注册 登录  
 加关注
   显示下一条  |  关闭
温馨提示!由于新浪微博认证机制调整,您的新浪微博帐号绑定已过期,请重新绑定!立即重新绑定新浪微博》  |  关闭

gloryking3的博客

淡泊,宁静,无欲,无求,无为

 
 
 

日志

 
 

Calcium supplements raise CVD mortality only in men钙补充剂仅增加男性心血管疾病死亡率  

2013-02-24 09:54:02|  分类: 默认分类 |  标签: |举报 |字号 订阅

  下载LOFTER 我的照片书  |

根据2月4日《美国医学会杂志-内科学》在线发表的一项报告,服用钙补充剂增加心血管疾病(CVD)死亡风险似乎仅见于男性。另一方面,无论男女,从膳食中摄取钙对CVD死亡率均无明显影响[JAMA Intern. Med. 2013(doi:10.1001/jamainternmed.2013.3283)]。


美国国立癌症研究所的Qian Xiao博士及其同事报告称,虽然上述来自大规模前瞻性研究的结果尚不是最后定论,但进一步支持了“钙补充剂可能对心血管健康存在不利影响”这一存在争议的看法。然而,钙还广泛性参与人体许多生理过程,并且已知在某些方面有利于心血管健康,例如降低血压以及改善血脂等,因此有必要开展进一步的研究。考虑到人们广泛应用钙补充剂,评估钙补充剂对骨骼健康之外的其他作用非常重要。
 
研究者利用NIH-AARP饮食与健康研究数据,分析了受试者基线钙摄入量与心脏疾病、脑血管疾病以及其他CVD累计死亡率之间的关联性。共计随访219,059例男性和169,170例女性,年龄50~71岁。


男女受试者服用钙补充剂的比例分别为23%和56%,服用含钙多种维生素补充剂的比例分别为56%和58%。在12年随访期间,男女受试者CVD死亡例数分别为7,904例和3,874例。


Calcium supplements raise CVD mortality only in men钙补充剂仅增加男性心血管疾病死亡率 - gloryking3 - gloryking3的博客

分析结果显示,男性服用钙补充剂与总CVD死亡风险、心脏病死亡风险以及脑血管疾病死亡风险显著增加相关。此外,位于补钙量最高五分位的男性CVD死亡风险增加,主要归因于心脏疾病死亡风险提高。在女性受试者中,未见钙补充剂与上述所有结局之间存在关联。无论男性还是女性,膳食钙摄入与任何死亡结局均未见关联。


敏感性分析显示,排除随访最初2年所有死亡数据后,上述相关性不变。


根据受试者年龄、吸烟状况、体重指数、高血压、高胆固醇血症、镁摄入量以及饮酒情况进行分组后的分析显示,在大部分男性亚组中钙补充剂与死亡风险增加仍呈正相关。在女性受试者中,曾吸烟者、非高血压者以及高胆固醇血症者服用钙补充剂与CVD死亡率增加相关,其余亚组仍未见关联。


研究者认为,钙补充剂对心血管产生副作用的可能机制之一是磷酸钙在心血管结构中的沉积,即血管钙化。血凝增加和动脉硬化也与血清钙水平较高有关。


研究者还指出,性别差异令人关注,也值得深入研究。一种可能合理的推测是,通常男性开始服用钙补充剂时年龄相对较大,而女性更可能在该项研究开始之前早已达到钙平衡和稳态钙水平,使得钙补充剂的影响相对较小。


该研究由NHI、NCI和NIA资助,研究者无利益冲突披露。


随刊述评:膳食钙是钙补充剂的安全替代品


斯德哥尔摩卡罗林斯卡研究院的Susanna C. Larsson博士评论指出,该项大规模前瞻性观察研究为钙补充剂增加CVD死亡率提供了新的证据。“钙补充剂的安全替代品是富含钙的食物,诸如低脂乳制品、豆类和绿叶蔬菜。它们不仅富含钙,还含有多种必需的矿物质和维生素,可为食用者带来额外的健康益处,如改善糖尿病患者血糖控制(JAMA Intern. Med. 2013 [doi:10.1001/jamainternmed.2013.3769])。


Larsson博士报告无相关利益冲突。


原文


By: MARY ANN MOON


Taking calcium supplements appears to raise the risk of death from cardiovascular disease among men but not women, according to a report published online Feb. 4 in JAMA Internal Medicine.


In contrast, the intake of dietary calcium has no apparent effect on cardiovascular disease (CVD) mortality in either sex, said Qian Xiao, Ph.D., of the division of cancer epidemiology and genetics, National Cancer Institute, and her associates.


These findings from a large prospective study that followed 388,229 adults for 12 years are not definitive but provide further support for the controversial idea that supplemental calcium may have adverse effects on cardiovascular health. However, calcium also "is widely involved in many aspects of human physiology" and is known to benefit some aspects of cardiovascular health, such as lowering blood pressure and improving lipid profiles, so further study is warranted.


"Given the extensive use of calcium supplements in the population, it is of great importance to assess the effect of supplemental calcium use beyond bone health," Dr. Xiao and her colleagues wrote.


The investigators examined this issue using data from the National Institutes of Health–AARP Diet and Health Study, which assessed adults who were aged 50-71 years in 1995 and resided in California, Florida, Louisiana, New Jersey, North Carolina, Pennsylvania, Atlanta, and Detroit. For this study, the investigators followed 219,059 men and 169,170 women participants, correlating their calcium intake at baseline with cumulative mortality from heart disease, cerebrovascular disease, and other forms of CVD.


A total of 23% of the men and 56% of the women took calcium supplements, and 56% of the men and 58% of the women took multivitamins containing calcium. During follow-up there were 7,904 CVD deaths in men and 3,874 in women.


The use of calcium supplements correlated with a significantly elevated risk of total CVD mortality, heart disease mortality, and cerebrovascular disease mortality in men. In addition, men taking the highest quintile of calcium supplementation showed an increased risk of CVD death, which was mainly driven by heart disease death, Dr. Xiao and her associates said (JAMA Intern. Med. 2013 [doi:10.1001/jamainternmed.2013.3283]).


In women, null associations were seen between calcium supplements and all of these outcomes.


Dietary calcium showed no relationship with any mortality outcome in men or women.


These findings remained robust in a sensitivity analysis that excluded data on all deaths that occurred during the first 2 years of follow-up.


In analyses that categorized subjects by age, smoking status, BMI, hypertension, hypercholesterolemia, magnesium intake, and alcohol consumption, the positive association between calcium supplements and increased mortality persisted in most of these subgroups among men. It remained null among women except in three notable subgroups: In women who were former smokers, who did not have hypertension, and who had hypercholesterolemia, calcium supplements were linked to an increase in CVD mortality.


One possible mechanism by which calcium supplements could exert an adverse effect on CVD is the deposition of calcium phosphate in cardiovascular structures, in the form of vascular calcification. Increased blood coagulation and arterial stiffness also have been linked to high serum calcium levels, the investigators noted.


The significant interaction by sex was an "intriguing" finding that also deserves further investigation. "It may be reasonable to assume that, on average, male users started taking calcium supplements at an older age. Therefore women were more likely to have achieved calcium balance and stable calcium levels long before the study, and the effect of calcium supplements became less profound," the investigators wrote.


This study was supported by the National Institutes of Health, the National Cancer Institute, and the National Institute on Aging. No financial conflicts of interest were reported.


View on the News
Dietary calcium a safe alternative to supplements


This large, prospective, well-conducted observational study adds to the mounting evidence that calcium supplements may elevate CVD mortality, said Susanna C. Larsson, Ph.D.


"A safe alternative to calcium supplements is to consume calcium-rich foods, such as low-fat dairy foods, beans, and green leafy vegetables, which contain not only calcium but also a cocktail of essential minerals and vitamins," she wrote. This would have additional health benefits, such as improving glycemic control in patients with diabetes, Dr. Larsson added.


Dr. Larsson is in the division of nutritional epidemiology, Institute of Environmental Medicine, at KarolinskaInstitutet, Stockholm. She reported no financial conflicts of interest. These remarks were taken from her invited commentary accompanying Dr. Xiao’s report (JAMA Intern. Med. 2013 [doi:10.1001/jamainternmed.2013.3769]).

  评论这张
 
阅读(62)| 评论(0)
推荐 转载

历史上的今天

在LOFTER的更多文章

评论

<#--最新日志,群博日志--> <#--推荐日志--> <#--引用记录--> <#--博主推荐--> <#--随机阅读--> <#--首页推荐--> <#--历史上的今天--> <#--被推荐日志--> <#--上一篇,下一篇--> <#-- 热度 --> <#-- 网易新闻广告 --> <#--右边模块结构--> <#--评论模块结构--> <#--引用模块结构--> <#--博主发起的投票-->
 
 
 
 
 
 
 
 
 
 
 
 
 
 

页脚

网易公司版权所有 ©1997-2017