Researchers in the United Kingdom have found that patients with COPD, or chronic obstructive pulmonary disease, have greater arterial stiffness.
The researchers also found that those COPD patients with osteoporosis, a common complication of the respiratory disease, had even greater arterial stiffness. These premature signs of aging may explain why COPD patients are at greater risk for cardiovascular disease.
Their research results appear in the second issue for June 2007 of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
Dennis J. Shale, M.D., of the Department of Respiratory Medicine at Cardiff University in the United Kingdom, and eight associates studied 75 clinically stable COPD patients who had various levels of airway obstruction, and 42 smoker or ex-smoker control subjects who did not have cardiovascular disease or COPD.
COPD involves persistent obstruction of the airways caused by emphysema or chronic bronchitis. In most instances, both conditions result from years of smoking cigarettes. COPD is expected to become the third most common cause of death worldwide by 2020, according to the study authors.
Though the exact link between COPD and atherosclerosis was not identified by the researchers, they did find elevated levels of inflammation markers in those with COPD. Other research has demonstrated that inflammatory processes are involved in all stages of atherosclerosis, and there is also evidence that inflammation has a role in osteoporosis.
All participants in the U.K. study underwent spirometry to determine lung function, had their aortic pulse wave velocity measured along with another indirect measurement of arterial stiffness, took bone mineral density tests of their spine and hips, and had their blood sampled for inflammatory mediators.
"Increased arterial stiffness was present in patients with COPD over a wide range of severity of airway obstruction and was greatest in those with osteoporosis," said Dr. Shale. "Our findings indicate vascular changes predictive of cardiovascular disease occur and remain undetected in mild or early lung disease and may underlie the excess cardiovascular risk in COPD."
The researchers noted that age was an important factor influencing arterial stiffness, a problem that reflects the increasing rigidity of the aortic artery. The average age of the study cohort was 63.
"The increased arterial stiffness in patients within each decade is similar to changes seen in type I diabetes mellitus and suggest that age-related vascular changes occur prematurely in COPD, as compared with disease-free individuals," said Dr. Shale. "However, unlike diabetes mellitus, the risk of premature excess cardiovascular disease in COPD is not appreciated."
At the beginning of the study, none of the participants had a history of heart disease or possessed cardiovascular symptoms. Of the 75 COPD patients studied, 18 had osteoporosis, while among the controls, only two individuals suffered from abnormal loss of bony tissue. Also, those who had osteoporosis of the hip had a greater aortic pulse wave velocity than those without the hip problem.