Low-Density Lipoprotein Cholesterol Reductions of not Less Than 60 mg/dL Prevent Hemorrhagic Stroke in Hypertensive Populations: A Meta-analysis.

BACKGROUND

The association between low-density lipoprotein cholesterol (LDL-C) levels and the risk of hemorrhagic stroke (HS) detected through different blood pressure statuses remains unclear. Hence, we systematically evaluated the association between LDL-C and HS in populations with and without hypertension.

METHODS

We searched PubMed, Cochrane Library, and Embase databases for articles written in English. Only prospective design or randomized controlled trials (RCTs) reporting effect estimates with 95% confidence intervals (CIs) for the relationship between LDL-C and HS were included. We pooled risk ratios (RRs) stratified by blood pressure status and dose-response analyses with a two-stage generalized least squares for trend estimation (GLST) model. Finally, we compared the lower and optimal groups to find the effect of very low LDL-C levels on the risk of HS.

RESULTS

We included seven randomized controlled trials and 9 prospective cohort studies involving 304,763 participants with 2125 (0.70%) HS events. The non-linear trend suggested that LDL-C levels of approximately 80 mg/dL among hypertensive patients and 115 mg/dL among non-hypertensive patients had the lowest risk of HS. Meanwhile, continually lowering LDL-C levels under the optimal (80 mg/dL for hypertensive patients and 115 mg/dL for non- hypertensive patients) LDL-C level would increase the risk of HS in the hypertensive population (RR = 1.84, 95% CI: 1.36-2.50) but not in the non-hypertensive population (RR = 1.15, 95% CI: 0.97-1.36).

CONCLUSIONS

The risk of HS can be effectively reduced by controlling LDL-C levels to 60-80 mg/dL in the hypertensive population and 115 mg/dL in the non-hypertensive population. The safety range of controlling LDL-C levels to protect against HS among hypertensive patients is narrower than that among the non-hypertensive population. Additionally, controlling blood pressure might play a positive role in safeguarding against HS by lowering LDL-C levels.