Published online Jun 21, 2019. doi: 10.3748/wjg.v25.i23.2961
Peer-review started: March 22, 2019
First decision: April 4, 2019
Revised: April 27, 2019
Accepted: May 8, 2019
Article in press: May 8, 2019
Published online: June 21, 2019
Tenofovir (TDF) and entecavir (ETV) are preferred first-line treatments for chronic hepatitis B (CHB). The long-term safety issue of nucleos(t)ide analog is very important because CHB patients should take it indefinitely. In addition, a number of researchers have recently reported many CHB patients suffer from CKD through large-scale studies.
Over the years, several studies have been conducted to compare renal safety of the two drugs, but the results varied and sometimes conflicted with each other. Confusedly, the recom-mendations of the recent two guidelines are contradictory.
We aimed to conduct a systematic review and meta-analysis to assess renal safety of TDF and ETV in patients with CHB using continuous variables.
Calculating the change of creatinine and estimated glomerular filtration rate (eGFR), we secured the distinction from the prior meta-analysis that using dichotomous data. To enhance the clinical importance, we performed sensitivity analysis with meta-regression.
With nine NRSs, we conducted meta-analysis. Changes in creatinine levels were higher in the TDF group than in the ETV group at 6 mo [mean difference (MD) = 0.03 mg/dL; 95%CI: 0.02-0.04; I2 = 0%], 12 mo (MD = 0.05 mg/dL; 95%CI: 0.02 to 0.08; I2 = 78%), and 24 mo (MD = 0.07 mg/dL; 95%CI: 0.01-0.13; I2 = 93%). The change in eGFR was significantly higher in the TDF group than in the ETV group at 6 mo [standardized mean difference (SMD) = -0.22; 95%Cl: -0.36--0.08; I2 = 0%], 12 mo (SMD = -0.24; 95%Cl: -0.43 to -0.05; I2 = 50%), and 24 mo (-0.35; 95%Cl: -0.61--0.09; I2 = 67%).
Until now, in studies comparing the effect on renal function between the two drugs, the di-fferences varied greatly. However, our study found that the difference was negligible.
The value of creatinine and eGFR in our meta-analysis was a secondary outcome in most of the included studies. And most of the studies used various eGFR formula and different AKI definitions. We need further research comparing renal function as a primary outcome and using universal definition of AKI, if possible, through large-scale RCT.