anger nor fearfulness predicted increases of cortisol in children when they were in the pres-ence of a sensitive and responsive caretaker (77, 88). Thus, parent related factors might have contributed to the varying cortisol levels between lifestyle groups in our previous reports (124, 125). Parental capacity to cope with stressors may be one such factor. A common way to scientifically evaluate this capacity is through the question-naire Sense of Coherence (SOC) (89). As stated above, Antonovsky hypothesized that: ”SOC has direct physiological consequences”, meaning that endocrine and immunologic processes may be affected (89). However, we did not find any significant SOC differences be-tween the three lifestyle groups. Nor were there any correlations be-tween SOC scores and salivary cortisol concentrations in separate analyses of mothers, fathers and children, for different sampling ages of the children (6, 12, 24 months of age) or for different parts of the day/night cycle (morning, afternoon, bedtime). Hence SOC could not explain differences in levels of cortisol among children with different lifestyles at age 6, 12 and 24 months. Since part of the allergy protective effect was not explained by low cortisol levels we investigated family characteristics of this lifestyle that may hypothetically underlie this health promoting effect. How-ever, none of all pronounced characteristics in the anthroposophic lifestyle, like home delivery, organic/biodynamic vegetables, ferment-ed vegetables with unpasteurized lacto bacteria, vaccinations and cloths of wool for the children, could explain this effect. One factor that is characteristic of an anthroposophic lifestyle is that spiritual values are emphasized. The meaning of this concept can be described in several ways. It is often confused with religiosity. Religiosity is more often thought of as tied to a collective “reinforcement and identi-ty”, such as formal religious institutions, frequency of religious at-tendance and prayer. In comparison, spirituality is often understood at the level of the individual, and can be viewed as a sense of internal peace, an impression of place within a larger purpose and connected-ness to the sacred. (126). Many studies have demonstrated that spiritu-ality may influence health and behavior. There are links between spir-ituality and physiological markers of risk for cardiovascular disease, (blood pressure, inflammation, fasting glucose and blood lipids), where higher levels of spirituality were consistently associated with lower levels of these risk factors. (127). Hypothetically, parental sense of internal peace or other aspects of spirituality may influence the
40
family environment with health promoting consequences. Interesting-ly, the spiritual development of the child is explicitly commented up-on in the 27th article in the UN Convention on the Rights of the Child: “States Parties recognize the right of every child to a standard of liv-ing adequate for the child's physical, mental, spiritual, moral and so-cial development.” There are many instruments to measure spiritual values, for instance the Daily Spiritual Experience Scale (DSES) Un-derwood and Teresi (2002), which could be applied in empirical stud-ies aiming at investigating such hypotheses. Children in families with a partly anthroposophic lifestyle also had substantially lower risk of sensitization than children in the non-anthroposophic group. This is particularly interesting since it seems to imply that some characteristics of the anthroposophic environment may be incorporated into a more typical Swedish lifestyle and still keep the sensitization preventing capacity. This, in turn, means that some aspects of the anthroposophic lifestyle may be of public health importance, if they would be used for intervention purposes. A closer investigation of the partly anthroposophic group stands out as one interesting future scientific line.
41
7 CONCLUSIONS An anthroposophic lifestyle protects from development of allergy during childhood, at least up to five years of age. This protective ca-pacity is partly mediated by low cortisol levels during infancy but is also dependent on unknown characteristics of this lifestyle. These results call for further studies on health related effects of an anthropo-sophic lifestyle. In order to reach this aim an important step would be to more exhaustively study components of this lifestyle that have not been approached in previous studies. Investigating spiritual values in parents with different lifestyles and the influence of such values on the development of allergy sensitization and salivary cortisol levels in their offspring could be one such future research line. It is of special interest to identify such components that could be incorporated into a more typical Swedish lifestyle and thereby be of public health im-portance. In this respect a closer investigation of the partly anthropo-sophic group will be important.
42
8 SVENSK SAMMANFATTNING Bakgrund: Tidigare studier om antroposofisk livsstil och allergi visar att barn från familjer med antroposofiks livsstil har mindre risk att utveckla allergi. Alla studier hittills har varit retrospektiva och barnen har varit i skolåldern. Mot bakgrund av att den här livsstilen tycks skydda barn mot allergi och att olika symtom på allergi har ökat dramatiskt under de senaste decennierna finns det ett generellt intresse att studera den här barngruppen mer ingående. De tidigare resultaten har nu följts upp med ett omfattande prospektivt projekt ALADDIN ((Assessment of Life style and Allergic Disease During Infancy), med olika infallsvinklar. En är inriktad på stress, som mäts genom kortisol i saliv, som skulle kunna vara en orsak till den min-skade risken för allergi hos barn från antroposofiska familjer. Syfte: Den här avhandlingen bygger på data hämtade från ALADDIN och studerar betydelsen av familjens livsstil i förhållande till allergisk sensibilisering tidigt i barnens liv i relation till psykosociala faktorer och kortisol i saliv som en markör för stress. Metod: Totalt rekryterades 552 familjer under mammans graviditet eller då barnet var cirka 1 månad gammal. En grupp på 330 familjer rekryterades mellan september 2004 och november 2007, och en annan grupp familjer mellan mars 2008 och januari 2011. Familjerna kom antingen från en MVC/BVC med antroposofisk inriktning eller från vanlig MVC/BVC. Data om miljö- och livsstilfaktorer samlades in genom frågeformulär och intervjuer. Föräldrarnas förmåga att hantera stress värderades genom att de besvarade frågeformuläret ”Känsla av Sammanhang” (KASAM; Antonovsky). Salivprov för analys av kortisol samlades in i hemmet från både föräldrar och barn. Blodprov för analys av allergiantikroppar samlades in från föräldrar och barn. Resultat: Många livsstilsfaktorer före och under graviditet samt under tidig barndom skilde sig markant åt mellan familjerna. Barn från an-troposofiska familjer hade lägre kortisolnivåer jämfört med jämnåriga från familjer med en mer konventionell livsstil. Det gällde vid alla tre mättillfällen under dagen vid 6 månaders ålder och vid enstaka mät-tillfällen vid 12 och 24 månaders ålder. Det fanns ingen skillnad i varken kortisolnivåer eller KASAM-poäng mellan familjer med olika
43
livsstilar. En antropofisk livsstil visade minskad risk för allergisk sen-sibilisering upp till fem års ålder. Den minskade risken berodde delvis på lägre kortisolnivåer under första spädbarnsåret. Barn från familjer med delvis antroposofisk livsstil hade också en betydande lägre risk att bli sensibiliserade. Slutsatser: En antroposofisk livsstil minskar risken för allergi under barndomen, åtminstone upp till fem års alder. Denna skyddseffekt medieras delvis av låga kortisolnivåer under spädbarnsåret men den påverkas också av hittills icke identifierade egenskaper hos denna livsstil. Fortsatta studier i syfte att utröna vilka dessa egenskaper är framstår som angelägna.
44
9 ACKNOWLEDGEMENTS First I would like to thank all parents with their children who have participated so strongly in all the surveys and thus be able to contrib-ute to everyone's efforts to better understand how we shall reduce the risk that children will develop allergy. Then I would like especially to thank: Frank Lindblad, my principal supervisor, for your firm but friendly way to lead me through tangled forests and deep valleys up against unsuspecting hilltops with wide views of the wonderful world that we all want to try to understand better. Your way to show the way can be a model for many others. Thöres Theorell, my supervisor, for your way of thinking in the world of natural science, where your knowledge has become some kind of wisdom. Johan Alm, my supervisor and friend who once started my scientific journey that has led to so many fruitful results, a friendship and grati-tude without limit. Hans Arinell, statistician, for always be prepare, with greatest pa-tience to answer my questions. I am so grateful for your help Hans! Fredrik Stenius, for nice collaboration and always prepare to help. Margareta Eriksson, nurse and coordinator for always patiently and kindly answer all my questions. All the staff at Kirstens familjehälsa and Järna vårdcentral. Colleges at Vidarkliniken and the team at Integrative Care science centre for supporting me along the scientific way. The ALADDIN team for all the cooperation during many years, and especial Annika Scheynius, Göran Pershagen and Gunnar Lilja who gave me confidence to dare to start a way into the scientific world which have now led to a thesis.
45
Helena Marell Hesla college on the same way to a thesis, Lars Holmberg and Anne-Christine Sjöbeck for cortisol analyzes and bio-med. analysts Carina Wallén. This work was supported by the Centre for Allergy Research Karolin-ska Institutet, the ‘Mjölkdroppen’ Society, the Swedish Asthma and Allergy Research Association, the Swedish Research Council, Swe-dish Research Council for Working Life and Social Research, the Swedish Society of Medicine, the Cancer- and Allergy Fund, the Ek-haga-, the ‘Frimurare Barnhuset’ in Stockholm-, the Gyllenberg-, the Vidar-, the Hesselman-, the Samariten- and the Vårdal foundation. Thermo Fischer Scientific provided the study with free reagents.
46
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Acta Universitatis UpsaliensisDigital Comprehensive Summaries of Uppsala Dissertationsfrom the Faculty of Medicine 992
Editor: The Dean of the Faculty of Medicine
A doctoral dissertation from the Faculty of Medicine, UppsalaUniversity, is usually a summary of a number of papers. A fewcopies of the complete dissertation are kept at major Swedishresearch libraries, while the summary alone is distributedinternationally through the series Digital ComprehensiveSummaries of Uppsala Dissertations from the Faculty ofMedicine. (Prior to January, 2005, the series was publishedunder the title “Comprehensive Summaries of UppsalaDissertations from the Faculty of Medicine”.)
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