Abstract
Low bone mineral density (BMD) increases fracture risk, poor life-quality, and death. Low BMD is prevalent in tobacco-exposed individuals with lung disease; however, they are not included in current screening guidelines. In our study, a majority of individuals with former tobacco exposure not meeting current screening criteria had low BMD. PURPOSE: Low bone mineral density (BMD) is prevalent in tobacco-exposed individuals with lung disease. Guidelines recommend dual x-ray absorptiometry (DXA) screening for osteoporosis in individuals with current tobacco use, but former tobacco use, chronic obstructive pulmonary disease (COPD), and emphysema are not recommended indications for screening. We hypothesized that tobacco-exposed individuals not meeting current osteoporosis screening guidelines have a high prevalence of low BMD, and that low BMD associates with lung-specific risk factors in this population. METHODS: We measured total hip, femoral neck, and lumbar spine BMD with DXA in a tobacco-exposed cohort of men and women 40 years of age and older with ≥ 10 pack years cigarette use. Osteoporosis screening eligibility was determined by modified Fracture Risk Assessment Tool (FRAX) criteria. We investigated lung-related factors associated with low BMD adjusting for age, sex, and diabetes. RESULTS: Of 472 individuals with former tobacco exposure, 28% did not meet study-defined osteoporosis screening criteria. Of participants not meeting screening criteria, 55% had low BMD on DXA assessment. The presence of CT-determined emphysema was associated with low BMD (adjusted OR 2.1, 95% CI [1.02, 4.42]) in participants not eligible for osteoporosis screening. Lung function, respiratory symptoms, pack years cigarette use, and inhaled corticosteroid use were not associated with low BMD. CONCLUSION: Emphysema on chest CT scan independently associates with low BMD in tobacco-exposed individuals not meeting traditional osteoporosis screening criteria. These findings suggest that osteoporosis screening recommendations should include emphysema as a risk factor for early BMD assessment.