Comparison of decline in renal function between patients with chronic hepatitis B with or without antiviral therapy

Summary Background and Aims Renal function can deteriorate in patients with chronic hepatitis B (CHB). We compared the risk of renal function decline between patients with untreated and treated CHB receiving antiviral therapy. Methods This retrospective study included 1061 untreated CHB patients, and 366 on tenofovir alafenamide (TAF), 190 on besifovir dipivoxil maleate (BSV), and 2029 on entecavir (ETV). The primary outcome was renal function decline, a ≥ one‐stage increase in chronic kidney disease for ≥3 consecutive months. Results The incidence and risk of renal function decline were significantly higher in the 1:1 propensity score‐matched treated group (588 pairs) than in the untreated (2.7 per 1000 person–years [PYs] vs. 1.3 per 1000 PYs, adjusted hazard ratio [aHR] = 2.29, all p < 0.001). The matched TAF group (222 pairs) showed a similar risk for the primary outcome (aHR = 1.89, p = 0.107) despite a significantly higher incidence thereof, compared to the untreated (3.9 vs. 1.9 per 1000 PYs, p = 0.042). The matched BSV and untreated groups (107 pairs) showed no significant differences in the incidence and risk. However, ETV users (541 pairs) carried a significantly higher outcome incidence and risk than the matched untreated (3.6 vs. 1.1 per 1000 PYs, aHR = 1.05, all p < 0.001). Compared to each matched untreated group, changes in the estimated glomerular filtration rate over time were greater in the ETV group ( p = 0.010), despite being similar in the TAF ( p = 0.073) and BSV groups ( p = 0.926). Conclusions Compared with untreated patients, TAF or BSV users showed similar risk, whereas ETV users showed a higher risk of renal function decline.