Waist Circumference Cutoff Point Determination for Defining Metabolic Syndrome in Type 2 Diabetes Mellitus in Ethiopia

BACKGROUND: Metabolic syndrome (MetS) is a complex disorder characterized by a cluster of interrelated cardiovascular risk factors. So far, cutoff point variability of waist circumference was documented to define MetS. OBJECTIVE: To determine the classification power and cutoff point of waist circumference to define MetS among patients with type 2 diabetes. METHODS: An institution-based cross sectional study was conducted from March to April 2017 at Ayder Comprehensive Specialized Hospital among patients with type 2 diabetes. Using systematic sampling technique, 520 participants were enrolled into the study. Data were collected by checklist, anthropometric measurements and biochemical analyses. Data were entered to Epi-info 3.5.1 and transferred to SPSS 20 for analysis. Participants having more than one abnormal MetS components were categorized as patients and the others were considered as control. The classification power of waist circumference to distinguish patients from controls was determined by ROC curve analysis. Waist circumference cutoff points were determined by taking the point that had a maximum youden index. RESULTS: Among the 520 participants, 308 (59.2%) were females. The mean age of the participants was 56 ± 10.8 years for males and 55 ± 11.4 years for females. The classification power of waist circumference was 0.67 (0.58-0.75) for male and 0.63 (0.52-0.73) for females. The optimal waist circumference cutoff point to distinguish patients from controls were 95.5 cm (sensitivity 39.8%, specificity 86.3%, p< 0.001) for males, and 87.5 cm (sensitivity 73.1%, specificity 54.5%, p< 0.017) for females. CONCLUSION: The positive predictive value of waist circumference was 93% for females and 90% for males in Northern Ethiopia using 87.5 and 95.5 cm points cut-off for females and males, respectively.