Although obstructive sleep apnea (OSA) is associated with impaired glucose tolerance and diabetes, it remains unclear whether OSA treatment with continuous positive airway pressure (CPAP) has metabolic benefits. To determine the effect of 8-hour nightly CPAP treatment on glucose metabolism in individuals with prediabetes and OSA. In a randomized, controlled parallel group study, 39 participants were randomized (2:1) to receive either 8-hour nightly CPAP (n=26) or oral placebo (n=13). Sleep was polysomnographically recorded in the laboratory on each night. CPAP adherence was ensured by continuous supervision. Participants continued their daily daytime routine activities outside the laboratory. Glucose metabolism was assessed at baseline and after 2-weeks of assigned treatment using both the oral and intravenous glucose tolerance tests (OGTT and ivGTT, respectively). The primary outcome was the overall glucose response as quantified by the area under the curve for glucose during 2-hour oral glucose tolerance testing.
