Waist circumference and waist for height percentiles in urban South Indian children aged 3-16 years.

OBJECTIVES To develop age and gender specific waist circumference references for urban Indian children aged 3 -16 years. DESIGN Cross-sectional study. SETTING Urban preschools and schools of Bangalore. PARTICIPANTS 9060 children (5172 boys and 3888 girls) in the age group of 3-16 years. METHODS Weight, height, and waist circumference were measured using standard anthropometric methodology. Percentiles for waist circumference and Waist/height ratio (W/Ht) for each age and gender were constructed and smoothed using the LMS method. RESULTS Mean waist circumference increased with age for both girls and boys. The upper end of curve in boys continued to increase, whereas in the girls it tended to plateau at 14 years. The waist circumference of the Indian children from the present study was higher than age and sex matched European children. The proportion of children with W/Ht ratio greater than 0.5 decreased as their age increased. CONCLUSIONS These curves represent the first waist and waist height ratio percentiles for Indian children and could be used as reference values for urban Indian children. We suggest that for a start, the 75th percentile of waist circumference from this study be used as an action point for Indian children to identify obesity (as a tautological argument), while retaining the cut-off of 0.5 for the W/Ht ratio; however this underlines the need to derive biologically rational cut-offs that would relate to different levels of risk for adult cardiovascular disease.