Age, menopause, bone turnover markers and lumbar bone loss in healthy Japanese women

The change in lumbar vertebral bone mineral density (BMD) during a 2-year study period was examined in 167 healthy middle-aged and elderly Japanese women with reference to age, menopausal status and bone turnover markers at baseline. The perimenopausal and postmenopausal groups of the subjects showed a significant loss of BMD during the study period but the premenopausal women did not. The annual percent decrease of BMD (Delta BMD) in the perimenopausal women (- 2.40% in average) was significantly greater than that in either of the premenopausal (- 0.01%) or over-all postmenopausal women (- 0.85%). The subjects who had been postmenopausal for less than 10 years showed a significant bone loss. Delta BMD in the postmenopausal women became less marked as the postmenopausal duration increased. The bone loss was accelerated for about 10 years after menopause. The pattern and magnitude of bone loss of Japanese women seemed to be similar to those of Caucasian women. The regression equation for Delta BMD based on the bone turnover markers at baseline was shown to be significant in the postmenopausal women and the serum level of bone-specific alkaline phosphatase isoenzyme had a significant relation to Delta BMD. However, this equation accounted for only 17.3% of the total variance of Delta BMD and, hence, its validity was not sufficiently high for the prediction of bone loss in clinical settings.