Waist circumference percentiles in 2-18 year old Indian children.

Objectives: To develop reference percentile curves in Indian children for waist circumference (WC), and to provide a cutoff of WC percentile to identify children at risk for metabolic syndrome (MS).

Study Design: A multicenter, cross-sectional study was performed in 5 major Indian cities. Height, weight, and blood pressure (BP) were measured in 10,842 children (6065 boys). Elevated BP was defined as either systolic BP or diastolic BP >95th percentile. WC was measured with the child standing using a stretch-resistant tape. Sex-specific reference percentiles were computed using the LMS method which constructs reference percentiles adjusted for skewness. To determine optimal cutoffs for WC percentiles, a validation sample of 208 children was assessed for MS risk factors (ie, anthropometry, BP, blood lipids), and receiver operating characteristic (ROC) curve analysis was performed.

Results: Age- and sex-specific WC percentiles (5th, 10th, 15th, 25th, 50th, 75th, 85th, 90th, and 95th) are presented. WC values increased with age in both the boys and the girls. The median WC at age >15 years was greater in boys compared with girls. ROC analysis suggested the 70th percentile as a cutoff for MS risk (sensitivity, 0.84 in boys and 0.82 in girls; specificity, 0.85 in both boys and girls; area under the ROC curve, 0.88 in boys and 0.92 in girls).

Conclusion: Age- and sex-specific reference curves for WC for Indian children and cutoff values of 70th WC percentile for screening for MS risk are provided.