Does CPAP Improve Glycemic Control in Patients with Diabetes and Sleep Apnea?

In the randomized SAVE trial, which included 2700 patients with moderate-to-severe obstructive sleep apnea (OSA) and histories of cardiovascular disease, continuous positive airway pressure (CPAP) did not lower incidence of adverse cardiovascular events compared with usual care (NEJM JW Gen Med Oct 1 2016 and N Engl J Med 2016; 375:919). During the trial's average follow-up of nearly 4 years, diabetes was newly diagnosed in ≈5% of patients in both the CPAP and control groups. In this substudy of the SAVE trial, researchers examined glycemia outcomes in patients with diabetes or prediabetes at baseline.

Among 274 patients with preexisting diabetes, fasting blood glucose and glycosylated hemoglobin (HbA_1c) levels did not differ significantly b…