Is obstructive sleep apnea associated with increased arterial stiffness in patients with COPD?

PURPOSE: To evaluate arterial stiffness, a predictor of vascular damage was assessed by means of pulse wave velocity (PWV) in patients with chronic obstructive pulmonary disease (COPD) and comorbid obstructive sleep apnea (OSA), namely overlap syndrome (OS). METHODS: Consecutive stable patients with COPD were evaluated for OSA by means of overnight polysomnography in the laboratory. A clinical assessment was performed according to a strict protocol, including two COPD questionnaires: the COPD assessment test and the modified Medical Research Council scale. COPD severity was graded according to the guidelines of the Global Initiative for Chronic Obstructive Lung Disease. Arterial stiffness was assessed by means of PWV, using a standard technique. RESULTS: Of 102 patients with COPD, 51 had associated OSA. The OS group had more men than the COPD group (73% vs. 47%, respectively; p < 0.01). Both groups had similar ages (66.2 ± 9.2 years vs. 69.6 ± 10.7, p = 0.09) and airflow limitation (p = 0.37). Hypertension was found in 22% of COPD patients, as opposed to 17% patients in the OS group (p = 0.29). High PWV values were present in 42% of the patients. Patients with COPD and OS had the same PWV values (9.8 vs. 10.5 m/s, p = 0.34). There were no differences in central blood pressure, peripheral blood pressure, and augmentation index between the two groups (p > 0.05). CONCLUSION: High PWV values were frequently observed in patients with COPD. However, there was no difference in PWV between patients with OS and those with COPD alone.