Relationships among measurement of bone mineral density in thoracic spine, lumbar spine and hip in newly menopausal women

Analyses were performed to determine the status of bone mineral density (BMD) with different modalities with the goal of providing efficient, accurate screening with reduced testing burden. Volumetric BMD (vBMD) in thoracic spine was measured from images obtained to determine coronary arterial calcification using 64‐slice computed tomography in women being screened for the Kronos Early Estrogen Prevention Study (KEEPS), employing the Spine Cancer Assessment program. These women also underwent areal BMD (aBMD) using dual X‐ray absorptiometry (DXA) in lumbar spine and hip. Women (n=111) were 52.3±2.4 years of age and 18.5±9.5 months past their last menses. Mean trabecular vBMD from Th7 to Th9 was 166.6±29.4 mg/cc, mean of lumbar spine aBMD from L2 to L4 was 1.19±0.16 g/cm 2 . Mean total hip aBMD was 0.98±0.12 g/cm 2 . There was a positive correlation between vBMD in thoracic spine and aBMD of lumbar spine and hip: R=0.68, R=0.52, respectively. No subject had a DXA T‐score < −2.5 defining osteoporosis. T‐scores were calculated from the thoracic trabecular vBMD using the formula reported in the literature. Ten women had a vBMD T‐score < −2.5. These results suggest that thoracic vBMD can be obtained from scans used to evaluate coronary arterial calcification and may provide a sensitive screening of bone calcification. Additional work is needed to determine if this method allows for longitudinal evaluation of BMD. (Supported by the Kronos Longevity Research Institute and the Mayo Clinic)