Optimal BMI cut-off values for predicting diabetes, hypertension and hypercholesterolaemia in a multi-ethnic population.

OBJECTIVE To determine the optimal cut-offs of BMI for Malaysian adults. DESIGN Population-based, cross-sectional study. Receiver operating characteristic curves were used to determine the cut-off values of BMI with optimum sensitivity and specificity for the detection of three cardiovascular risk factors: diabetes mellitus, hypertension and hypercholesterolaemia. Gender-specific logistic regression analyses were used to examine the association between BMI and these cardiovascular risk factors. SETTING All fourteen states in Malaysia. SUBJECTS Malaysian adults aged ≥18 years (n 32 703) who participated in the Third National Health and Morbidity Survey in 2006. RESULTS The optimal BMI cut-off value for predicting the presence of diabetes mellitus, hypertension, hypercholesterolaemia or at least one of these cardiovascular risk factors varied from 23.3 to 24.1 kg/m2 for men and from 24.0 to 25.4 kg/m2 for women. In men and women, the odds ratio for having diabetes mellitus, hypertension, hypercholesterolaemia or at least one cardiovascular risk factor increased significantly as BMI cut-off point increased. CONCLUSIONS Our findings indicate that BMI cut-offs of 23.0 kg/m2 in men and 24.0 kg/m2 in women are appropriate for classification of overweight. We suggest that these cut-offs can be used by health professionals to identify individuals for cardiovascular risk screening and weight management programmes.