BMJ：老年妇女补钙可能增加心脏病风险
生物谷报道：医生常常会给绝经后的妇女开出补钙的处方，以保持骨骼的健康。此外还有数据表明，钙能够降低血液中的胆固醇，从而防止血管疾病的发生。
但这些理论缺乏证据，因此奥克兰大学（University of Auckland）的科学家决定研究补钙对心脏病（心肌梗塞）的影响、中风和暴毙的影响。
他们分析了1,472个55岁以上的妇女，她们也参加了之前关于钙对骨密度和骨折率的研究。
这些妇女每天随机给服钙补充剂或安慰剂。食物中的钙也进行测定，并且5年间每半年对这些妇女作一次检查。每次检查均记录下不良事件。服用钙的一组更容易出现心脏病。三个血管疾病（心脏病、中风和暴毙）在服用钙的一组发生率也较高。
因为这些研究结果的意义十分重大，所以研究人员到医院住院部检查了她们的死亡证书，以确定没有遗漏任何死亡的报告。
在服用钙的一组，31个妇女中出现36次心脏病发作，而服用安慰剂的一组，21个妇女中仅出现22次。心脏病、中风和暴毙的几率，在钙的一组也较高，尽管差异并不十分显著：60个妇女中出现76次，而安慰剂一组50个妇女中出现54次。
作者说，这些发现并不是结论性的，但表明摄入大量的钙可能会对血管的健康造成损害，需要特别注意。如果这个结果能被其它研究所证实的话，那就意味着补钙是得不偿失的。
该研究发表在1月16日的British Medical Journal （在线版）上。
生物谷推荐原始出处：
BMJ, doi:10.1136/bmj.39440.525752.BE (published 15 January 2008)
Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial
Mark J Bolland, research fellow1, P Alan Barber, senior lecturer1, Robert N Doughty, associate professor1, Barbara Mason, research officer1, Anne Horne, research fellow1, Ruth Ames, research officer1, Gregory D Gamble, research fellow1, Andrew Grey, associate professor1, Ian R Reid, professor1
1 Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
Correspondence to: I R Reid i.reid@auckland.ac.nz
Abstract
Objective To determine the effect of calcium supplementation on myocardial infarction, stroke, and sudden death in healthy postmenopausal women.
Design Randomised, placebo controlled trial.
Setting Academic medical centre in an urban setting in New Zealand.
Participants 1471 postmenopausal women (mean age 74): 732 were randomised to calcium supplementation and 739 to placebo.
Main outcome measures Adverse cardiovascular events over five years: death, sudden death, myocardial infarction, angina, other chest pain, stroke, transient ischaemic attack, and a composite end point of myocardial infarction, stroke, or sudden death.
Results Myocardial infarction was more commonly reported in the calcium group than in the placebo group (45 events in 31 women v 19 events in 14 women, P=0.01). The composite end point of myocardial infarction, stroke, or sudden death was also more common in the calcium group (101 events in 69 women v 54 events in 42 women, P=0.008). After adjudication myocardial infarction remained more common in the calcium group (24 events in 21 women v 10 events in 10 women, relative risk 2.12, 95% confidence interval 1.01 to 4.47). For the composite end point 61 events were verified in 51 women in the calcium group and 36 events in 35 women in the placebo group (relative risk 1.47, 0.97 to 2.23). When unreported events were added from the national database of hospital admissions in New Zealand the relative risk of myocardial infarction was 1.49 (0.86 to 2.57) and that of the composite end point was 1.21 (0.84 to 1.74). The respective rate ratios were 1.67 (95% confidence intervals 0.98 to 2.87) and 1.43 (1.01 to 2.04); event rates: placebo 16.3/1000 person years, calcium 23.3/1000 person years. For stroke (including unreported events) the relative risk was 1.37 (0.83 to 2.28) and the rate ratio was 1.45 (0.88 to 2.49).
Conclusion Calcium supplementation in healthy postmenopausal women is associated with upward trends in cardiovascular event rates. This potentially detrimental effect should be balanced against the likely benefits of calcium on bone.
Trial registration Australian Clinical Trials Registry ACTRN 012605000242628.
全文链接：http://www.bmj.com/cgi/content/full/bmj.39440.525752.BEv1?q=rss_home
- 众说风云 (已有0条评论)
