Aortic calcification, arterial stiffness and bone mineral density in patients with COPD

Background: Increased arterial stiffness, using aortic pulse wave velocity (PWV) has been demonstrated in patients with COPD. However, mechanisms underlying this remain unclear. We explored the contribution of aortic calcification to large artery haemodynamics and its association to bone mineral density (BMD) in patients with confirmed COPD. Methods: Patients with COPD, free of maintenance oral corticosteroids, renal disease, diabetes or known cardiovascular disease (n = 45), 27 male, mean (SD) age 66(7) years underwent unenhanced thoraco-abdominal computed tomography to determine quantitative aortic calcium content using a volume scoring method. Aortic PWV was measured. A subgroup (n = 29) had BMD determined. Results: All patients had some evidence of aortic calcification. Aortic PWV was related to log₁₀ calcification in abdominal aorta (r = 0.34, p = 0.025) and to semi-quantitative assessment in the ascending and descending thoracic aorta (r = 0.47 and r = 0.39, both p < 0.01). Log₁₀ calcium was inversely related to BMD hip (r = -0.43), p = 0.02. Both aortic PWV and log₁₀ calcium were related to age, which on multiple regression was the independent variable. Conclusions: Aortic calcification is related to aortic stiffness, an independent predictor of cardiovascular mortality and morbidity, and inversely to BMD in patients with COPD. Given, both cardiovascular disease and osteoporosis are common in patients with COPD, determining underlying mechanisms are essential as potential therapeutic targets.