Determinants of systemic vascular function in patients with stable chronic obstructive pulmonary disease

Abstract

Rationale: Impaired vascular reactivity is an important factor in the pathogenesis of cardiovascular disease.

Objectives: We sought to assess vascular reactivity in patients with chronic obstructive pulmonary disease (COPD) and respective control subjects, and to investigate the relation between vascular function and airflow obstruction and systemic inflammation.

Methods: We studied 60 patients with stable COPD; 20 smokers with normal lung function matched for age, sex, and body weight; and 20 similarly matched nonsmokers. Patients with cardiovascular comorbidities were excluded. The endothelium-dependent and endothelium-independent function of the vasculature was measured using flow-mediated and nitrogen-mediated dilation of the brachial artery, respectively. Systemic inflammatory markers, including C-reactive protein, fibrinogen, and interleukin (IL)-6, were determined in serum.

Measurements and main results: Both flow-mediated and nitrogen-mediated dilation of the brachial artery were significantly lower in patients with stable COPD than in smoking and nonsmoking control subjects. Levels of inflammatory mediators such as IL-6 and fibrinogen were higher in patients than they were in control subjects. In patients with COPD, stepwise multiple regression analysis showed that age, sex, baseline brachial artery diameter, C-reactive protein level, leukocyte count, blood glucose level, and percentage of predicted forced expiratory volume in 1 s were independent predictors of flow-mediated dilation. There was no relation between flow-mediated dilation and pack-years of smoking. Baseline brachial artery diameter was the only independent predictor of nitrogen-mediated dilation in patients with COPD.

Conclusions: Both endothelium-dependent and endothelium-independent vasodilation is significantly impaired in patients with stable COPD. Airflow obstruction and systemic inflammation may increase the risk of cardiovascular disease in patients with COPD.