6th nationwide anthropological survey of children and adolescents 2001 bláha p.*, vignerová j.**...
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6th Nationwide Anthropological Survey of Children
and Adolescents 2001
Bláha P.*, Vignerová J.**
*Faculty of Science, Charles University, Prague
National Institute of Public Health
Czech Republic
• Apart from genetic determinants, growth of an individual is to a great extent influenced by external factors (familly backround, socio-economics conditions of the society, health care system, social system etc.).
FENOTYP OF AN INDIVIDUAL =FENOTYP OF AN INDIVIDUAL = GENETIC FACTORS + ENVIRONMENTAL FACTORS +
INTERACTION BETWEEN GENETIC AND ENVIRONMENTAL FACTORS
FAMILYFAMILYENVIRONMENTENVIRONMENT
HEALTH,HEALTH,GROWTHGROWTH
SESSES
PHYSICALPHYSICALENVIRONMENTENVIRONMENT STRESSSTRESS
Flinn M.V., England B.G., American Journal of Physical Anthropology, 1997
Material I.
• 1895: Measurements of 100.000 school children - Czech physician and anthropologist Matiegka (Matiegka J., 1927, Somatology of school children. Nakl. ČSAV a umění, Praha.) – He founded tradition of Nationwide Anthropological Surveys.
• 1800-1809: Mean heights and s.d. in military boarding-school children born between 1800-1809 (in Bohemia and Moravia), recorded in Vienna (Komlos J: Patterns of children’s growth in East-central Europe in the eighteenth century. Annals of Human Biology, 1986, Volume 13, No. 1, pp. 33 - 48.)
Material I: NATIONWIDE ANTHROPOLOGICAL
SURVEYS IN CR
• Every ten years - 1951, 1961, 1971, 1981, 1991, 2001
• Number of children per survey:
80.000 – 100.000 (3 to 5 % of the population of given age)
• Age: 0 to 19 years
Praha
NATIONWIDE ANTHROPOLOGICAL SURVEYS IN CR (1951 to 2001)
• Preschool children: in clinics, by instructed health professionals, mainly paeditricians.
• School children: teachers, provided with detailed written instructions.
• Anthropological measurements: height, body weight, circumferences of the head, arm, waist and hip – Martin Saller method.
• Questionnaires for children: dietary habits, sports activity, TV watching and PC games.
• Questionnaires for parents: parental height, weight, educational level, number of children in the family, breastfeeding and health status of their child.
METHODS
• Original data available from : 1951, 1981, 1991 and 2001.
• For other surveys: sample sizes for each age group, average values and standard deviations are available, for 1895 only average values.
• We have used only these summary values for the growth curves construction.
• Weighted polynomial smoothing spline of 3rd order was used for construction of the growth curves of the height.
• Weights were proportional to sample sizes at the particular time point.
• Its first derivative was then computed to obtain growth velocity.
-2
-1,5
-1
-0,5
0
0,5
1
1,5
2
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Age years
Z-score
195119711991WHO20011895
-2
-1,5
-1
-0,5
0
0,5
1
1,5
2
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Age years
Z-score
195119711991WHO20021895
BOYS GIRLS
Z-SCORE ACCORDING WHO REFERENCE VALUES
Height
Adult height: 1951 - 172.4 (s.d. 6.6)2001 - 180.4 (s.d. 7.0) dif. 8.0 cm
Adult height: 1951 - 161.0 (s.d. 5.6)2001 - 167.2 (s.d. 6.4) dif. 6.1 cm
BOYS GIRLS
-2
-1,5
-1
-0,5
0
0,5
1
1,5
2
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Age years
Z-score
195119711991WHO20011895
-2
-1,5
-1
-0,5
0
0,5
1
1,5
2
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Age years
Z-score
195119711991WHO20011895
Z-SCORE ACCORDING WHO REFERENCE VALUES
Weight
BIRTH WEIGHT- % in weight categories Boys
0%10%20%30%40%50%60%70%80%90%
100%
1955 1981 2001
Year
4500g <
3500-4499g
2500-3499g
1500-2499g
< 1500g
Czech Helath Statistics Yearbooks
BIRTH WEIGHT - % in weight categories Girls
0%
20%
40%
60%
80%
100%
1955 1981 2001
Year
4500g <
3500-4499g
2500-3499g
1500-2499g
< 1500g
Czech Helath Statistics Yearbooks
• 1951 – no data• Since 1975 no
changes• Boys: 50.5 cmBoys: 50.5 cm
3400 g3400 g• Girls: 49.7 cmGirls: 49.7 cm 3270 g3270 g
MEAN BIRTH LENGTH AND WEIGHT
The secular trend of height appears significant from the category of two years olds onwards.
SECULAR TREND OF HEIGHTGrowth curves
Boys
80
100
120
140
160
180
200
4 6 8 10 12 14 16 18Age years
cm
20011991198119711961195118951800-09
Girls
80
100
120
140
160
180
200
4 6 8 10 12 14 16 18Age years
cm
2001199119811971196119511895
3
1,5
0,8
0,2
0
0,5
1
1,5
2
2,5
3
3,5
41985 1951 1971 1991
Years
• In 1895 it was 3 years later3 years later (at 12 years) that boys and girls reached the same values of height and weight of today’s 9 year olds.
• 1951 – 1.51.5 years later
• 1971 – 0.80.8 years later
• 1991 – 0.2 0.2 years later
• The same applies to today’s 10 and 11 year old children
HEIGHT AND WEIGHT Comparison of age
Mean values of height and weight of boys and girls 9 year olds
- in 2001
6 8 10 12 14 16
34
56
7
boysgirls
11,15
Age years
13,327,16
7,87
cm • A comparison of a study from 90s with one from 70s shows shift of growth spurt towards younger age categories: 4 months4 months in girls and in girls and 3 months3 months in boysin boys
1975 1995
Girls 11.5 11.1
Boys 13.6 13.3
• The time shift between boys and girls in the onset of adolescent growth spurt is almost 2 years.
GROWTH VELOCITY OF THE HEIGHT(cm per year)
Longitudinal studies
00.10.20.30.40.50.60.70.80.9
1
10 11 12 13 14 15 16 17
Age years
Pro
bal
ity
Girls
Boys
Number: GIRLS: 12.837 BOYS: 9.645
Mean age of menarche:
(50 % YES, 50 % NO)1991: 13.00 years2001: 13.01 years
Mean age of voice-breaking:
1991: 14.50 years2001: 13.84 years
Corresponds with shifting of secular trend of height
AGE OF MENARCHE AND VOICE-BREAKING1991, 2001
Logistic regression
0.01 y.
0.66 y.
AGE OF ADIPOSITY REBOUNDMethod
• Age of adiposity rebound was defined as the local minimum position of the fitted BMI curve.
6.4
5.3 5.45.2
4
4.5
5
5.5
6
6.5
7
1951 1981 1991 2001
Age
yea
rs
AGE OF ADIPOSITY REBOUNDNationwide Anthropological Surveys
6.2
5.5 5.5
4.9
4
4.5
5
5.5
6
6.5
7
1951 1981 1991 2001
Age
yea
rs
BOYS GIRLS
Results for 50th centile, for higher centiles in the earlier age, for lower centiles later
1.3 1.2
BMI EMPIRICAL CENTILE CHARTS1951, 1991
10
12
14
16
18
20
22
24
26
28
30
2 4 6 8 10 12 14 16 18
Age years
kg/m2
97.perc.
90.perc.
50.perc.
10.perc.
3perc.
1951-97 p.
1951-90 p.
1951-50 p.
1951-10 p.
1951-3 p.
10
12
14
16
18
20
22
24
26
28
30
2 4 6 8 10 12 14 16 18
Age years
kg/m2
97. perc.
90. perc.
50. perc.
10. perc.
3. perc.
1951-97 p.
1951-90 p.
1951-50 p.
1951-10 p.
1951-3 p.
BOYS GIRLS
BMI EMPIRICAL CENTILE CHARTS1951, 1991
Adiposity rebound: in 1951 - 1.5 year later
0102030405060708090
100 110 120 130 140 150 160 170
cm
kg
97
75
50
25
3
BOYS
0102030405060708090
100 110 120 130 140 150 160 170
cm
kg
97
75
50
25
3
GIRLS
WEIGHT-HEIGHT RATIO Empirical centile charts
1951, 2001
PERCENTAGE OF OVERWEIGHT AND OBESE CHILDREN
Reference data: WHO and IOTF recommendationsAge 7 – 11 years
0
5
10
15
20
25
30
35
1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Year
%
USAEuropeCzech Rep.
Report of the International Obesity Task Force, 2004
PERCENTAGE OF INHABITANTSBY EDUCATIONAL LEVEL
in the Czech Republic
0%
20%
40%
60%
80%
100%
1970 1980 1990 2000
University
High school
Apprentice
Basic
Czech Statistics Yearbooks
Socio-economic conditions in which the child grows up are to a considerabledegree affected by the level of education of his or her parents.
HEIGHT, WEIGHT-HEIGHT RATIOby parental educational level
Survey 2001, age 7.00 - 8.99 years (n = 3478) – before growth spurt
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Boys Girls
1
2
3
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0.25
Boys Girls
1
2
3
Parents’ education:1. both lower level (basic and apprenticeship)2. one parent lower and one highter level3. both parents higher level (high school, university)
Height Weight-height ratioZ-scoreZ-score
Z-score: using WHO reference data
MEAN BODY HEIGHTBY SIZE OF THE COMMUNITY
AGE 7.00 YEARS
100
110
120
130
1 2 3 4
1951
2001
Statisticaly significant differences in 1951Not statisticaly significant differences in 2001
BOYS
100
110
120
130
1 2 3 4
1951
2001
GIRLScm cm
1 - village2 - small cities3 - large cities4 - Prague
Abstract: T. J. Cole: The secular trend in human physical T. J. Cole: The secular trend in human physical growth: a biological view. growth: a biological view. Economics &Human Biology, Vol. 1, Issue 2, June 2003, pp. 161-168
… In Northern Europe, adult height has In Northern Europe, adult height has largely stabilisedlargely stabilised, and the age of menarche has also settled at around 13 years, while weight continues to while weight continues to increase due to obesityincrease due to obesity. The increase in height from one generation to the next occurs mainly in the first 2 years of life, due to increases in leg length. …
CONCLUSION
• The development of physical characteristics, in particular height and weight of children and adolescents, is a sensitive indicator for socio-economic conditions in which the children grow up and mature.
• Throughout the period of the 20th century - in line with improvements in socio-economic conditions - the physical height was increasing in all age categories.
• A shift in onset and peak of the growth spurt occured towards lower age categories. The period of its cessation, however, remains the same since 1960.
• The shift in growth spurt is linked with shift in the timing of onset of the sexual maturity.
• A shift also occured in the adiposity rebound. • The proportion of children and adolescents with overweight
and obesity is also increasing, although to a lesser degree than in other developed countries.