NEW YORK (Reuters Health) – Computed tomography (CT) of the chest can serve a dual purpose in patients with chronic obstructive pulmonary disease (COPD), measuring both the severity of emphysema and vertebral bone density, physicians in Japan report.

The multiple extrapulmonary features associated with COPD indicate that it is a systemic disease, Dr. Toyohiro Hirai and colleagues at Kyoto University note in the December issue of the journal Chest; one such feature is osteoporosis. However, the association between the degree of pulmonary involvement and loss of bone density is unclear.

Their cross-sectional survey included 65 clinically stable men with COPD and no history of bone disease or use of corticosteroids or other medicines that influence bone metabolism. The average patient age was 68.8 years old.

The average CT scan density of the thoracic vertebrae (T4, T7 and T10) was used to determine bone mineral density, and the percentage of low-attenuation area in the lungs was used as a quantitative measure of pulmonary emphysema.