Prevalence, risk factors, and health-related quality of life of osteoporosis in patients with COPD at a community hospital in Taiwan

BACKGROUND Data regarding osteoporosis in COPD patients in Taiwan remain limited. The primary end point of this study was to evaluate the prevalence and risk factors of osteoporosis in COPD patients in Taiwan. The secondary end point was to examine the association between osteoporosis and health-related quality of life (HRQL) in COPD patients. MATERIALS AND METHODS This prospective cross-sectional study enrolled 125 COPD patients (mean age 73.6 years, forced expiratory volume in 1 second [FEV1] 1.19±0.43 L) who had bone mineral-density measurements performed consecutively. Demographic data, lung function, and HRQL including modified Medical Research Council dyspnea scale, St George's Respiratory Questionnaire, oxygen-cost diagram, Center for Epidemiologic Studies - depression scale, and COPD Assessment Test scores were recorded. RESULTS A total of 50 (40%) participants were diagnosed as having osteoporosis. In a multivariate logistic regression model including age, smoking amount (pack-year), body mass index (BMI), and FEV1, only BMI (odds ratio 0.824, 95% confidence interval 0.73-0.93; P=0.002) and FEV1 (odds ratio 0.360, 95% confidence interval 0.13-0.98; P=0.046) were negatively associated with an increased risk of osteoporosis in COPD patients. In addition, COPD patients with osteoporosis had significantly higher modified Medical Research Council dyspnea scale scores (1.7±0.8 vs 1.4±0.8, P=0.046), St George's Respiratory Questionnaire scores (36.6 vs 28.0, P=0.01), and COPD Assessment Test scores (14.7±8 vs 11.5±7, P=0.019), and lower oxygen-cost diagram score (4.8±1.8 vs 5.4±1.6, P=0.045) than patients without osteoporosis. CONCLUSION The prevalence of osteoporosis in COPD patients was high at a community hospital in Taiwan. BMI and FEV1 were the independent risk factors for osteoporosis in COPD. In addition, COPD patients with osteoporosis had worse HRQL than those without osteoporosis.