Large Waist but Low Body Mass Index: The Metabolic Syndrome in Australian Aboriginal Children

ObjectiveTo describe the prevalence and clinical characteristics of the metabolic syndrome (MetS) in a cohort of Australian Aboriginal children.Study designBody mass index (BMI), waist circumference, skin fold thickness, body fat percentage, insulin resistance, and the prevalence of MetS were evaluated in 486 children age 9 to 14 years from the Darwin Health Region, Northern Territory, Australia.ResultsUsing an age- and sex- specific definition, 14% of the children in the cohort had MetS, 6.4% were overweight, 4.9% were obese, and 26.2% had an elevated waist circumference. The mean percentage of body fat was 30.2%. The children with MetS had higher BMI and waist z-scores, percent body fat, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) score, and skin fold thickness compared with those without MetS (P < .001); however, >50% of those with MetS were neither overweight nor obese. Waist circumference was significantly associated with insulin resistance as measured by the HOMA-IR (P < .001).ConclusionsMetS is common in our cohort despite low rates of overweight and obesity. A tendency for central adiposity is already evident in these young children. Measurement of waist circumference may help identify Aboriginal children at high risk for MetS.