Cholesterol reduction and stroke occurrence: an overview of randomized clinical trials.

We performed a meta-analysis of randomized clinical trials of more than 6 months duration to describe how fatal and nonfatal strokes are related to cholesterol lowering and to the type of intervention. A total of 41 individual trials including approximately 80,000 subjects and followed for an average of about 4 years were included in the overview. There was a 16% (95% CI, 7-25%) reduction in risk of stroke among treated patients compared to control patients (test for heterogeneity, p = 0.76). When trials that used different interventions were separately examined, a significant reduction in stroke occurrence was observed only for those using statins as active treatment (risk reduction 23%; 95% CI 13-33%). A variance-weighted regression analysis of the logarithmic odds ratios for stroke incidence against the percentage of cholesterol reduction indicated that a reduction of fatal and nonfatal stroke can be obtained for a cholesterol reduction of 9% (95% CI 6.8-13.6%). The combined data of primary and secondary prevention trials indicate that a large reduction of blood cholesterol, achievable with statin drugs, can reduce the incidence of stroke. Copyright 2000 S. Karger AG, Basel.