Despite low quality of reporting, exercise has small but statistically significant effect in meta-analysis
TUESDAY, July 19 (HealthDay News) -- Exercise is suggested to have a small but statistically significant effect on preventing bone mineral density (BMD) loss in postmenopausal women, according to a meta-analysis published in the July issue of the Cochrane Database of Systematic Reviews.
Tracey E. Howe, Ph.D., from Glasgow Caledonian University in the United Kingdom, and colleagues reviewed available literature through December 2010 to examine the effectiveness of exercise interventions in preventing bone loss and fractures in postmenopausal women. A total of 43 randomized controlled trials, with 4,320 participants, were included in the analysis. Using a fixed-effect model, risk ratios were calculated for dichotomous outcomes (fractures), whereas mean differences (MDs) of percentage change from baseline were evaluated for continuous data. A random-effect model was used in cases where heterogeneity existed.
The investigators found that non-weight-bearing high-force exercise, such as progressive resistance strength training for the lower limb, appeared to be the most effective exercise intervention on BMD for neck of femur (MD, 1.03; 95 percent confidence interval [CI], 0.24 to 1.82). Compared to controls, combination exercise programs were most effective for BMD at the spine (MD, 3.22). No effect was observed on number of fractures (odds ratio, 0.61; 95 percent CI, 0.23 to 1.64). The studies included in the meta-analyses had low-quality reporting, especially in the areas of sequence generation, allocation concealment, blinding, and loss to follow-up.
"Results suggest a relatively small statistically significant, but possibly important, effect of exercise on bone density in postmenopausal women compared with control groups," the authors write.
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