Eight Hours of Nightly Continuous Positive Airway Pressure Treatment of Obstructive Sleep Apnea Improves Glucose Metabolism in Patients with Prediabetes. A Randomized Controlled Trial

Rationale: 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.Objectives: To determine the effect of 8-hour nightly CPAP treatment on glucose metabolism in individuals with prediabetes and OSA.Methods: In a randomized controlled parallel group study, 39 participants were randomly assigned 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 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. The primary outcome was the overall glucose response as quantified by the area under the curve for glucose during 2-hour oral glucose tolerance tes...