Waist circumference distribution of Chinese school-age children and adolescents / 中华流行病学杂志

ABSTRACT

Objective To study the distribution of waist circumference (WC) in a representative group of Chinese children for establishing the Chinese WC cut-off points. Methods Cross-sectional data obtained from 15 mainland provinces and Hong Kong were collected. There were 178 865 children and adolescents, aged 7-18 years-old in total. All subjects were divided into five regional groups- costal city, non-coastal city, northern rural, southern rural, and Hong Kong, for analyzing the distribution of WC. Results Large variations in WC distribution were found among the five groups for both sexes. The coastal city group had the highest P85 WC values consistently from the early school age to 18-year-old, when comparing with other groups. In contrast, southern rural group had P85 values consistently lagged behind, in both city group and in the north rural group. Hong Kong group had a high P85 WC at early ages, but because of the smaller increments of WC during adolescence, the P85 curve was gradually exceeded by the northern rural groups. Catch-up trend was found in the two rural groups since peak puberty. These disparities were caused not only by factors related to socioeconomic and urban-rural but also to the geographic differences between the noah and the south. Because of the regional variation of WC, a "gradient" prevalence of central obesity was prospected among these groups. Closed associations were found between WC and height, weight and BMI in all age period. Comparison on the WC distributions between people from China, U.S.A or the Netherlands demonstrated the necessity of setting up China's own WC cutoffs.Sex and age-specific percentiles were obtained and smoothed by using the LMS method.Conclusion Data obtained from this study could be used to develop the national WC cutoff points for Chinese children and adolescents.