Low serum lipid levels, use of statin and cerebral microbleeds: A systematic review and meta-analysis.

Introduction: Previous studies have shown that low serum lipids and statins may be related to cerebral hemorrhage. We made the meta-analysis to evaluate the associations between serum lipid levels or statins treatment and cerebral microbleeds (CMBs) to identify whether the similar correlation also existed.

Method: We comprehensively searched the Medline, Embase, Cochrane library, Web of Science, only included English journal articles, and systematically collected the observational studies and randomized controlled trials (RCTs) from September 1975 to August 2021. Random-effects model was used to pool data. Statistical heterogeneity was assessed by I statistic and chi-square. 11 items checklists recommended by the Agency for Healthcare Research and Quality (AHRQ), Newcastle-Ottawa Scale (NOS), and Cochrane Risk of Bias tool (ROB) were used to evaluate the methodological quality of cross-sectional studies, cohort studies and randomized controlled trial, respectively.

Results: Five cohort studies, two RCTs, and ten cross-sectional studies, including 16,637 subjects and 2663 CMBs patients, were included in our quantitative synthesis. Our study found that after adjusting the covariates, total cholesterol (TC) was significantly inversely correlated with the prevalent CMBs in any location, while total triglycerides (TG) and High-density lipoprotein (HDL) were significantly inversely associated with prevalent deep CMBs. Low-density lipoprotein (LDL) was negatively associated with incident CMBs after adjusted confounders. We did not found statistical differences between statin and CMBs after adjusted covariates.

Conclusion: Serum major lipid (TC TG HDL LDL) levels may be inversely associated with CMBs. Currently, no sufficient evidence proves that statin therapy is the risk factor of CMBs.