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International Journal of Endocrinology
Volume 2013 (2013), Article ID 741639, 16 pages
http://dx.doi.org/10.1155/2013/741639
Review Article

Exercise and Bone Mineral Density in Premenopausal Women: A Meta-Analysis of Randomized Controlled Trials

1Department of Community Medicine, West Virginia University, Morgantown, WV 26506, USA
2Meta-Analytic Research Group, Department of Biostatistics, School of Public Health, Robert C. Byrd Health Sciences Center, West Virginia University, P.O. Box 9190, Morgantown, WV 26506-9190, USA
3Division of Geriatric Medicine, University of Colorado Denver, Anschutz Medical Campus, P.O. Box 6511, Mail Stop B179, 12631 East 17th Avenue-L15, Aurora, CO 80045, USA

Received 18 August 2012; Revised 27 October 2012; Accepted 6 November 2012

Academic Editor: Vin Tangpricha

Copyright © 2012 George A. Kelley et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective. Examine the effects of exercise on femoral neck (FN) and lumbar spine (LS) bone mineral density (BMD) in premenopausal women. Methods. Meta-analysis of randomized controlled exercise trials ≥24 weeks in premenopausal women. Standardized effect sizes ( ) were calculated for each result and pooled using random-effects models, score alpha values, 95% confidence intervals (CIs), and number needed to treat (NNT). Heterogeneity was examined using and . Moderator and predictor analyses using mixed-effects ANOVA and simple metaregression were conducted. Statistical significance was set at . Results. Statistically significant improvements were found for both FN (7 's, 466 participants, , 95%   , 0.553, , , , %, ) and LS (6 's, 402 participants, , 95%   , 0.394, , , , %, ) BMD. A trend for greater benefits in FN BMD was observed for studies published in countries other than the United States and for those who participated in home versus facility-based exercise. Statistically significant, or a trend for statistically significant, associations were observed for 7 different moderators and predictors, 6 for FN BMD and 1 for LS BMD. Conclusions. Exercise benefits FN and LS BMD in premenopausal women. The observed moderators and predictors deserve further investigation in well-designed randomized controlled trials.