Cholesterol Levels and Risk of Hemorrhagic Stroke

Abstract

Background and Purpose— Cholesterol levels are inconsistently associated with the risk of hemorrhagic stroke. The purpose of this study is to assess their relationships using a meta-analytic approach. Methods— We searched PubMed and Embase for pertinent articles published in English. Only prospective studies that reported effect estimates with 95% confidential intervals (CIs) of hemorrhagic stroke for ≥3 categories of cholesterol levels, for high and low comparison, or for per 1 mmol/L increment of cholesterol concentrations were included. We used the random-effects model to pool the study-specific results. Results— Twenty-three prospective studies were included, totaling 1 430 141 participants with 7960 (5.6%) hemorrhagic strokes. In high versus low analysis, the summary relative risk of hemorrhagic stroke was 0.69 (95% CI, 0.59–0.81) for total cholesterol, 0.98 (95% CI, 0.80–1.19) for high-density lipoprotein cholesterol, and 0.62 (95% CI, 0.41–0.92) for low-density lipoprotein cholesterol. In dose–response analysis, the summary relative risk of hemorrhagic stroke for 1 mmol/L increment of total cholesterol was 0.85 (95% CI, 0.80–0.91), for high-density lipoprotein cholesterol was 1.11 (95% CI, 0.99–1.25), and for low-density lipoprotein cholesterol was 0.90 (95% CI, 0.77–1.05). The pooled relative risk for intracerebral hemorrhage was 1.17 (95% CI, 1.02–1.35) for high-density lipoprotein cholesterol. Conclusions— Total cholesterol level is inversely associated with risk of hemorrhagic stroke. Higher level of low-density lipoprotein cholesterol seems to be associated with lower risk of hemorrhagic stroke. High-density lipoprotein cholesterol level seems to be positively associated with risk of intracerebral hemorrhage.