Optimal waist:height ratio cut-off point for cardiometabolic risk factors in Turkish adults

OBJECTIVE: To identify the optimal waist:height ratio (WHtR) cut-off point that discriminates cardiometabolic risk factors in Turkish adults. DESIGN: Cross-sectional study. Hypertension, dyslipidaemia, diabetes, metabolic syndrome score >or=2 (presence of two or more metabolic syndrome components except for waist circumference) and at least one risk factor (diabetes, hypertension or dyslipidaemia) were categorical outcome variables. Receiver-operating characteristic (ROC) curves were prepared by plotting 1 - specificity on the x-axis and sensitivity on the y-axis. The WHtR value that had the highest Youden index was selected as the optimal cut-off point for each cardiometabolic risk factor (Youden index = sensitivity + specificity - 1). SETTING: Turkey, 2003. SUBJECTS: Adults (1121 women and 571 men) aged 18 years and over were examined. RESULTS: Analysis of ROC coordinate tables showed that the optimal cut-off value ranged between 0.55 and 0.60 and was almost equal between men and women. The sensitivities of the identified cut-offs were between 0.63 and 0.81, the specificities were between 0.42 and 0.71 and the accuracies were between 0.65 and 0.73, for men and women. The cut-off point of 0.59 was the most frequently identified value for discrimination of the studied cardiometabolic risk factors. Subjects classified as having WHtR >or= 0.59 had significantly higher age and sociodemographic multivariable-adjusted odds ratios for cardiometabolic risk factors than subjects with WHtR < 0.59, except for diabetes in men. CONCLUSIONS: We show that the optimal WHtR cut-off point to discriminate cardiometabolic risk factors is 0.59 in Turkish adults.