Utility of Dxa Screening for Diagnosis of Osteoporosis in Us Veterans Aged 70 Years and Older

Abstract

Dual energy X-ray absorptiometry (DXA) is recommended for osteoporosis screening in men aged 70 years and older but supportive data is limited. The aim of this study was to determine the efficacy of DXA for the diagnosis of increased fragility in this group of subjects. We retrospectively identified men aged 70 years and older without prior history of fracture and/or conditions predisposing to low bone mineral density (BMD) who attended the VA endocrinology clinic and performed DXA for osteoporosis screening. We analyzed the relationship between BMD and demographic, anthropometric data and biochemical parameters using linear regression models. Out of 55 subjects identified, 13 (24%) men had normal BMD, 30 (54%) had osteopenia and 12 (22%) had a diagnosis of osteoporosis based on the femoral neck (FN) T-score. Lumbar spine T-scores were normal in all three groups. Weight and body mass index (BMI) were significantly higher in the normal BMD group compared with the osteopenia and osteoporosis groups (p<0.001). After adjustments for age, weight, BMI, vitamin D concentrations, and diabetes status, differences in the FN BMD among the groups remained significant (p<0.001). Based on the Fracture Risk Assessment Tool (FRAX) score calculations in 43 non-osteoporotic patients, 15 patients with osteopenia had a 10-year hip fracture probability ≥3%. Screening with DXA in male US veterans aged 70 years and older without known osteoporosis risk factors revealed that up to 50% of men may qualify for diagnostic workup to determine the etiology of low BMD and/or to meet criteria to initiate pharmacological therapy to reduce future fracture risk.