[Influence of body weight variations on the rate of bone loss at the beginning of menopause].

Numerous data suggest, at any age, a clear relationship between body weight and Bone Mineral Density (BMD). On the other hand, the effects of individual changes in body weight on BMD are still poorly understood. Fourty four normal women of normal weight, who had passed a natural menopause 6 months to 5 years earlier, were followed during a mean period of time of 40 months. They all underwent three BMD measurements by Dual X-Ray Absorptiometry and a clinical examination. There was a significant correlation (p < 0.05) between the changes in weight and the changes in BMD at the vertebral (r = 0.31) and femoral (r = 0.30) levels. This association remained significant after adjustment for physical characteristics, age, years since menopause and initial BMD values. Moreover, the subgroup of women who gained more than one kilogram during the follow-up had a rate of bone loss which was about twice less than that in the rest of the group. This longitudinal study shows that changes in body weight are able to influence the rate of postmenopausal bone loss through mechanisms that are still discussed.