COMPARISON OF AREAL AND ESTIMATED VOLUMETRIC BONE-MINERAL DENSITY VALUES BETWEEN OLDER MEN AND WOMEN

We compared areal bone mineral density (BMD) of the total body (TBMD), antero-posterior lumbar spine at L3 (APS), lateral spine at L3 (LS) a nd femoral neck (FN). In order to understand better the effect of-gend er-related size differences on BMD, we also compared the estimated vol umetric BMD at L3 (VLS) and the femoral neck (VFN). Subjects were asym ptomatic women (n = 22) and men (n = 44) with an age range of 58-79 ye ars. BMD at each site was measured by dual-energy X-ray absorptiometry using a Hologic 2000 in array mode. Results of the statistical analys es (ANOVA) showed the men to have significantly greater BMD at all are al sites [APS, LS (p <0.05); FN (p <0.01); TBMD (p <0.001)]. The two e stimated volumetric comparisons, however, showed no gender differences . Results demonstrate how measures from areal BMD measures can be misl eading when comparing groups of different size. In older men and women planar measures may overestimate gender differences in BMD.