Patients with chronic obstructive pulmonary disease (COPD) have an increased risk of cardiovascular disease,osteoporosis, muscle wasting and diabetes mellitus. Cardiovascular disease is a major cause of death in such patients and it may be related to excess stiffening of the walls of major arteries, such as the aorta, and it has been suggested to represent premature aging. However, there is little known of the development of these problems, which were previously considered to be due to smoking and which is now known not to be the only factor. The investigators will study a large group of patients with mild to very severe airflow obstruction based on the NICE 2010 classification of severity and a matched comparator group free of COPD. This study involves three assessments of the development of the complications of COPD over a five year period. The key measure will be the rate of change in the aortic wall stiffness, an accepted indicator of the risk of heart disease. Changes in wall stiffness will be related to the severity of lung disease; other known cardiovascular risk factors, such as high blood pressure, increased blood cholesterol and to cardiovascular events including heart attacks and death; and to the presence of other complications, such as osteoporosis, muscle wasting and diabetes mellitus. These measures will be analysed in the context of changes in bodywide inflammation and metabolic function and the changes in the rate of ageing. This increased knowledge of interacting factors in the complications of COPD is likely to lead to studies of treatments to avoid their development.