Effects of walking on the preservation of bone mineral density in perimenopausal and postmenopausal women: a systematic review and meta-analysis.

OBJECTIVE This study aims to critically evaluate the effects of a walking intervention on bone mineral density (BMD) in perimenopausal and postmenopausal women and to identify the optimal duration of this walking exercise intervention. METHODS Two independent reviewers assessed for eligibility randomized and nonrandomized controlled trials evaluating the effects of walking on BMD in perimenopausal and postmenopausal women. Heterogeneity, potential publication bias, and the quality of the included trials were assessed. RESULTS Ten trials were eligible for inclusion. A meta-analysis of trials assessing lumbar spine BMD showed no significant effects (weighted mean difference [WMD] [fixed effects], 0.01 g/cm(2); 95% CI, -0.00 to 0.02; P = 0.05) regardless of the length of the intervention duration. BMD at the femoral neck increased after long intervention durations (6 mo to 1-2 y), although no significant effect could be seen when all trials assessing femoral neck BMD were taken into account (WMD [fixed effects], 0.01 g/cm(2); 95% CI, -0.00 to 0.01; P = 0.07). The effects of walking on the radius and whole body were not significant (WMD [random effects], -0.01 g/cm; 95% CI, -0.06 to 0.04; P = 0.71; and WMD [fixed effects], 0.04 g/cm(2); 95% CI, -0.00 to 0.08; P = 0.06, respectively). CONCLUSIONS Walking as a singular exercise therapy has no significant effects on BMD at the lumbar spine, at the radius, or for the whole body in perimenopausal and postmenopausal women, although significant and positive effects on femoral neck BMD in this population are evident with interventions more than 6 months in duration.