Low bone mineral density and chronic obstructive pulmonary disease – A missed correlation

Abstract

Chronic obstructive pulmonary disease (COPD) is a disorder involving various other systems in the body apart from lungs. Such co-existence leads to worsening of disease control and associated increase in the morbidity as well as mortality of the diseased patients. They COPD patients are more prone for association with low fat free mass and low bone mineral density owing to pronounced persistent inflammation and various other associated risk factors. Low bone mineral density in those patients lead to the development of osteoporosis in those patients. Osteoporosis also worsens COPD and reduce their symptom free survival and reduction in day-to-day activities. However, the occurrence of osteoporosis in COPD patients is not well represented. The main objective is to study the occurrence of low bone mineral density leading to osteoporosis and osteopenia in COPD individuals and to propose various risk Factors leading to its development. This cross-sectional prevalence study was done in a tertiary care hospital in the department of Respiratory medicine over a period of 2 years. 100 diagnosed patients of COPD by spirometry (FEV/FVC < 0.70) according to GOLD guidelines were included in the study. Spirometry was done to group the patients in various grades of airflow obstruction severity and DXA scan of lumbar spine was done with the help of bone densitometer to determine the T-scores and to look for the presence of any reduction in Bone Mineral Density (BMI) satisfying WHO osteoporosis diagnostic guidelines. Among the 100 patients of COPD, 52 patients (52%) had osteoporosis and 22 patients (22%) had osteopenia. Majority of the patients (96.1%) who had osteoporosis were confined to stages 3 and 4 GOLD grading of severity of airflow obstruction. Patients in stages III and IV of airflow obstruction severity were found to have reduction in their bone mineral density. Underweight COPD patients were found to have higher cases of osteoporosis. On analysis; female sex, severe degree of airflow obstruction, Underweight, intake of higher doses of inhalational and oral or systemic corticosteroids, frequent exacerbations and deficiency of 1,25-Dihydrocholecalciferol were observed as risk factors for osteoporosis in COPD patients. In this study, the prevalence of osteoporosis and osteopenia were 52% and 22% respectively in the COPD patients. The risk of acquiring osteoporosis increased with the airflow obstruction severity. Thus, a high index of clinical suspicion and early diagnosis of it is essential to evaluate for osteoporosis in COPD and to treat it early to prevent further disability, morbidity and mortality and to improve the quality of life in COPD patients.