Causal Relationship between Chronic Hepatitis B and Stroke in East Asians: A Mendelian Randomization Study

Area of Science:

• Genetics
• Epidemiology
• Hepatology

Background:

• Chronic hepatitis B (CHB) and stroke are significant global health burdens, particularly in low- and middle-income countries.
• Existing epidemiological data on the association between CHB and stroke present conflicting results, leaving the causal relationship unclear.

Purpose of the Study:

• To investigate the potential causal effect of chronic hepatitis B (CHB) on stroke and its subtypes in East Asian populations.
• Utilize Mendelian randomization (MR) analysis to assess genetic predispositions for CHB in relation to stroke risk.

Main Methods:

• Employed Mendelian randomization (MR) analysis using genetic variants associated with CHB from a large genome-wide association study (GWAS) in Chinese individuals.
• Analyzed summary statistics for stroke and its subtypes in East Asians from the largest available GWAS data.
• Applied the inverse variance weighting method and supplementary approaches for robust causal effect estimation.

Main Results:

• A statistically significant association was found between genetic predisposition to CHB and a reduced risk of large-artery atherosclerotic stroke (OR = 0.872, P = 0.010).
• No significant causal effects of CHB were observed for other stroke subtypes.
• Analyses indicated no significant evidence of heterogeneity or horizontal pleiotropy, supporting the validity of the findings.

Conclusions:

• This study provides novel genetic evidence suggesting a protective association between chronic hepatitis B (CHB) and large-artery atherosclerotic stroke in East Asian populations.
• The findings contribute to a better understanding of the etiological factors influencing stroke development and highlight potential complex interactions between viral infections and cardiovascular health.