Secular changes in standing height, sitting height and sexual maturation of Chinese--the Hong Kong Growth Study, 1993.

In 1993 a territory-wide cross-sectional growth survey on 25,000 Chinese children from birth to 18 years was performed in Hong Kong. Compared to the last growth survey in 1963, definite secular changes were observed. There was an increase of final adult standing height of 3.6 cm in boys and 2.7 cm in girls, in which 1.8 cm and 0.5 cm respectively for boys and girls was accounted for by the sitting height. Thus most of the height increase had occurred in the leg length in girls, but in boys only half of it. The height difference was more marked during the pubertal years because secular change had brought about an earlier sexual maturation, including an advancement of median menarcheal age by 0.5 year, coupled with an earlier growth spurt. This paper also provides the first growth standards for Chinese from birth to 18 years, with percentile charts on both standing height and sexual maturation in boys and girls.