Sleep Architecture Following a Weight Loss Intervention in Overweight and Obese Patients with Obstructive Sleep Apnea and Type 2 Diabetes: Relationship to Apnea-Hypopnea Index

Study Objectives: To determine if weight loss and/or changes in apnea-hypopnea index (AHI) improve sleep architecture in overweight/obese adults with type 2 diabetes (T2D) and obstructive sleep apnea (OSA). Methods: This was a randomized controlled trial including 264 overweight/obese adults with T2D and OSA. Participants were randomized to an intensive lifestyle intervention (ILI) or a diabetes and support education (DSE) control group. Measures included anthropometry, AHI, and sleep at baseline and year-1, year-2, and year-4 follow-ups. Results: Changes in sleep duration (total sleep time [TST]), continuity [wake after sleep onset (WASO)], and architecture stage 1, stage 2, slow wave sleep, and REM sleep) from baseline to year 1, 2, and 4 did not differ between ILI and DSE. Repeated-measure mixed-model analyses including data from baseline through year-4 for all participants demonstrated a significant positive association between AHI and stage 1 sleep (p < 0.001), and a significant negative association between AHI and stage 2 (p = 0.01) and REM sleep (p < 0.001), whereas changes in body weight had no relation to any sleep stages or TST. WASO had a significant positive association with change in body weight (p = 0.009). Conclusions: Compared to control, the ILI did not induce significant changes in sleep across the 4-year follow-up. In participants overall, reduced AHI in overweight/obese adults with T2D and OSA was associated with decreased stage 1, and increased stage 2 and REM sleep. These sleep architecture changes are more strongly related to reductions in AHI than body weight, whereas WASO may be more influenced by weight than AHI.