Background/Objectives: There are controversies regarding the effect of obstructive sleep apnea (OSA) treatment with positive airway pressure (PAP) on diabetes-related outcomes. Therefore, we aimed to explore the association of PAP adherence with diabetes-related outcomes in patients with type 2 diabetes mellitus (T2DM) and OSA. Methods: In this prospective study, we included T2DM patients diagnosed with OSA during an 8-year period (2015-2023). PAP adherence (optimal usage for > 6 h/night for ≥ 70% of nights), hemoglobin A1c (HbA1c), body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP), daytime sleepiness (Epworth Sleepiness Scale-ESS) and cardiovascular (CVD) events were recorded. Comparisons of the change in diabetes-related outcomes (follow-up to baseline) in the adherent and non-adherent groups were assessed by analysis of covariance to adjust for relevant confounders. Results: Of the 355 patients included, 199 (56%) were PAP adherent. The mean follow-up period was 5.5 years. At the end of the follow up period, the PAP adherent group achieved a greater decrease in HbA1c levels (-1.4 vs. -0.3), SBP (-10.1 vs. -5.5), DBP (-2.9 vs. -0.55) and ESS (-5.9 vs. -4.2) compared to the non-adherent groups. Conclusions: Achieving optimal PAP adherence in patients with T2DM and OSA was associated with improved diabetes-related outcomes. Therefore, current practices need to be modified to incorporate systematic assessment and treatment of OSA in these patients.
Keywords: diabetes-related outcomes; obstructive sleep apnea; positive airway pressure; treatment adherence; type 2 diabetes mellitus.