The influence of dietary and nondietary calcium supplementation on blood pressure - An updated metaanalysis of randomized controlled trials
The influence of dietary and nondietary calcium supplementation on blood pressure - An updated metaanalysis of randomized controlled trials
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DOI：
10.1016/s0895-7061(98)00224-6
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发表时间：
1999-01-01
影响因子：
3.2
通讯作者：
Cook, DJ
中科院分区：
文献类型：
--
作者：
Griffith, LE;Guyatt, GH;Cook, DJ
我们更新了之前关于补充钙对血压影响的系统综述。我们将以前在MEDLINE和EMBASE上的检索扩展到1997年5月，并检查了相关文章的引文。我们联系了合格试验的作者，以确保数据的准确性和完整性，并确定未发表的试验。我们纳入了任何研究，其中研究人员将高血压或血压正常的人随机分配到钙补充剂或替代疗法，并测量血压至少2周。除了先前荟萃分析中纳入的32项试验外，还有10项新试验参与了本次荟萃分析。两对独立的审查者提取数据，并根据六个质量标准评估研究数据的有效性。我们计算了钙补充组和对照组之间血压变化的差异，并使用随机效应模型将每次试验的估计值合并，用方差的倒数加权。我们检查的血压降低的预测因素包括补充方法、基线血压和研究的方法学质量。汇总分析显示收缩压降低-1.44 mmHg（95%置信区间-2.20至-0.68; P < .001）和舒张压为-0.84 mm Hg（95%置信区间-1.44至-0.24; P < .001）。我们发现，各试验的结果具有统计学显著性异质性（P小于或等于0.02），当我们仅观察非饮食试验时，这种异质性仍然存在，但当我们将分析限制在饮食试验时，这种异质性就不存在了。虽然有一个趋势，对更大的影响与饮食干预，没有可能的介质的血压降低解释治疗effects.We的结论是，钙补充剂导致收缩压和舒张压的一个小的减少差异。在饮食中补充钙的效果至少与非饮食补充一样大。(C)1999年美国高血压杂志有限公司
We updated our previous systematic review of the effect of supplemental calcium on blood pressure. We extended our previous searches on MEDLINE and EMBASE to May 1997 and examined citations from relevant articles. We contacted the authors of eligible trials to ensure the accuracy and completeness of data, and to identify unpublished trials. We included any study in which investigators randomized hypertensive or normotensive people to calcium supplementation or alternative therapy and measured blood pressure for at least 2 weeks. In addition to 32 trials included in the prior metaanalysis, 10 new trials contributed to this metaanalysis. Two pairs of independent reviewers abstracted data and assessed the validity of the study data according to six quality criteria. We calculated the differences in blood pressure change between the calcium supplementation and control groups and pooled the estimates with each trial weighted with the inverse of the variance using a random effects model. The predictors of blood pressure reduction that we examined included method of supplementation, baseline blood pressure, and the methodologic quality of the studies.The pooled analysis shows a reduction in systolic blood pressure of -1.44 mm Hg (95% confidence interval -2.20 to -0.68; P < .001) and in diastolic blood pressure of -0.84 mm Hg (95% confidence interval -1.44 to -0.24; P < .001). We found statistically significant heterogeneity of results across trials (P less than or equal to .02), which persisted when we looked at the nondietary trials alone, but not when we restricted our analysis to dietary trials. Although there was a trend toward larger effects with dietary interventions, none of the possible mediators of blood pressure reduction explained differences in treatment effect.We conclude that calcium supplementation leads to a small reduction in systolic and diastolic blood pressure. The effect of supplemental calcium in the diet is at least as great as nondietary supplementation. (C) 1999 American Journal of Hypertension, Ltd.