人们怀疑针对“坏”胆固醇控制心脏病风险是否明智

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Doubt cast on wisdom of targeting ‘bad’ cholesterol to curb heart disease risk

Date: 日期:August 3, 2020 2020年8月3日Source: 来源:BMJ 英国医学杂志Summary: 摘要:Setting targets for ‘bad’ (LDL) cholesterol levels to ward off heart disease and death in those at risk might seem intuitive, but decades of research have failed to show any consistent benefit for this approach, reveals an analysis of the available data. 为有心脏病和死亡风险的人设定“坏”(低密度脂蛋白)胆固醇水平的目标似乎很直观,但是数十年的研究没有表明这种方法有任何持续的好处,一项对现有数据的分析显示


Setting targets for ‘bad’ (LDL) cholesterol levels to ward off heart disease and death in those at risk might seem intuitive, but decades of research have failed to show any consistent benefit for this approach, reveals an analysis of the available data, published online in BMJ Evidence Based Medicine.

为有心脏病和死亡风险的人设定“坏”(低密度脂蛋白)胆固醇水平的目标看起来似乎很直观,但是几十年的研究并没有显示这种方法有任何一致的好处,一项发表在《 BMJ 循证医学》在线版上的现有数据分析显示。

If anything, it is failing to identify many of those at high risk while most likely including those at low risk, who don’t need treatment, say the researchers, who call into question the validity of this strategy.

如果有什么区别的话,那就是它没能识别出许多高风险人群,而最有可能的是那些低风险人群,他们不需要治疗,研究人员说,他们质疑这种策略的有效性。

Cholesterol-lowering drugs are now prescribed to millions of people around the world in line with clinical guidelines.

根据临床指南,现在世界各地有数百万人使用降胆固醇药物。

Those with poor cardiovascular health; those with LDL cholesterol levels of 190 mg/dl or higher; adults with diabetes; and those whose estimated risk is 7.5% or more over the next 10 years, based on various contributory factors, such as age and family history, are all considered to be at moderate to high risk of future cardiovascular disease.

那些心血管健康状况不佳的人; 低密度脂蛋白胆固醇水平在190毫克/分升或以上的人; 糖尿病患者; 以及根据年龄和家族史等各种促成因素估计风险在未来10年内达到7.5% 或以上的人,都被认为有中度至高度风险患上未来的心血管疾病。

But although lowering LDL cholesterol is an established part of preventive treatment, and backed up by a substantial body of evidence, the approach has never been properly validated, say the researchers.

但是研究人员说,尽管降低低密度脂蛋白胆固醇已经成为预防性治疗的一部分,并且有大量的证据支持,但是这种方法从来没有得到过正确的验证。

They therefore systematically reviewed all published clinical trials comparing treatment with one of three types of cholesterol lowering drugs (statins; ezetimibe; PCSK9) with usual care or dummy drugs (placebo) for a period of at least a year in at-risk patients.

因此,他们系统地回顾了所有已发表的临床试验,比较了三种降胆固醇药物(他汀类药物; 依折替米布; PCSK9)与常规护理药物或假药(安慰剂)治疗高危患者至少一年的疗效。

Each of the 35 included trials was categorised according to whether it met the LDL cholesterol reduction target outlined in the 2018 American Heart Association/American College of Cardiology guidelines.

这35个试验中的每一个都是根据它是否达到了2018年美国心脏协会/美国心脏病学院指南中规定的低密度脂蛋白胆固醇降低目标而分类的。

The researchers then calculated the number of people who would need to be treated in order to prevent one ‘event’, such as a heart attack/stroke, or death, and the reduction in absolute risk in each study that reported significantly positive results.

然后,研究人员计算了需要治疗的人数,以防止一个“事件” ,如心脏病发作/中风,或死亡,以及在每个研究报告显着积极的结果的绝对风险降低。

Their analysis showed that over three quarters of all the trials reported no positive impact on risk of death and nearly half reported no positive impact on risk of future cardiovascular disease.

他们的分析显示,超过四分之三的所有试验报告对死亡风险没有积极影响,近一半报告对未来心血管疾病的风险没有积极影响。

And the amount of LDL cholesterol reduction achieved didn’t correspond to the size of the resulting benefits, with even very small changes in LDL cholesterol sometimes associated with larger reductions in risk of death or cardiovascular ‘events,’ and vice versa.

低密度脂蛋白胆固醇的减少量并不对应于由此产生的益处的大小,即使是极小的低密度脂蛋白胆固醇的变化有时与死亡风险或心血管事件的大幅降低相关,反之亦然。

Thirteen of the clinical trials met the LDL cholesterol reduction target, but only 1 reported a positive impact on risk of death; 5 reported a reduction in the risk of ‘events’.

十三项临床试验达到了低密度脂蛋白胆固醇降低的目标,但只有1项报告对死亡风险有积极影响; 5项报告事件风险降低。

Among the 22 trials that didn’t meet the LDL lowering target, four reported a positive impact on risk of death while 14 reported a reduction in the risk of cardiovascular events.

在22个没有达到低密度脂蛋白降低目标的试验中,4个报告对死亡风险有积极影响,14个报告心血管事件风险降低。

This level of inconsistency was evident for all three types of drugs.

这种程度的不一致在所有三种药物中都很明显。

The researchers acknowledge that some of the 35 trials weren’t designed, or of the size needed, to assess the clinical outcomes included in this analysis.

研究人员承认,在35个试验中,有一些没有设计,或者没有达到所需的规模,来评估这项分析中包含的临床结果。

Nevertheless, they point out that while setting targets for lowering LDL cholesterol based on risk “should prevent cardiovascular events in patients at highest risk while avoiding unnecessary treatment in low-risk individuals. Unfortunately, the risk-guided model performs poorly in achieving these goals.”

然而,他们指出,在根据风险设定降低低密度脂蛋白胆固醇的目标时,“应该预防高风险患者的心血管事件,同时避免对低风险人群进行不必要的治疗。不幸的是,风险导向模型在实现这些目标方面表现不佳。”

Because LDL cholesterol is considered essential for the development of cardiovascular disease, “it seems intuitive and logical to target [it],” say the researchers.

因为低密度脂蛋白胆固醇被认为对心血管疾病的发展至关重要,研究人员说: “把它作为目标看起来既直观又合乎逻辑。”。

But they add: “Considering that dozens of [randomised controlled trials] of LDL-cholesterol reduction have failed to demonstrate a consistent benefit, we should question the validity of this theory.”

但是他们补充说: “考虑到许多降低低密度脂蛋白胆固醇的[随机对照试验]都没有显示出一致的益处,我们应该质疑这个理论的有效性。”

And they conclude: “In most fields of science the existence of contradictory evidence usually leads to a paradigm shift or modification of the theory in question, but in this case the contradictory evidence has been largely ignored, simply because it doesn’t fit the prevailing paradigm.”

他们的结论是: “在大多数科学领域,矛盾证据的存在通常会导致有关理论的范式转变或修改,但在这种情况下,矛盾的证据在很大程度上被忽视了,只是因为它不符合流行的范式。”

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