Chronic HBV infection may up risk of intracerebral haemorrhage

Chronic hepatitis B virus (HBV) infection appears to put Chinese adults at higher risk of intracerebral haemorrhage (ICH) but not other stroke subtypes, as reported in a study.

For the study, researchers used data from the China Kadoorie Biobank, which included more than 500,000 adults who were 30–79 years of age and were recruited from five urban and five rural areas in China. At baseline, 3.0 percent of the participants were positive for hepatitis B surface antigen (HBsAg).

Over 11 years of follow-up, a total of 59,117 incident stroke cases were documented, including 11,318 ICH, 49,971 ischemic stroke, 995 subarachnoid haemorrhage, and 3,036 other/unspecified stroke.

Cox regression models showed that HBsAg positivity was associated with a heightened risk of ICH (adjusted hazard ratio [HR], 1.29, 95 percent confidence interval [CI], 1.16–1.44), both fatal (n=5,982; adjusted HR, 1.36, 95 percent CI, 1.16–1.59) and nonfatal (n=5,336; adjusted HR, 1.23, 95 percent CI, 1.06–1.44).  

Meanwhile, HBsAg positivity showed no significant associations with risks of ischaemic stroke (adjusted HR, 0.97, 95 percent CI, 0.92–1.03), subarachnoid haemorrhage (adjusted HR, 0.87, 95 percent CI, 0.57–1.33), or other/unspecified stroke (adjusted HR, 1.12, 95 percent CI, 0.89–1.42).

In a subset of 17,833 participants, those who were HBsAg-positive had lower lipid and albumin levels and higher liver enzyme levels compared with HBsAg-negative participants. Analysis adjusted for liver enzymes and albumin attenuated the association between ICH from HBsAg positivity (HR, 1.15, 95 percent CI, 0.90–1.48), suggesting possible mediation by abnormal liver function.