Uusi-Rasi K, Sievänen H, Pasanen M, Oja P, Vuori I
UKK Institute for Health Promotion Research, PO Box 30, FIN-33501 Tampere, Finland.
Osteoporos Int. 2001;12(5):373-9. doi: 10.1007/s001980170105.
This prospective study focused on lifestyle factors and weight maintenance that may modulate the rate of bone loss at the weight-bearing proximal femur and non-weight-bearing distal radius in elderly women. Altogether 128 women of 134 subjects participated in this study with a mean follow-up time 3.9 years (range 2.9-5.3 years). The initially 60- to 65-year-old subjects were originally selected by their level of physical activity [high (PA+) and low (PA-)] and calcium intake [high (Ca+) and low (Ca-)], and the original groups were maintained in this study. Physical fitness and bone mineral content (BMC) decreased significantly at a similar rate in all four study groups without any statistically significant between-group difference. The mean change in the muscle strength of leg extensors was -3.3% (95% CI -5% to -1.5%) at follow-up when including all individuals. The leg extension strength was still 9.2% (95% CI 2.7% to 16.1%) better in the PA+ groups compared with PA- groups at follow-up. The mean change in the forearm flexion strength was -14% (95% CI -16.5% to -11.3%) at follow-up with no difference in the strength level between PA+ and PA- groups. The mean change in the estimated oxygen uptake was -3.4% (95% CI -5.6% to -1.1%) at follow-up. The PA+ groups were still fitter, the between-group difference in the estimated oxygen uptake being 11.9% (95% CI 4.8% to 19.5%). The mean changes in BMC at follow-up were -2.1% (95% CI -3.0% to -1.2%) at the femoral neck, -1.9% (95% CI -3.2% to -0.5%) at the trochanter, and -12.4% (95% CI -15.4% to -9.4%) at the distal radius, indicating mean annual losses of 0.6% (95% CI 0.3% to 0.8%), 0.5% (95% CI 0.1% to 0.8%), and 3.2% (95% CI 2.4% to 4.0%), respectively. Decreased body weight was associated with higher bone loss in all measured bone sites. High calcium intake and better preservation of physical fitness were associated with a smaller decrease in femoral neck BMC.
