Peripheral endothelial function is positively associated with maximal aerobic capacity in patients with chronic obstructive pulmonary disease

Background: Patients with COPD are frequently diagnosed with cardiovascular disease. Peripheral endothelial dysfunction is an underlying mechanism and can be used as an early marker of cardiovascular impairment. To date, little is known on the association between peripheral endothelial dysfunction, cardiovascular risk factors and measurements of exercise capacity in patients with COPD. Therefore, we aimed to determine the relation between endothelial function and patient characteristics, cardiovascular risk factors and (micro)vascular and functional performance in patient with CODP.

Methods: Clinical and demographic data of patients with COPD were measured during routine pre-rehabilitation assessment. Cardiovascular risk factors, including blood pressure, ankle brachial index, arterial stiffness and retinal vessel widths were obtained. Peripheral endothelial function was measured using the EndoPAT-2000. Functional performance was assessed using cardiopulmonary exercise test, constant work rate test and six-minute walk test.

Results: 40 patients with COPD completed the study protocol (65% males; mean age: 62.8 +/- 7.3 years; mean FEV1: 45.8 +/- 17.5 %pred). Peripheral endothelial dysfunction was observed in 55% of the patients. Patients with peripheral endothelial dysfunction had significantly worse aerobic exercise capacity and higher prevalence of cardiovascular risk factors. Stepwise multivariate regression models identified sex, systolic blood pressure and maximal aerobic capacity as independent correlates of peripheral endothelial function. After correction for sex, age and systolic blood pressure, there was a significant partial correlation between peripheral endothelial function and maximal aerobic capacity (R = 0.51, p = 0.004).

Conclusion: Peripheral endothelial function was positively associated with maximal aerobic capacity, when correcting for sex, age and systolic blood pressure. Establishing peripheral endothelial dysfunction as a determinant of impaired aerobic capacity in COPD can be valuable for developing interventions aiming to improve aerobic capacity, and in turn cardiovascular health.