Advanced liver fibrosis measured by transient elastography predicts chronic kidney disease development in individuals with non-alcoholic fatty liver disease.

AIMS/HYPOTHESIS: Non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) are progressive chronic conditions that share important cardiometabolic risk factors and pathogenic mechanisms. We investigated the association between liver fibrosis measured by transient elastography (TE) and the risk of incident CKD in individuals with NAFLD.
METHODS: A total of 5983 participants with NAFLD (defined as controlled attenuation parameter >222 dB/m) but without CKD who underwent TE between March 2012 and August 2018 were selected. The primary outcome was incident CKD, defined as the occurrence of eGFR <60 ml min-1 [1.73 m]-2 or proteinuria (≥1+ on dipstick test) on two consecutive measurements during follow-up. The secondary outcome was a 25% decline in eGFR measured on two consecutive visits.
RESULTS: The mean age was 51.8 years and 3756 (62.8%) participants were male. During 17,801 person-years of follow-up (mean follow-up of 3.0 years), 62 participants (1.0%) developed incident CKD. When stratified into TE-defined fibrosis stages (F0-F4), multivariable Cox models revealed that risk of incident CKD was 5.40-fold (95% CI 2.46, 11.84; p < 0.001) higher in the F3/F4 group (≥9.5 kPa) than in the F0 group (<5.5 kPa). During 17,577 person-years of follow-up (mean follow-up of 3.0 years), 201 participants (3.4%) experienced the secondary outcome, for which the F3/F4 group had a 3.22-fold higher risk (95% CI 1.96, 5.28; p < 0.001) than the F0 group. CONCLUSIONS/
INTERPRETATION: In this large cohort of individuals with NAFLD but without baseline CKD, advanced liver fibrosis measured by TE was significantly associated with a higher risk of incident CKD.