OBJECTIVE: Obesity is considered a major risk factor for obstructive sleep apnea syndrome (OSAS). This study aimed to examine the correlation between anthropometric measurements, which have been recently defined and are indicative of abdominal obesity and cardiometabolic diseases, OSAS severity, and polysomnography (PSG) parameters in patients with OSAS.MATERIAL AND METHODS: This retrospective cohort study included patients who underwent all-night polysomnography with a prediagnosis of OSAS. These patients were categorized as having mild (5-15), moderate (15-30), and severe (>30) OSAS according to the apnea-hypopnea index (AHI). The anthropometric measurements used in the study consisted of waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), (waist/hip)-to-height ratio (WHHR), a body shape index (ABSI), body adiposity index (BAI), abdominal volume index (AVI), and conicity index (CI).RESULTS: A total of 410 individuals were enrolled in the study (31 control subjects and 129 with mild, 101 with moderate, and 149 with severe OSAS). A significant difference was observed between groups in terms of all anthropometric measurements (p<0.05). The difference between the groups was significant in terms of diabetes mellitus, hypertension, and cardiovascular disease (p<0.05). There was a significant correlation between each of the anthropometric measurements and the PSG parameters. In the receiver operating characteristic analysis, cutoff values that predicted severe OSAS were ABSI>0.08, BAI>28.29, AVI>25.54, and CI>1.37. Multiple regression analyses demonstrated that age, sex, and AVI were independent predictors that determine OSAS presence.CONCLUSION: Anthropometric parameters that are indicators of abdominal obesity were found to be robustly correlated with cardiometabolic diseases and the severity of OSAS.