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 >= 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 0.59 had significantly higher age and sociodemographic multivariable-adjusted odds ratios for cardiometabolic risk factors than subjects with WHtR <05.9, 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.