Obstructive Sleep Apnea Is Independently Associated with the Metabolic Syndrome in Obese Asian Indians in Northern India

Abstract

Obesity and the metabolic syndrome are rapidly increasing in developing countries. Whether the metabolic syndrome is independently associated with obstructive sleep apnea (OSA) is not clear. This study investigated the association between OSA and the metabolic syndrome in obese Asian Indians. We studied 240 obese subjects [body mass index (BMI) >25 kg/m2], 121 with OSA and 119 without OSA, matched for age, BMI, and percentage body fat (%BF). Full-montage digital polysomnography, fasting blood glucose (FBG), lipid levels, and blood pressure (BP) were done in all subjects. Subjects with OSA showed higher prevalence of the metabolic syndrome as compared to subjects without OSA [67.8% vs. 42.02%; χ2 = 16.08, P < 0.0001, odds ratio (OR) = 2.90, 95% confidence interval (CI)]. Prevalence of the metabolic syndrome was significantly higher in the severe OSA group as compared to the moderate OSA group (78.7% vs. 40.9%; χ2 = 11.57; P < 0.001; OR = 0.19, 95% CI). Fasting insulin levels were significantly higher in subjects with OSA as compared to subjects without OSA [median (range); 84.03(12.5-541.7) pmol/L vs. 64.4(10.4-520.8) pmol/L; P = 0.002)]. Regression analysis suggested that OSA was independently and positively associated with the metabolic syndrome, male gender, and fasting insulin levels. OSA is independently associated with the metabolic syndrome in Asian Indians in northern India.