Obesity and Body Fat Distribution as Predictors for Obstructive Sleep Apnea Syndrome

Background: Analysis of correlation between obesity surrogates and body fat distribution in individuals with suspicion of obstructive sleep apnea syndrome (OSAS) from "Victor Babes Hospital", Timisoara, Romania. Materials and Methods: We evaluated with polysomnography (PSG) 1277 consecutive patients referred with suspected OSAS, performing anthropological measurements, together with weight in kilograms divided by the square of height in meters (body - mass index BMI), circumference of the neck in centimetres (NC), circumference of abdomen in centimeter (AC), and the ratio of the circumference of the waist to that of the hips (waist-hip ratio W/HR). Multiple linear regression analysis with stepwise regression model used apnea - hypopnea index (AHI) as a dependent variable and variables of interest as independent variables. Results: 797 of the patients (62.41%) had obesity (with a median age 54 years), 480 patients (37.59%) presented normal BMI (median age 52). Obese subjects had significantly higher AHI: 41.25/h (25.5 - 61.3) vs 26.8/h (15.3 - 39.9) (p<0.001). Age (beta=0.191, p<0.001) and W/HR (beta=0.104, p=0.043) at females and AC (beta=0.16, p=0.025) at males have a higher influence on AHI. AHI has a positive correlation with NC (r =0.389, p <0.001) and AC (r =0.371, p <0.001). The risk of OSAS is 7.7 higher for obese female vs normal weight (OR=7.74, 95% CI 3.52-17.02) and 6.1 higher for obese male vs normal weight (OR=6.12, 95% CI 2.66-14.1), with no significant difference between genres (Breslow-Days Test, p=0.69). Snoring had a 7.51 increased risk of having OSAS (OR=7.51, 95% CI 4.29-13.15). Conclusion: Obesity surrogates and body fat distribution are strongly correlated with AHI. Obese females have a higher risk of OSAS. The most powerful predictor for OSAS was active smoking. Associated snoring is the most powerful predictor for OSAS.