Beyer F R, Dickinson H O, Nicolson D J, Ford G A, Mason J
University of Newcastle, Centre for Health Services Research, 21 Claremont Place, Newcastle upon Tyne,Tyne & Wear, UK NE2 4AA.
Cochrane Database Syst Rev. 2006 Jul 19(3):CD004805. doi: 10.1002/14651858.CD004805.pub2.
Previous research suggests that increasing dietary intakes of calcium, potassium or magnesium separately may reduce BP to a small degree over the short term. It is unclear whether increasing intakes of a combination of these minerals produces a larger reduction in BP.
To evaluate the effects of combined mineral supplementation as a treatment for primary hypertension in adults.
We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials, CAB abstracts, and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review. The search was unrestricted by language or publication status.
Inclusion criteria were: 1) RCTs of a parallel or crossover design comparing oral supplements comprising a combination of potassium, and/or calcium, and/or magnesium with placebo, no treatment, or usual care; 2) treatment and follow-up >=8 weeks; 3) participants over 18 years old, with raised systolic blood pressure (SBP) >=140 mmHg or diastolic blood pressure (DBP) >=85 mmHg with no known primary cause; 4) SBP and DBP reported at end of follow-up. We excluded trials where participants were pregnant, or received antihypertensive medication which changed during the study.
Two reviewers independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted.
We included three RCTs (n=277) with between 24 and 28 weeks follow-up. Three combinations of minerals were investigated: potassium & magnesium, calcium & magnesium, and calcium & potassium. One trial investigated combinations of calcium & magnesium and of calcium & potassium, and for each found a statistically non-significant increase in both SBP and DBP. All three trials investigated the combination of potassium & magnesium. None of the trials provided data on mortality or morbidity. The combination of potassium & magnesium compared to control resulted in statistically non-significant reductions in both SBP (mean difference = -4.6 mmHg, 95% CI: -9.9 to 0.7) and DBP (mean difference = -3.8 mmHg, 95% CI: -9.5 to 1.8), although the results were heterogeneous (I(2)=68% and 85% for SBP and DBP respectively).A sensitivity analysis using alternative reported values which accounted for missing data had very little effect on DBP but resulted in a larger, statistically significant reduction in SBP (mean difference = -5.8 mmHg, 95% CI: -10.5 to -1.0). The quality of the trials was not well reported.
AUTHORS' CONCLUSIONS: We found no robust evidence that supplements of any combination of potassium, magnesium or calcium reduce mortality, morbidity or BP in adults. More trials are needed to investigate whether the combination of potassium & magnesium is effective.
先前的研究表明，短期内单独增加钙、钾或镁的膳食摄入量可能会使血压有小幅度降低。尚不清楚增加这些矿物质组合的摄入量是否会使血压有更大幅度的降低。
评估联合补充矿物质作为成人原发性高血压治疗方法的效果。
我们检索了Cochrane图书馆、MEDLINE、EMBASE、科学引文索引、ISI会议录、ClinicalTrials.gov、当前对照试验、CAB文摘以及该综述中纳入的系统评价、荟萃分析和随机对照试验（RCT）的参考文献列表。检索不受语言或出版状态限制。
纳入标准为：1）平行或交叉设计的RCT，比较含钾和/或钙和/或镁的口服补充剂与安慰剂、无治疗或常规护理；2）治疗和随访时间≥8周；3）18岁以上参与者，收缩压（SBP）≥140 mmHg或舒张压（DBP）≥85 mmHg且无已知原发性病因；4）随访结束时报告SBP和DBP。我们排除了参与者怀孕或在研究期间接受了改变的抗高血压药物治疗的试验。
两名综述作者独立提取数据并评估试验质量。分歧通过讨论或第三位综述作者解决。进行了随机效应荟萃分析和敏感性分析。
我们纳入了3项RCT（n = 277），随访时间为24至28周。研究了三种矿物质组合：钾和镁、钙和镁、钙和钾。一项试验研究了钙和镁以及钙和钾的组合，每项均发现SBP和DBP在统计学上无显著升高。所有三项试验都研究了钾和镁的组合。没有一项试验提供关于死亡率或发病率的数据。与对照组相比，钾和镁的组合使SBP（平均差值=-4.6 mmHg，95%CI：-9.9至0.7）和DBP（平均差值=-3.8 mmHg，95%CI：-9.5至1.8）在统计学上均无显著降低，尽管结果具有异质性（SBP和DBP的I²分别为68%和85%）。使用考虑了缺失数据的替代报告值进行的敏感性分析对DBP影响很小，但导致SBP有更大幅度的、具有统计学意义的降低（平均差值=-5.8 mmHg，95%CI：-10.5至-1.0）。试验质量报告不佳。
我们没有找到有力证据表明补充钾、镁或钙的任何组合可降低成人的死亡率、发病率或血压。需要更多试验来研究钾和镁的组合是否有效。
