Chronic hepatitis B virus infection and risk of chronic kidney disease: a population-based prospective cohort study of 0.5 million Chinese adults

BACKGROUND: Existing evidence remains inconclusive as to the association between chronic hepatitis B virus (HBV) infection and the risk of chronic kidney disease (CKD). We prospectively examined the association between chronic HBV infection and CKD risk, and the joint associations of HBV infection with established risk factors of several lifestyle factors and prevalent diseases on CKD risk. METHODS: Participants from the China Kadoorie Biobank were enrolled during 2004–2008 and followed up until 31 December 2015. After excluding participants with previously diagnosed CKD, cancer, heart disease, and stroke at baseline, the present study included 469,459 participants. Hepatitis B surface antigen (HBsAg) was qualitatively tested at baseline. Incident CKD cases were identified mainly through the health insurance system and disease and death registries. RESULTS: During a median follow-up of 9.1 years (4.2 million person-years), we documented 4555 incident cases of CKD. Cox regression yielded multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Compared with HBsAg-negative participants, the multivariable-adjusted HR (95% CI) for CKD was 1.37 (1.18, 1.60) for HBsAg-positive participants. The association was stronger in men (HR = 1.77; 95% CI: 1.43, 2.20) than in women (HR = 1.10; 95% CI: 0.88, 1.36). HBsAg-positive participants, with or without hepatitis or cirrhosis, whether or not under treatment, all showed increased risk of developing CKD. We observed positive additive interactions of HBsAg positivity with smoking, physical inactivity, or diabetes on CKD risk. Compared with HBsAg-negative participants who were nonsmokers, more physically active, or did not have diabetes at baseline, the greatest CKD risk for HBsAg-positive participants was for those who were smokers (HR = 1.85; 95% CI: 1.44, 2.38), physically inactive (HR = 1.91; 95% CI: 1.52, 2.40), or diabetic (HR = 6.11; 95% CI: 4.47, 8.36). CONCLUSIONS: In countries with a high endemicity of HBV infection, kidney damage associated with chronic HBV infection should be a non-negligible concern. Our findings also highlight the importance of health advice on quitting smoking, increasing physical activity, improving glucose control, and early screening for CKD in people with chronic HBV infection. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12916-018-1084-9) contains supplementary material, which is available to authorized users.