COPD-sleep-disordered breathing overlap and vascular risk markers in non-obese adults: The Nagahama study

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea/sleep-disordered breathing (SDB) often coexist and may amplify vascular injury, yet the cardiovascular impact of COPD-SDB overlap in the absence of obesity remains unclear. We investigated whether overlap syndrome is associated with higher vascular markers than either condition alone. We also estimated its prevalence by obesity status.

In this population-based cohort, 9850 community residents were enrolled. Moderate-to-severe SDB was defined as an actigraphy-modified 3% oxygen desaturation index ≥15 events/h. COPD was defined as a smoking history of ≥10 pack-years and an FEV₁/FVC ratio <0.70. Overlap syndrome was defined as coexistence of COPD and moderate-to-severe SDB. Maximum common carotid artery intima-media thickness (CCA-IMT), cardio-ankle vascular index (CAVI), and brachial-ankle pulse wave velocity (baPWV) were assessed. Multivariable models were stratified by obesity.

A total of 6140 were analyzed. Overlap syndrome was identified in 46 participants (0.75%) overall, including 30 of 5087 non-obese participants (0.59%), and 16 of 1053 obese participants (1.52%). Because all overlap cases were male, subsequent adjusted analyses were restricted to men. Compared with moderate-to-severe SDB alone, overlap was associated with higher adjusted CCA-IMT in non-obese male participants. Overlap was also associated with higher CAVI and baPWV among non-obese men after multivariable adjustment.

COPD-moderate-to-severe SDB overlap was not negligible. Among non-obese men, overlap syndrome was associated with greater subclinical atherosclerosis and arterial stiffness than moderate-to-severe SDB alone, suggesting a higher vascular-risk phenotype.