Determinants of bone loss in elderly men and women: A prospective population-based study

While several studies have described the rate and pattern of involutional b one loss in women, far less information is available for men. Furthermore. the roles of lifestyle and body build in determining bone loss rate in both sexes have been largely extrapolated from cross-sectional studies. We addr essed this issue in a population-based longitudinal study which sought to a scertain rates of bone loss at the femoral neck and lumbar spine in a cohor t of men and women aged 60-75 years at baseline, and to relate this loss to anthropometric and lifestyle variables. We additionally investigated the c apacity of biochemical markers of bone turnover to predict bone loss rates in these subjects. Women lost bone at all sites; this ranged from 0.20%/yea r at the lumbar spine to 1.43%/year at the femoral trochanteric region. By contrast, men lost only 0.20%/year at the trochanteric region, and gained a t the lumbar spine (0.33%/year) and at Ward's triangle (0.27%/year) over th e F-year period. Anthropometric measurements were associated with bone loss in both sexes; lower baseline body mass index (BMI) and a greater rate of loss of adiposity over the follow-up period were both associated with great er bone loss at all proximal femoral sites. These attained statistical sign ificance after Bonferroni correction at the total proximal femur among both men (r = 0.29), p<0.01) and women (r = 0.31, p<0.05). Lifestyle factors as sociated with lower rates of bone loss (after adjustment for BMI) included alcohol consumption at the femoral neck among women (p = 0.007) and physica l activity at the lumbar spine among men (p=0.05). Serum parathyroid hormon e, 25-hydroxyvitamin D and biochemical markers of bone turnover did not pre dict bone loss after adjustment for adiposity.