Distribution of Waist and Hip Circumference and Waist-to-hip Ratio Among Children and Adolescents in Changsha

Objective To study the distribution of waist and hip circumference and waist-to-hip ratio in children and adolescents aged between 11 and 18 years in Changsha. Methods Two of middle schools in urban areas of Changsha were randomly selected and 2,490 students aged between 11 and 18 years who attended the Physical Fitness and Health Surveillance of Chinese School Students in 2005 were enrolled in this study.We calculated the centile,means and standard deviations of waist and hip circumference and waist-to-hip ratio by age,gender,and its distribution pattern was compared with the American waist circumference charts of children and adolescents provided by American Center for Disease Control(CDC) from 1999 to 2002 and with the Beijing waist circumference charts of children and adolescents in 2004. Results The waist circumference was increasing with age in all samples and that was significantly higher in boys than that in girls(P0.01).The hip circumference was increasing with age in boys and that was significantly higher in girls than that in boys except the age group of 18 years(P0.01).The waist-to-hip ratio of boys was higher than that of girls(P0.01).Compared with the US CDC and Beijing waist circumference charts,P50 among the boys in Changsha was higher than Beijing's data but lower than US CDC's data with the same increasing tendency.However,P50 curve of girls in Changsha was smooth without sharp increase as compared with that of US CDC and Beijing. Conclusions There are gender and age differences of waist and hip circumference and waist-to-hip ratio,furthermore,there are geographical and race differences.This is the first time to study the waist and hip circumference and waist-tohip ratio of children and adolescents in the central south area.These data could be used for the clinical and epidemiological study of adolescent abdominal obesity.It is suggested that waist circumference should be measured in health examination of adolescents as a routine.It is useful for the following longitudinal study and the comparison between countries.