Hepatitis B virus (HBV) infection is associated with an increased risk of chronic kidney disease (CKD), according to a new study.
The study included 299,913 adults free of CKD at baseline who underwent health screening examinations from January 2002 to December 2016 in South Korea. In a fully adjusted model, individuals who tested positive for hepatitis B surface antigen (HBsAg) had a significant 11% increased risk of incident CKD compared with those who tested negative, Yun Soo Hong, MD, of the Johns Hopkins University Bloomberg School of Public Health in Baltimore, and colleagues reported in BMC Nephrology. The investigators defined incident CKD as development of an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2 and/or proteinuria.
HBsAG positivity was associated with a significant 23% increased risk of incident proteinuria and a non-significant 11% decreased risk of an eGFR below 60 mL/min/1.73 m2.
The investigators adjusted for age, sex, screening center, baseline eGFR, smoking status, alcohol consumption, education level, physical activity level, and the presence of hypertension, diabetes, and fatty liver disease.
“In this large cohort, HBsAG positive serology was associated with higher risk of incident CKD, and we provide novel evidence that this association was due to a higher incidence of proteinuria in HBsAG positive participants,” the authors concluded. “Our study adds to the growing body of evidence suggesting that chronic HBV infection may be a contributor to the increasing incidence of CKD.”
Of the 299,913 study participants, 11,209 (3.7%) tested positive for HBsAG. These patients were significantly older than those who tested negative (mean 38.2 vs 37.3 years) and more likely to be male (63.7% vs 56.4%). The HBsAG positive group also had a significantly higher proportion of current smokers (25.1% vs 23.6%).
During a mean follow-up duration of 5.6 years (1,673,701 person-years of follow-up), the investigators observed 13,924 incident cases of CKD: 3225 cases of eGFR below 60 mL/min/1.73 m2 and 11,072 cases of proteinuria. The incidence rates of CKD among the HBsAG positive and negative participants were 9.3 and 8.3 per 1000 person-years, respectively.
With respect to study limitations, the authors noted that they used urine dipstick measurements to identify proteinuria, and dipsticks may not be sufficiently sensitive to detect low proteinuria levels. In addition, the investigators pointed out that they defined CKD using a single measurement of eGFR and/or proteinuria, whereas Kidney Disease Outcomes Quality Initiative [KDOQI] guidelines call for abnormalities or markers of damage to be present for at least 3 months.
Dr Hong and colleagues also acknowledged that their study may not have been long enough to assess the effect of HBV infection on reduction in eGFR, “especially since our participants were relatively young and healthy with stable liver function and low prevalence of underlying comorbidities.”
Hong YS, Ryu S, Chang Y, et al. Hepatitis B virus infection and development of chronic kidney disease: a cohort study. BMC Nephrol. 2018;19:353.