Impact of obstructive sleep apnea on metabolic dysfunction in severe obesity.

Obstructive Sleep Apnoea (OSA) seems to worsen metabolism. This effect has not evaluated in morbid obesity (MO). We hypothesized that the metabolic profile is more impaired in MO patients with OSA than in those without and investigated whether any specific metabolic dysfunction is related to OSA in MO. A prospective multi-centre cross-sectional study was conducted in consecutive subjects before bariatric surgery. OSA was defined as apnoea-hypopnoea index (AHI)≥15 by overnight polysomnography (PSG). Anthropometrical, blood pressure (BP) and fasting blood measurements were obtained the morning after. Metabolic Syndrome (MetS) was defined according to NCEP ATPIII modified criteria. 159 patients were studied: 72% female, 72% OSA. MetS prevalence was 70% in OSA vs 36% in non-OSA (p<0.001). As AHI severity increased, metabolic parameters progressively worsened, even in those without type 2 diabetes (DM2). AHI was independently associated with systolic and diastolic BP, TG and HbA1c in the total sample and with systolic BP, cHDL and HbA1c in those without DM2. OSA increased the adjusted odds ratio of having MetS by 2.8 (95%CI 1.3-6.2, p 0.009). In MO, OSA is associated with major metabolic impairment caused by higher BP and poorer lipid and glucose control, independent of central obesity or DM2.