A comparison of bone mineral density in elderly female patients with COPD and bronchial asthma

Background: A recent study has shown that osteoporosis and vertebral fractures are quitecommon in patients with advanced COPD and showed a significant relationship to the mortality of these patients. These results suggested that management of osteoporosis in advanced COPD is an important intervention. But whether patients with COPD who had never received chronic systemic corticosteroids have a high incidence of osteoporosis and whether these patients require treatment strategies to decrease osteoporotic fracture is not yet known. Furthermore, it is unclear whether there are differences in terms of the degree of osteoporosis between patients with COPD and patients with bronchial asthma. Objectives: To compare the degree of osteoporosis and bone metabolism markers between elderly women with COPD and those with bronchial asthma who had never received chronic systemic corticosteroids, and to determine the factors influencing bone metabolism in these patients. Design: Cross-sectional medical survey. Patients: A total of 44 elderly female patients with COPD (n=20) or bronchial asthma (n=24) who had not received chronic systemic corticosteroids were enrolled (mean+/-SEM age, 74.6+/-1.0 years). Measurements: Total body and lumbar bone mineral density (BMD) were measured by dual-energy x-ray absorptiometry, and the data were compared between the two groups. In addition, the association between bone mass and clinical variables was determined. Results: When lumbar BMD was expressed as a Z score, the Z scores of patients with COPD were significantly lower than those of patients with bronchial asthma (p<0.01). The prevalence of osteoporosis was also significantly higher in patients with COPD (50% vs 21%, p<0.05). In patients with COPD, body mass index was positively correlated with BMD in the lumbar spine (r=0.55, p=0.02) and total body (r=0.49, p=0.03). Other clinical, biochemical, and anthropometric variables were not correlated with BMD. Conclusions: In elderly female patients, osteoporosis is more common in cases of COPD than in bronchial asthma, even if these patients had not received long-term systemic corticosteroids. The explanation for the higher prevalence of osteoporosis in COPD is still not known, but preventive strategies to decrease osteoporotic fractures should be added to the management of elderly patients with COPD.