Comparison of different anthropometric indices for identifying insulin resistance in schoolchildren.

OBJECTIVES: Anthropometric indices have been associated with insulin resistance in children. This study (1) determined the association between insulin resistance and anthropometric indices, including body mass index (BMI), waist circumference (WC), WC/height, weight/(sitting height)(2), and WC/sitting height, and (2) compared the abilities of these five indices to identify children with insulin resistance.

METHODS: Data were collected from six elementary schools in Argentina between April and August 2007. Anthropometric data and Tanner staging were obtained. Fasting serum concentrations of glucose, lipids, and insulin were measured.

RESULTS: Six hundred twenty-five children (318 boys) between 6 and 14 years old were examined. The mean age of the children was 9.6 +/- 2.0 years. Ninety-six (15.4%) of the children were obese, 91 (14.6%) were overweight, and 438 (70.1%) were normal weight using Centers for Disease Control and Prevention norms. Sixty percent, 23.0%, 14.0%, and 3.0% were Tanner stage I, II, III, and IV, respectively. The areas under the receiver operator characteristic curves were as follows: WC = 0.78 +/- 0.021 (95% confidence interval [CI] 0.74-0.82), BMI = 0.77 +/- 0.022 (95% CI 0.73-0.82), weight/(sitting height)(2) = 0.76 +/- 0.022 (95% CI 0.72-0.81), WC/height = 0.67 +/- 0.027 (95% CI 0.62-0.72), and WC/sitting height = 0.67 +/- 0.27 (95% CI 0.62-0.72), indicating that BMI, WC, and weight/(sitting height)(2) were acceptable predictors for insulin resistance, whereas WC/height and WC/sitting height were fair predictors as the areas under the curve were <0.7.

CONCLUSIONS: This study suggests that WC and BMI are (and remain) the best correlates for insulin resistance. In contrast, the indices of the ratio between WC and height were fair predictors for insulin resistance. Additional longitudinal studies should be done to further confirm these findings.