Background: The belief that weight loss improves obstructive sleep apnea (OSA) has limited empirical support. The purpose of this 4-center study was to assess the effects of weight loss on OSA over a 1-year period.
Methods: The study included 264 participants with type 2 diabetes and a mean (SD) age of 61.2 (6.5) years, weight of 102.4 (18.3) kg, body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) of 36.7 (5.7), and an apnea-hypopnea index (AHI) of 23.2 (16.5) events per hour. The participants were randomly assigned to either a behavioral weight loss program developed specifically for obese patients with type 2 diabetes (intensive lifestyle intervention [ILI]) or 3 group sessions related to effective diabetes management (diabetes support and education [DSE]).
Results: The ILI participants lost more weight at 1 year than did DSE participants (10.8 kg vs 0.6 kg; P < .001). Relative to the DSE group, the ILI intervention was associated with an adjusted (SE) decrease in AHI of 9.7 (2.0) events per hour (P < .001). At 1 year, more than 3 times as many participants in the ILI group than in the DSE group had total remission of their OSA, and the prevalence of severe OSA among ILI participants was half that of the DSE group. Initial AHI and weight loss were the strongest predictors of changes in AHI at 1 year (P < .01). Participants with a weight loss of 10 kg or more had the greatest reductions in AHI.
Conclusions: Physicians and their patients can expect that weight loss will result in significant and clinically relevant improvements in OSA among obese patients with type 2 diabetes. Trial Registration clinicaltrials.gov Identifier: NCT00194259.