Long-term Changes in the Growth of Czech Children Population
Vignerová J.1, Bláha P.2, Brabec M.1, Kobzová J.3, Krejčovský L.4, Riedlová J.5
Státní zdravotní ústav, Praha1 ředitel MUDr. J. Volf, PhD Přírodovědecká fakulta UK, Praha2 děkan prof. RNDr. P. Kovář, CSc. Pedagogická fakulta Jihočeské univerzity, České Budějovice3 děkan prof. RNDr. M. Papáček, CSc. Pedagogická fakulta Univerzity Palackého, Olomouc4 děkan prof. PhDr. F. Mezihorák, CSc. 3. lékařská fakulta UK, Praha5 děkan doc. MUDr. B. Svoboda, CSc. |
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Summary:
Based on the results of six nation-wide anthropological surveys of children and adolescents
and on the results of survey from year 1895 the analysis of secular trend of body height in children
and adolescents in the Czech Republic (formerly the Czech countries of Czechoslovakia) was
performed. The analysis is supplemented with data on body height of boys from Vienna Military
Academy from the years 1800-1809. The growth data (year and sex specific height averages) were
fitted by polynomial spline of 3rd order (with weighting derived from standard deviations and
sample sizes).
The gradual increments of average body height of the Czech children population in age categories from 7 years to adult age is documented for boys since 1800, for girls from 1895. The greatest
difference was noted for 15-year boys, where the body height increased by 30 cm over the last
200 years. Similarly, for girls the highest difference was noted for 12-year olds (18 cm between
1895 and 2001). Secular trend of body height slows down in the last decade, particularly for girls.
The period of the fastest growth, derived by differentiation of the fitted average growth curves
shifts to younger age categories gradually. For boys, the period of maximum growth velocity
moved from 16 to 13 years, while for girls from 11.5 to 11. Pubertal growth spurt location shift is
probably connected to the sexual maturation timing changes. In the 1895, the mean age of menarche
for girls was 15.6 years, whereas in 1991 and 2001, it was 13 years. The mean age of mutation
for boys was 14.5 years in 1991 and it shifted to 13.8 years. This observation corresponds to a more
prominent slow-down of the secular trend of body height in girls and a less prominent diminution
in boys.
The 18 years old boys presently reach the average body height 180.1 cm, which means an increase
of adult body height by 12 cm in comparison with the year 1895. The average age of present
18-year old girls is 167.2 cm, which is more then 10 cm higher than in 1895. In view of the changes
of socio-economics conditions there is not only a gradually increased body height, but the
whole developmental phase of the individual to reaching adulthood speeds up.
Key words:
body height, secular trend, growth velocity, maturation
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