Body composition and osteoporosis in elderly women

To study body composition in elderly osteoporotic women to determine the relationship of body weight, body fat mass and lean mass to bone mineral density (BMD), and to investigate the association between one-leg balance, osteoporosis and sarcopenia.

A cross-sectional study of a community-based population in Toulouse, France.

For each participant, whole body composition and BMD were estimated using a dual-energy x-ray absorptiometry scanner. We investigated balance using a one-leg balance test.

129 healthy women aged 75-89 years, volunteers, ambulatory and living at home.

Total fat mass and appendicular skeletal muscle mass (ASM) were significantly lower in osteoporotic women than in the age- and sex-matched non-osteoporotic controls [18.7 +/- 4.6 vs. 22.2 +/- 6.6 for total fat mass (p < 0.01); 13.1 +/- 1.6 vs. 13.8 +/- 2.2 for ASM (p < 0. 05)]. We did not find a positive association between osteoporosis and sarcopenia (OR = 0.75, CI 0.3-1.84), osteoporosis and one-leg balance (OR = 1.27, CI 0.51-3.17), or sarcopenia and one-leg balance (OR = 1.31, CI 0.52-3.36). There were significant positive correlations between BMD in all areas and body measurements (weight, fat mass, lean tissue mass), but fat mass accounted for more of the variance in total body and femoral BMD than lean tissue mass. Total fat mass alone, in a multivariate model, was correlated with whole body BMD, whereas femoral BMD was associated with both fat mass and lean tissue mass.

Higher values of fat mass and lean tissue mass may have a protective effect on femoral bone density. Sarcopenia and osteoporosis are not necessarily linked with balance.