Developing waist circumference, waist-to-height ratio percentile curves for Pakistani children and adolescents aged 2-18 years using Lambda-Mu-Sigma (LMS) method.

Objectives Children from different countries and with different ethnic backgrounds have a distinct pattern of central fat deposition. Therefore, it is essential to develop population-specific percentiles of waist circumference (WC), waist-to-height ratio (WHtR) and waist-to-height ratio exponent (WHtR (exp)) for the evaluation of central obesity. The objective of this study was to develop age-and-gender-specific smoothed WC and WHtR percentile curves for the Pakistani children and adolescents aged 2-18 years. Methods A cross-sectional data-set from a multi-ethnic anthropometric survey was considered. A sample of 10,668 healthy subjects (boys = 51.92%; and girls = 48.08%), aged 2-18 years was studied. Height (cm) and WC (cm) of each subject was measured under standard procedure and WHtR & WHtR (exp) were calculated. Age-and-gender-specific smoothed curves were obtained using the lambda-mu-sigma (LMS) method and compared with percentile curves obtained from different countries. Results Except few early ages, the WC values increased with age in both sexes. Both boys and girls had approximately similar WC during 6-11 years of age and after age of 11, the boys had larger WC than the girls had. For WHtR, the centile curves showed a continuous decrease by 16 years of age and then increased gradually. WHtR of the girls in various ages were having similar or higher than those of the boys. In comparison of WC 50th and 90th percentiles with other countries, it was found that except few ages, the Pakistani children had larger WC than the other reference populations and the results of WHtR were also comparable to the other nations. Conclusions We present new reference data of WC, WHtR and WHtR (exp) using a representative sample of the Pakistani children aged 2-18 years. These reference values can be used provisionally for early detection of central obesity and its associated risks in the Pakistani children.