Association of continuous positive airway pressure adherence with complications in patients with type 2 diabetes and obstructive sleep apnea

Study Objectives: To explore the association of continuous positive airway pressure (CPAP) adherence with clinical outcomes in patients with type 2 diabetes and obstructive sleep apnea in a real-world setting. Methods: This was a retrospective study of patients with type 2 diabetes diagnosed with obstructive sleep apnea between 2010 and 2017. CPAP adherence (usage for >= 4 h/night for >= 70% of nights) was determined from the first CPAP report following the polysomnography. Data including estimated glomerular filtration rate, hemoglobin A1c, systolic and diastolic blood pressure, lipid panel, and incident cardiovascular/peripheral vascular/cerebrovascular events were extracted from medical records. Mixed-effects linear regression modeling of longitudinal repeated measures within patients was utilized for continuous outcomes, and logistic regression modeling was used for binary outcomes. Models were controlled for age, sex, body mass index, medications, and baseline levels of outcomes. Results: Of the 1,295 patients, 260 (20.7%) were CPAP adherent, 318 (24.5%) were CPAP nonadherent, and 717 (55.3%) had insufficient data. The follow-up period was, on average, 2.5 (1.7) years. Compared to those who were CPAP nonadherent, those who were adherent had a significantly lower systolic blood pressure (beta = -1.95mm Hg, P = .001) and diastolic blood pressure (beta = -2.33mm Hg, P < .0001). Among the patients who were CPAP adherent, a 17% greater CPAP adherence was associated with a 2 mm Hg lower systolic blood pressure. Lipids, hemoglobin A1c, estimated glomerular filtration rate, and incident cardiovascular/peripheral vascular/cerebrovascular events were not different between the 2 groups. Conclusions: Achieving CPAP adherence in patients with type 2 diabetes and obstructive sleep apnea was associated with significantly lower blood pressure. Greater CPAP use within patients who were adherent was associated with lower systolic blood pressure.