Using anthropometric indices to predict cardio-metabolic risk factors in Australian indigenous populations.

AIMS: To compare the predictive power of anthropometric indices (BMI, waist circumference (WC), waist-to-hip ratio (WHpR) and waist-to-height ratio (WHtR)) for diabetes, hypertension and dyslipidemia in Australian Aboriginal and Torres Strait Islander (TSI) adults.

METHODS: Cross-sectional study of 2862 Indigenous Australians aged over 15 living in rural communities in Far North Queensland during 1999-2001. The predictive values of anthropometric indices for cardio-metabolic disorders were compared using receiver operating characteristic (ROC) analysis.

RESULTS: BMI was the poorest predictor while WHpR was the best among the four measures. The optimal WHtR and WHpR cut-off points for the cardio-metabolic risks in both women and men in the two Indigenous populations were 0.5-0.6 and 0.9 respectively. Optimal BMI cut-offs for diabetes, hypertension, and dyslipidemia were much lower in Aborigines than the recommended WHO BMI cut-offs, while those in TSIs were around WHO BMI criteria. The optimal WC cut-points varied by gender and ethnicity.

CONCLUSIONS: BMI was not a good discriminator of cardio-metabolic risk factors in Australian Indigenous populations compared with other anthropometric indices. WHpR is more closely associated with the risk of cardio-metabolic in these high-risk populations.