Relationships between BMI, waist circumference, hypertension and fasting glucose: Rethinking risk factors in Indigenous diabetes

摘要

ududTo determine whether the body mass index (BMI) threshold defined for obesity (30kg/m2) adequately reflects risk in an Aboriginal community with a high rate of Type 2 diabetes. ududududData about five diabetes risk factors (age, BMI, waist circumference (WC), hypertension and family history) and fasting glucose (FG) were obtained from a random sample of 117 Aboriginal adults (62 women and 55 men) never diagnosed with diabetes. Linear regression between BMI, WC and FG, and sensitivity and specificity analyses in predicting elevated FG and hypertension were conducted.ududududBMI≥30kg/m2 and central obesity assessed by WC (women≥88cm;udmen≥102cm) were strongly and positively associated. Among women, central obesity was near universal, occurring at BMIs below the ‘healthy’ range of 20-25. WC was linearly associated with other diabetes risk factors. WC≥88cm was more sensitive but less specific than BMI≥30 in predicting elevated FG and hypertension among women, while BMI≥25 among men tended to be both more sensitive and more specific than both BMI≥30 and WC≥102cm.ududududIn women, central obesity is a better predictor of diabetes and CVD risk than BMI≥30, which is not a reliable indicator. BMI≥25 was a good predictor in men.udImplications: BMI is a useful clinical tool to identify individuals at risk, but to be relevant the guidelines defining risk may need to be reduced for the Aboriginal population. For women, a BMI≥25 could more adequately reflect risk, while the current WC of 88cm remains appropriate. For men, a reduction in both BMI to ≥25 and WC to 90cm may better reflect diabetes and CVD risk.