Bone changes in postmenopausal Spanish women.

Total body bone mass (TBBM), axial bone mass (trunk = chest and spine), and peripheral bone mass (arms and legs) were determined in 258 normal, slow bone mass loser, postmenopausal women, as determined by previous biochemical studies, in order to study the degree of bone mass reduction due to menopause. The subjects of this study were divided into 5-year groups on a year-since-menopause basis. The first group corresponded to 1-5 years since menopause, and the last group to 25 years or over since menopause. An important and significant reduction in trunk bone mass (-12.3%, P < 0.001) and TBBD (-5.8%, P < 0.002), without changes in head, arms, and legs was observed in the first 5-year group. In the next 5-year group, a significant reduction was observed in all body areas, but at a higher rate in the peripheral skeleton (-9% in arms and -7.3% in legs). A slow down in bone mass loss was observed in the period between 10 and 25 years since menopause. These values became significant again after 25 years since menopause at the axial (-28.9%, P < 0.001) and TBBD (-20.3%, P < 0.05) level. Aside from providing percentages of bone mass reduction with respect to age and time since menopause, these data also indicate that measurements of specific body areas may not be extrapolated to others due to different loss in different body areas, and that there is a marked bone loss rate in the axial skeleton in the first 5 years since menopause.