Bone mineral density in emphysema and chronic bronchitis phenotypes in hospitalized male chronic obstructive pulmonary disease patients

Introduction: Risk of osteoporosis known to increase in chronic obstructive pulmonary disease (COPD), but is usually overlooked, especially in male patients. Objectives: The present study compares the bone mineral density (BMD) measurements of male COPD patients with emphysema and the chronic bronchitis phenotype, and evaluates the association between density of emphysema and osteoporosis. Methods: Ninety-four patients with COPD, and with emphysema and the chronic bronchitis phenotype, were included in the prospective study. A high-resolution computed tomography (HRCT) was used for the diagnosis of emphysema, and a dual X-ray absorptiometry was used to measure the BMD of the lumbar vertebrae and neck of the femur. Results: Emphysema phenotype 45.75% and chronic bronchitis phenotype 54.25%, based on their clinical findings and a quantitative volumetric analysis by HRCT. Osteoporosis was found 60.47% and 17.65% of patients with emphysema and bronchitis, while osteopenia was detected 27.91% and 41.18% of patients with emphysema and bronchitis, respectively. A negative correlation was found between HRCT emphysema density and the bone densitometer t-score in patients with osteoporosis. Among the patients with osteoporosis, a positive correlation was found between Body Mass Index (BMI) and the bone densitometer t-score. Only BMI and emphysema score were found to be independent risk factors for a low BMD. One unit drop in BMI increased the risk of osteoporosis by 28% (OR = 1.28, 95% CI 1.14-1.45) (P < 0.001). One unit increase in emphysema score increased the risk of osteoporosis by 6% (OR = 1.06, 95% CI 1.03-1.09) (P < 0.001). Conclusion: Especially male patients with emphysema, high dyspnea score, low BMI and frequent exacerbations should be evaluated for osteoporosis.