Investigating the Association between Steatotic Liver Disease and CKD in a Nationally Representative Sample.

Background: Steatotic liver disease (SLD) and chronic kidney disease (CKD) are common conditions that are strongly associated. Yet, there is a paucity of data regarding the prevalence of this overlap and the factors that may drive its occurrence.

Methods: Using the National Health and Nutrition Examination survey, we examined trends among adult participants from 2005 - 2020 that defined SLD with the Fatty Liver Index. We completed correlative analyses among adult participants from 2017 - 2020 that defined SLD based on FibroScan results. We utilized multivariable survey-weighted binomial generalized linear models to determine the factors that were associated with CKD, defined as eGFR <60 or urine albumin-creatinine-ratio >30.

Results: Among the 76,496 participants included in the trend analyses, the estimated prevalence of CKD was 15.7% (95%CI 15.2 - 16.2%) and SLD was 42.3% (95%CI 41.4 - 43.2%). As compared to those without SLD, those with SLD had a significantly higher estimated prevalence of CKD (SLD: 15.7%, 95%CI 14.9 - 16.5% v. No SLD 11.2%, 95%CI 10.7 - 11.7%). In multivariate analyses of 3,667 participants who underwent FibroScan and had SLD by Fatty Liver Index, adjusting for control and presence of DM, HTN, and HLD, compared to those with normal liver stiffness, those with moderate scarring (F2) had similar odds of CKD (1.53, 95CI 0.91-2.56), those with severe scarring (F3) had higher odds of CKD (2.28, 95CI 1.20-4.32), and those with cirrhosis had higher odds of CKD (2.21, 95CI 1.13-4.32).

Conclusions: Our findings highlight that CKD is common among patients with SLD and that higher degrees of hepatic fibrosis are associated with CKD, independent of other co-morbidities of the metabolic syndrome.