This article was downloaded by: [University of California Santa Cruz]On: 02 December 2014, At: 15:52Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registeredoffice: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

Biological Rhythm ResearchPublication details, including instructions for authors andsubscription information:http://www.tandfonline.com/loi/nbrr20

Infradian rhythmic variations ofsalivary estradioland progesterone inhealthy menPeter Celec a b , Daniela Ostatníková c , Július Hodosy c , MartinaSkokňová c , Zdeněk Putz d & Matúš Kúdela e

a Institute of Pathophysiology, Faculty of Medicine, ComeniusUniversity , Bratislava, Slovak Republicb Department of Molecular Biology, Faculty of Natural Sciences ,Comenius University , Bratislava, Slovak Republicc Institute of Physiology, Faculty of Medicine, ComeniusUniversity , Bratislava, Slovak Republicd National Institute of Endocrinology and Diabetology , L'ubochňa,Slovak Republice Department of Zoology, Faculty of Natural Sciences , ComeniusUniversity , Bratislava, Slovak RepublicPublished online: 21 Aug 2006.

To cite this article: Peter Celec , Daniela Ostatníková , Július Hodosy , Martina Skokňová , ZdeněkPutz & Matúš Kúdela (2006) Infradian rhythmic variations of salivary estradioland progesterone inhealthy men, Biological Rhythm Research, 37:01, 37-44, DOI: 10.1080/09291010500410541

To link to this article: http://dx.doi.org/10.1080/09291010500410541

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the“Content”) contained in the publications on our platform. However, Taylor & Francis,our agents, and our licensors make no representations or warranties whatsoever as tothe accuracy, completeness, or suitability for any purpose of the Content. Any opinionsand views expressed in this publication are the opinions and views of the authors,and are not the views of or endorsed by Taylor & Francis. The accuracy of the Contentshould not be relied upon and should be independently verified with primary sourcesof information. Taylor and Francis shall not be liable for any losses, actions, claims,proceedings, demands, costs, expenses, damages, and other liabilities whatsoever orhowsoever caused arising directly or indirectly in connection with, in relation to or arisingout of the use of the Content.

This article may be used for research, teaching, and private study purposes. Anysubstantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,systematic supply, or distribution in any form to anyone is expressly forbidden. Terms &Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014

Infradian rhythmic variations of salivary estradioland progesterone in healthy men

PETER CELEC1,2, DANIELA OSTATNIKOVA3, JULIUS HODOSY3,

MARTINA SKOKNOVA3, ZDENEK PUTZ4, & MATUS KUDELA5

1Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic,2Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Bratislava,

Slovak Republic, 3Institute of Physiology, Faculty of Medicine, Comenius University, Bratislava,

Slovak Republic, 4National Institute of Endocrinology and Diabetology, L’ubochna, Slovak Republic, and5Department of Zoology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic

AbstractBackground. Circadian and circannual rhythms of sex steroids in men have been well described, butinfradian dynamics of estradiol and progesterone in men are unknown. These hormones play a role inthe physiology as well as in the pathophysiology of various clinical entities, and their chronobiologymight be of importance.Aim. Infradian dynamics of salivary estradiol, testosterone, and progesterone were analysed for thepresence of cyclic patterns.Subjects and methods. Five young healthy men collected saliva samples for 30 consecutive days. Salivaryestradiol, testosterone, and progesterone were measured using radioimmunoassay. Analysis of RhythmicVariance (ANORVA) was used and potential period lengths of 3 – 15 days were evaluated.Results. No infradian rhythms were found in testosterone and progesterone, but a significant (p5 0.03)rhythm at a period length of 12 days was found in salivary estradiol levels.Discussion. We believe that this is the first study to describe a 12-day (duodecimal) rhythm of salivaryestradiol in men. This finding might be of importance for physiological and pathophysiological research,though the pattern needs to be investigated in larger studies.

Keywords: Infradian dynamics, estradiol, progesterone, male duodecimal rhythm, ANORVA

Introduction

Despite a number of animal and clinical studies, the physiological and pathophysiological

roles of female sex steroids in men is unclear, in spite of the fact that it has been repeatedly

shown that both hormones influence the male reproductive, cardiovascular, and central

nervous systems (Hargreave et al. 1988; Jiang et al. 1996; Gron et al. 1997; Gill-Sharma et al.

2001). Some information is available about the diurnal rhythm (Kalra & Kalra 1977;

Simpkins et al. 1981; Juneja et al. 1991), but little is known about the circannual cycle

(Andersson et al. 2003). However, infradian rhythms with a period length of more than

Correspondence: Peter Celec, Galbaveho 3, 841 01 Bratislava, Slovak Republic. E-mail: petercelec@gmail.com;

www.biomed.szm.com

Biological Rhythm Research

February 2006; 37(1): 37 – 44

ISSN 0929-1016 print/ISSN 1744-4179 online � 2006 Taylor & Francis

DOI: 10.1080/09291010500410541

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014

24 hours are almost unknown in men, in contrast to the well-described circalunar cycle in

women, which can be described as an infradian rhythm. The aim of our study was to search

for infradian rhythms in estradiol, progesterone, and testosterone in young healthy men. In

this study, we have concentrated on potential rhythms with a period length between 3 and 15

days. Longer periods require a larger study, which is currently in preparation. The mechanism

of infradian rhythms is unknown, although some speculations exist regarding the role of the

lunar cycle in their evolution; the current study was not designed to investigate this aspect of

infradian rhythms.

Subjects and methods

Five young healthy men, aged 20 – 21 years, collected saliva samples during 30 consecutive

days in September 2000. Sampling was performed between 08.00 and 10.00 am every day.

The volunteers were also asked to refrain from sexual activity and drinking alcohol throughout

the study (Stearns et al. 1973; Purohit 2000). The saliva samples were kept frozen in a freezer

until analysed. Salivary levels of estradiol, progesterone, and testosterone were measured by

Figure 1. Individual time series profiles of salivary testosterone levels (nmol/l). Although no cyclic variation has been

found, note the relatively low intra-individual variability of the levels (variation coefficient¼13.9%). No cyclic

variation in the data was found.

38 P. Celec et al.

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014

radioimmunoassay. Missing values (3 out of 150) and outlying values (1 out of 150) were

estimated by calculated intrapolation. Statistical analysis was performed using the ANORVA

(analysis of rhythmic variance) method (Celec 2004). ANORVA is based on the premise that

cyclic data exhibit low variance if the time distance between them equals one period. Our study

was designed to investigate the existence of a potential cycle with a period length between 3 and

15 days. All periods within this range were examined, and the resulting average variance was

used as a criterion for the existence of the tested period in the data (criterion c). Comparing the

results from criterion c with randomized number sets made it possible to calculate p-values and

quantify the probability for the presence of a given rhythm (Celec 2004).

Results

The average salivary testosterone levels were 0.2997+ 0.0415 nmol/l, with a range of values

between 0.0424 and 0.5938 nmol/l (Figure 1). The individual time series for progesterone are

Figure 2. Individual time series profiles of salivary progesterone levels (nmol/l). Although no cyclic variation has been

found, note the high intra-individual variability of the levels (variation coefficient¼ 42.7%). Arrows indicate peak

clusters that could be part of a longer cycle.

Infradian dynamics of salivary sex hormones in men 39

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014

shown in Figure 2. The daily measurements ranged between 0.0177 and 0.2446 nmol/l, with

an average level of 0.1193+ 0.0508 nmol/l. For estradiol, the salivary levels ranged between

0.3272 and 3.7240 pmol/l with an average of 1.5217+ 0.6251 pmol/l (Figure 3). The

variation coefficients were 42.7% and 41.1% for progesterone and estradiol, respectively.

These variabilities were much higher than that for testosterone (13.9%).

Calculated values for criterion c for testosterone, progesterone, and estradiol are shown in

Figures 4a, 5a and 6a, respectively. Comparison of this criterion with that obtained from

randomized number sets, and using one-tailed Student t-tests, indicated no cyclic variation in

salivary testosterone (Figure 4b) and in salivary progesterone (Figure 5b), but salivary

estradiol showed a significant (p5 0.03) rhythm at a period length of 12 days (Figure 6b).

Discussion

In our previous studies, we found infradian rhythms of salivary testosterone in men (Celec

et al. 2003). The circatrigintan cycle, in particular (with a period length of 30 days), has a

Figure 3. Individual time series profiles of salivary estradiol levels (pmol/l). A significant cyclic variation has been

found at the period length of 12 days (p5 0.03). Due to the low signal-to-noise ratio, it is difficult to find the rhythm

without the use of statistical procedures. Except for proband XY5, note the high intra-individual variability of the

levels (variation coefficient¼41.1%). Arrows show peak couples that might be an indicator for the proposed rhythm.

40 P. Celec et al.

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014

considerable influence on cognitive performance and probably also on other hormone-

dependent variables (Celec et al. 2002). However, these studies were designed to look for

longer periods of testosterone rhythmicity, whereas the current study concentrated on periods

between 3 and 15 days only, in which domain no significant periodicities for testosterone were

found. Studies concerning the chronobiology of female sex hormones in men are rare,

particularly those investigating infradian rhythms. However, infradian variations deserve more

attention, particularly when it is taken into account that the physiological and pathophysio-

logical effects of progesterone and estradiol are currently the subject of intense scientific and

clinical investigation (Carlsen et al. 2000; Jeyaraj et al. 2001; Vermeulen et al. 2002).

Although no periodicities have been found for progesterone, the high intra-individual

variability has to be taken into account when analysing the influence of progesterone levels on

other biological variables. Moreover, infradian rhythmic changes might be hidden if the time

period is longer than 15 days (Figure 2); to uncover such hidden rhythms requires longer

periods of data collection.

Figure 4. (a) Criterion c calculated using the ANORVA method for salivary testosterone levels (solid curve) in

comparison to the criterion c for randomized data sets (dotted curves). No rhythmic variations were found. The

dotted curves show a range for criterion c from randomized datasets. If the calculated criterion c (solid curve) for a

specific period length is markedly below this range, this predicts a significant cyclical component with the specific

period length. (b) P-values in comparison to alpha¼0.05 for the tested periods in time series of salivary testosterone.

No significant rhythmic variations were found.

Infradian dynamics of salivary sex hormones in men 41

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014

We believe that we are the first to find a 12-day (duodecimal) rhythm of salivary estradiol in

men. The mechanism that might explain the existence of this infradian rhythm is unknown.

Currently, astronomical, biological, or social factors, known to influence hormonal levels,

cannot be excluded. By sampling at the same time each day, we have excluded the effects of

the circadian rhythm, though interactions with rhythms of longer period lengths are possible.

We are aware of the low number of participants in this study and that further studies with

higher number of subjects are required. Nevertheless, our results might have implications in

basic and clinical endocrinology and should be considered in biomedical research. As subtle

inter-individual differences in sex hormone levels might be associated with the risk of

cardiovascular diseases, hormone-dependent cancer and with the variability of many

psychological parameters, the identification of an infradian rhythm of estradiol in men

should be helpful in endocrine research where estradiol levels in men are measured, in

pathophysiological studies and in clinical diagnostics.

Figure 5. (a) Criterion c calculated using the ANORVA method for salivary progesterone levels (solid curve) in

comparison to the criterion c for randomized data sets (dotted curves). No rhythmic variations were found. Note the

nadir at period length of 11 days indicating a non-significant cyclic component in the time series. Larger studies

should prove the existence of this potential rhythm. (b) P-values in comparison to alpha¼0.05 for the tested periods

in time series of salivary progesterone. No significant rhythmic variations were found.

42 P. Celec et al.

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014

Acknowledgments

We are grateful to the volunteers for participating in this study and to our families for

continuous support. This study was financially supported by the Ministry of Education of the

Slovak Republic grant VEGA 1/0550/03 and by the Science and Research Support Agency

grant APVT-20-003104.

References

Andersson AM, Carlsen E, Petersen JH, Skakkebaek NE. 2003. Variation in levels of serum inhibin B, testosterone,

estradiol, luteinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin in monthly

samples from healthy men during a 17-month period: possible effects of seasons. J Clin Endocrinol Metab

88:932 – 937.

Carlsen CG, Soerensen TH, Eriksen EF. 2000. Prevalence of low serum estradiol levels in male osteoporosis.

Osteoporos Int 11:697 – 701.

Celec P. 2004. Analysis of rhythmic variance – ANORVA. A new simple method for detecting rhythms in biological

time series. Biol Res 37:777 – 782.

Figure 6. (a) Criterion c calculated using the ANORVA method for salivary estradiol levels (solid curve) in

comparison to the criterion c for randomized data sets (dotted curves). A significant nadir is found at the period length

of 12 days. Criterion c for this period is significantly lower than for randomized data sets (p5 0.03). (b) P-values in

comparison to alpha¼ 0.05 for the tested periods in time series of salivary estradiol. A significant 12-day rhythm was

found (p50.03).

Infradian dynamics of salivary sex hormones in men 43

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014

Celec P, Ostatnikova D, Putz Z, Hodosy J, Bursky P, Starka L, Hampl R, Kudela M. 2003. Circatrigintan cycle of

salivary testosterone in human male. Biological Rhythm Research 34:305 – 315.

Celec P, Ostatnikova D, Putz Z, Kudela M. 2002. The circalunar cycle of salivary testosterone and the visual-spatial

performance. Bratisl Lek Listy 103:59 – 69.

Gill-Sharma MK, Dsouza S, Padwal V, Balasinor N, Aleem M, Parte P, Juneja HS. 2001. Antifertility effects of

estradiol in adult male rats. J Endocrinol Invest 24:598 – 607.

Gron G, Friess E, Herpers M, Rupprecht R. 1997. Assessment of cognitive performance after progesterone

administration in healthy male volunteers. Neuropsychobiology 35:147 – 151.

Hargreave TB, Elton RA, Sweeting VM, Basralian K. 1988. Estradiol and male fertility. Fertil Steril 49:871 – 875.

Jeyaraj DA, Mani Maran RR, Aruldhas MM, Govindarajulu P. 2001. Progesterone induced modulations of serum

hormonal profiles in adult male and female rats. Endocr Res 27:223 – 232.

Jiang N, Chopp M, Stein D, Feit H. 1996. Progesterone is neuroprotective after transient middle cerebral artery

occlusion in male rats. Brain Res 735:101 – 107.

Juneja HS, Karanth S, Dutt A, Parte P, Meherjee P. 1991. Diurnal variations and temporal coupling of bioactive and

immunoactive luteinizing hormone, prolactin, testosterone and 17-beta-estradiol in adult men. Horm Res

35:89 – 94.

Kalra PS, Kalra SP. 1977. Circadian periodicities of serum androgens, progesterone, gonadotropins and luteinizing

hormone-releasing hormone in male rats: the effects of hypothalamic deafferentation, castration and

adrenalectomy. Endocrinology 101:1821 – 1827.

Purohit V. 2000. Can alcohol promote aromatization of androgens to estrogens? A review. Alcohol 22:123 – 127.

Simpkins JW, Kalra PS, Kalra SP. 1981. Alterations in daily rhythms of testosterone and progesterone in old male

rats. Exp Aging Res 7:25 – 32.

Stearns EL, Winter JS, Faiman C. 1973. Effects of coitus on gonadotropin, prolactin and sex steroid levels in man.

J Clin Endocrinol Metab 37:687 – 691.

Vermeulen A, Kaufman JM, Goemaere S, van Pottelberg I. 2002. Estradiol in elderly men. Aging Male 5:98 – 102.

44 P. Celec et al.

Dow

nloa

ded

by [

Uni

vers

ity o

f C

alif

orni

a Sa

nta

Cru

z] a

t 15:

52 0

2 D

ecem

ber

2014