Meta-Analytic Research Group, School of Public Health, Department of Biostatistics, Robert C, Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506-9190, USA.
BMC Musculoskelet Disord. 2012 Sep 20;13:177. doi: 10.1186/1471-2474-13-177.
Low bone mineral density (BMD) and subsequent fractures are a major public health problem in postmenopausal women. The purpose of this study was to use the aggregate data meta-analytic approach to examine the effects of ground (for example, walking) and/or joint reaction (for example, strength training) exercise on femoral neck (FN) and lumbar spine (LS) BMD in postmenopausal women.
The a priori inclusion criteria were: (1) randomized controlled trials, (2) exercise intervention ≥ 24 weeks, (3) comparative control group, (4) postmenopausal women, (5) participants not regularly active, i.e., less than 150 minutes of moderate intensity (3.0 to 5.9 metabolic equivalents) weight bearing endurance activity per week, less than 75 minutes of vigorous intensity (> 6.0 metabolic equivalents) weight bearing endurance activity per week, resistance training < 2 times per week, (6) published and unpublished studies in any language since January 1, 1989, (7) BMD data available at the FN and/or LS. Studies were located by searching six electronic databases, cross-referencing, hand searching and expert review. Dual selection of studies and data abstraction were performed. Hedge's standardized effect size (g) was calculated for each FN and LS BMD result and pooled using random-effects models. Z-score alpha values, 95%confidence intervals (CI) and number-needed-to-treat (NNT) were calculated for pooled results. Heterogeneity was examined using Q and I2. Mixed-effects ANOVA and simple meta-regression were used to examine changes in FN and LS BMD according to selected categorical and continuous variables. Statistical significance was set at an alpha value ≤0.05 and a trend at >0.05 to ≤ 0.10.
Small, statistically significant exercise minus control group improvements were found for both FN (28 g's, 1632 participants, g = 0.288, 95% CI = 0.102, 0.474, p = 0.002, Q = 90.5, p < 0.0001, I2 = 70.1%, NNT = 6) and LS (28 g's, 1504 participants, g = 0.179, 95% CI = -0.003, 0.361, p = 0.05, Q = 77.7, p < 0.0001, I2 = 65.3%, NNT = 6) BMD. Clinically, it was estimated that the overall changes in FN and LS would reduce the 20-year relative risk of osteoporotic fracture at any site by approximately 11% and 10%, respectively. None of the mixed-effects ANOVA analyses were statistically significant. Statistically significant, or a trend for statistically significant, associations were observed for changes in FN and LS BMD and 20 different predictors.
The overall findings suggest that exercise may result in clinically relevant benefits to FN and LS BMD in postmenopausal women. Several of the observed associations appear worthy of further investigation in well-designed randomized controlled trials.
骨密度（BMD）降低和随后的骨折是绝经后妇女面临的一个主要公共卫生问题。本研究旨在采用汇总数据分析方法，研究地面（例如，步行）和/或关节反应（例如，力量训练）对绝经后妇女股骨颈（FN）和腰椎（LS）BMD 的影响。
预先确定的纳入标准为：（1）随机对照试验，（2）运动干预≥24 周，（3）对照比较组，（4）绝经后妇女，（5）非定期活动者，即每周中度强度（3.0 至 5.9 代谢当量）承重耐力活动少于 150 分钟，每周剧烈强度（>6.0 代谢当量）承重耐力活动少于 75 分钟，每周阻力训练次数少于 2 次，（6）自 1989 年 1 月 1 日起以任何语言发表和未发表的研究，（7）FN 和/或 LS 处可获得 BMD 数据。通过搜索六个电子数据库、交叉引用、手工搜索和专家审查来定位研究。对研究和数据提取进行双重选择。为每个 FN 和 LS BMD 结果计算 Hedge 的标准化效应大小（g），并使用随机效应模型进行汇总。为汇总结果计算 Z 分数阿尔法值、95%置信区间（CI）和需要治疗的人数（NNT）。使用 Q 和 I2 检查异质性。使用混合效应 ANOVA 和简单的荟萃回归来检查 FN 和 LS BMD 根据选定的分类和连续变量的变化。统计学显著性设定为 alpha 值≤0.05，趋势为>0.05 至≤0.10。
发现 FN（28 g，1632 名参与者，g=0.288，95%CI=0.102，0.474，p=0.002，Q=90.5，p<0.0001，I2=70.1%，NNT=6）和 LS（28 g，1504 名参与者，g=0.179，95%CI=-0.003，0.361，p=0.05，Q=77.7，p<0.0001，I2=65.3%，NNT=6）BMD 的运动与对照组之间存在统计学意义上的较小但有意义的改善。临床上，估计 FN 和 LS 的整体变化将使绝经后妇女任何部位骨质疏松性骨折的 20 年相对风险降低约 11%和 10%。没有一项混合效应方差分析具有统计学意义。FN 和 LS BMD 与 20 个不同预测因子的变化之间观察到统计学意义上的显著或趋势显著关联。
总体研究结果表明，运动可能会使绝经后妇女的 FN 和 LS BMD 产生临床相关的获益。观察到的一些关联似乎值得在精心设计的随机对照试验中进一步研究。
