Hepatitis B virus infection and decreased risk of stroke: a meta-analysis

Several studies have reported that hepatitis B virus (HBV) infection may decrease the risk of stroke. However, its association is controversial. Thus, we conducted a systematic review and meta-analysis to investigate the relationship between hepatitis B virus (HBV) infection and the risk of stroke. Relevant studies published before May 2017 were identified by searching PubMed, EMBASE, and ISI Web of Science. The relationships between HBV infection and the risk of stroke were assessed using odds ratio (OR)/risk ratio (RR) values and the corresponding 95% confidence intervals (CIs). We used the random effects model proposed by DerSimonian and Laird to quantify the relationship. Five articles, including 834,75 HBV-infected patients and 593,949 uninfected controls, were included in the meta-analysis. The risk of stroke was significantly lower in HBV-infected patients than in uninfected controls (summary OR = 0.78; 95% CI = 0.70-0.86; I = 0%). However, this inverse relationship was only observed in cohort studies (OR = 0.77; 95% CI = 0.69-0.86), rather than cross-sectional study (OR = 1.10; 95% CI = 0.55-2.19). In summary, HBV infection was associated with lower risk of developing stroke.