Continuous Positive Airway Pressure Treatment for Obstructive Sleep Apnea Does Not Reduce Arterial Stiffness in Patients With Type 2 Diabetes After One Year of Follow-Up

Background: The aim of this study is to evaluate the effects of 12-month continuous positive airway pressure (CPAP) treatment on arterial stiffness in patients with type 2 diabetes. Methods: Obstructive sleep apnea (OSA) and type 2 diabetes frequently co-exists. Both diseases increase arterial stiffness, a marker of cardiovascular risk. Treating OSA with CPAP may lower arterial stiffness. In a recent randomized trial, we found that CPAP treatment for 12 weeks did not reduce arterial stiffness in type 2 diabetes patients with OSA. Participants from the randomized trial were invited to a follow-up study 12 months after inclusion. We evaluated arterial stiffness by measuring carotid-femoral pulse wave velocity (cfPWV) using SphygmoCor. Results: Forty-six patients (63.9% of the original 72 patients, age 63.8 +/- 6.5 years, diabetes duration 16.1 +/- 9.7 years, body mass index (BMI) 34.7 +/- 3.9 kg/m 2 ) partook in the study. Mean duration of CPAP treatment was 10.5 +/- 1.5 months. Baseline cfPWV was 10.7 in/s. At follow-up cfPWV was 10.6 m/s, change in cfPWV: -0.12 m/s, 95% confidence interval (CI): -0.6, 0.4, P = 0.6. Baseline systolic blood pressure (BP) was 136.2 mm Hg. At follow-up BP was 137.9 min Hg, change in BP: 1.6 nun Hg, 95% CI: -2.3, 5.5. Conclusions: We found no effect of 9 - 12-month CPAP treatment on arterial stiffness or BP in patients with long duration of type 2 diabetes and OSA.