Arterial stiffness and osteoporosis in chronic obstructive pulmonary disease

Rationale: Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of cardiovascular events and osteoporosis. Increased arterial stiffness is an independent predictor of cardiovascular disease. Objectives: We tested the hypothesis that patients with COPD would have increased arterial stiffness, which would be associated with osteoporosis and systemic inflammation. Methods: We studied 75 clinically stable patients with a range of severity of airway obstruction and 42 healthy smoker or ex-smoker control subjects, free of cardiovascular disease. All subjects underwent spirometry, measurement of aortic pulse wave velocity (PWV) and augmentation index, dual-energy X-ray absorptiometry, and blood sampling for inflammatory mediators. Measurements and Main Results: Mean (SD) aortic PWV was greater in patients, 11.4 (2.7) m/s, than in control subjects, 8.95 (1.7) m/s, p < 0.0001. Inflammatory mediators and augmentation index were also greater in patients. Patients with osteoporosis at the hip had a greater aortic PWV, 13.1 (1.8) m/s, than those without, 11.2 (2.7) m/s, p < 0.05. In patients, aortic PWV was related to age (r = 0.63, p < 0.0001) and log(10) IL-6 (r = 0.31, p < 0.01), and inversely to FEV1 (r = -0.34, p < 0.01). The strongest predictors of aortic PWV in all subjects were age (p < 0.0001), percent predicted FEV1 (p < 0.05), mean arterial pressure (p < 0.05), and log(10) IL-6 (p < 0.05). Conclusions: Increased arterial stiffness was related to the severity of airflow obstruction and may be a factor in the excess risk for cardiovascular disease in COPD. The increased aortic PWV in patients with osteoporosis and the association with systemic inflammation suggest that age-related bone and vascular changes occur prematurely in COPD.