[Distribution of waist circumference and waist-to-height ratio and their values in obesity screening among 3-9 years old Han and Uygur ethnic children in Xinjiang Uygur Autonomous Region of China].

Objective: To understand the distributions of waist circumference and waist-to-height ratio (WHtR) in Han and Uygur ethnic children aged 3-9 years in Xinjiang Uygur Autonomous Region (Xinjiang) and discuss their values in obesity screening in children.
Methods: Stratified cluster random sampling was conducted to select Han and Uygur ethnic children from kindergartens and primary schools in four areas of Xinjiang in April 2014. The children's standing height, body weight and waist circumference were measured by trained investigators according to standard protocol. WC>or=P80 and WHtR>or=0.48 were used as the cutoff value for abdominal obesity screening in children with normal BMI. The association between overweight/obese prevalence rate and obesity related indicators, such as BMI, WC, WHtR, were analyzed.
Results: A total of 4024 Han and Uygur ethnic children were investigated, in which 2461 were in Han ethnic group, 1563 were in Uygur ethnic group. The WC and WHtR at P50 and P80 were differed significantly. In both Han and Uygur ethnic groups, there were some children with WC>or=P80 or WHtR>or=0.48, although they had normal BMI. This proportion decreased with age.
Conclusions: The WC and WHtR are similar in Han and Uygur ethnic children aged 3-9 years. WC and WHtR have values in obesity screening for children with normal BMI which suggested to use it as the supplementation of BMI in obesity screening in preschool aged children.