| Summary: | This study was undertaken to determine the degree of interaction between hormonal and athletic effects on changes in bone mineral density (BMD, g/cm(2)) with time in women around the menopause. Thirty-five elite female runners aged over 40 participated in a longitudinal cohort study of hip and spine bone density changes and had two measurements a mean of 4.1 years apart. Eighteen remained estrogenized throughout the study (E+ to +), ten remained postmenopausal throughout (E- to -), while seven showed a change in status (E- to +) or (E+ to -). At study exit, both postmenopausal E+ and E- subjects had significantly higher than expected broadband ultrasound attenuation (BUA) and velocity of sound (VOS) values at the calcaneus. However, Z-score 95% confidence intervals for BMD of the hip and spine embraced zero except at the femoral trochanter in E+ women. The E+ to + group did not lose bone at any site. The E- to - group lost bone significantly, but only at the femoral neck and spine at rates close to 1% annually. Multiple analysis of variance repeated measures analysis showed a significant interaction in the effects of estrogen exposure with DXA measurement site, with the femoral trochanter being less affected by E- status than the spine and femoral neck. Body mass index (BMI: weight/height(2), kg/m(2)) had a significantly positive effect on total hip and femoral neck BMD independently of estrogen status. In conclusion, in this pilot study, postmenopausal elite runners not on hormone replacement therapy lost BMD from the femoral neck and spine at the expected rates but in the femoral trochanter bone loss appeared reduced and in the calcaneus BUA and VOS were maintained close to young normal values.
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