Hebert P R, Gaziano J M, Hennekens C H
Division of Preventive Medicine, Brigham & Women's Hospital, Boston, Mass.
Arch Intern Med. 1995 Jan 9;155(1):50-5.
While blood cholesterol level predicts coronary heart disease, whether there is any association with the risk of stroke is unclear. Some, but not all, observational studies suggest that cholesterol level predicts risk of stroke, particularly ischemic stroke. This hypothesis is attractive because ischemic events constitute the vast majority of all strokes and, like coronary heart disease, involve atherogenic processes.
To investigate whether lipid lowering reduces the risk of stroke, we performed an overview of randomized trials that included more than 36,000 individuals.
The mean reduction in cholesterol level in the treated as compared with the control subjects ranged from 6% to 23%. Those assigned to treatment experienced no significant reduction in all (fatal plus nonfatal) stroke (relative risk, 1.0; 95% confidence interval, 0.8 to 1.2) or fatal stroke (1.1; 0.8 to 1.6).
The confidence interval for fatal stroke is wide, and alternative hypotheses, including either a small protective or harmful effect, cannot be excluded; however, the point estimates are compatible with no benefit of cholesterol lowering on the risk of stroke. Additional large-scale randomized trials assessing total mortality would more definitively address any benefits on stroke, as well as any excess nonvascular causes of mortality, for which risks of cholesterol lowering also remain uncertain.
虽然血液胆固醇水平可预测冠心病，但尚不清楚其与中风风险是否存在关联。一些（而非全部）观察性研究表明，胆固醇水平可预测中风风险，尤其是缺血性中风。这一假说颇具吸引力，因为缺血性事件占所有中风的绝大多数，并且与冠心病一样，都涉及动脉粥样硬化过程。
为了研究降低血脂是否能降低中风风险，我们对纳入36000多名个体的随机试验进行了综述。
与对照组相比，治疗组的胆固醇水平平均降低幅度在6%至23%之间。接受治疗的患者在所有（致命性加非致命性）中风（相对风险，1.0；95%置信区间，0.8至1.2）或致命性中风（1.1；0.8至1.6）方面均未出现显著降低。
致命性中风的置信区间较宽，不能排除包括轻微保护作用或有害作用在内的其他假说；然而，点估计结果表明降低胆固醇对中风风险没有益处。评估总死亡率的其他大规模随机试验将更明确地说明降低胆固醇对中风的任何益处，以及任何额外的非血管性死亡原因，降低胆固醇对这些方面的风险也仍不确定。
