MAFLD and risk of CKD

Whereas nonalcoholic fatty liver disease (NAFLD) is a multisystem disease, the association between metabolic dysfunction-associated fatty liver disease (MAFLD) and extra-hepatic diseases is not known. The aim of this cross-sectional study was to compare the prevalence of chronic kidney disease (CKD) in patients with either MAFLD or NAFLD, and then to examine the association between the presence and severity of MAFLD and CKD and abnormal albuminuria.

A total of 12,571 individuals with complete biochemical and liver ultrasonography data from the Third National Health and Nutrition Examination Survey (1988-1994) were included in the analysis. Multivariable logistic regression analyses were performed to test the independence of associations between MAFLD or MAFLD severity as the key exposures and CKD (defined as either CKD stage ≥1 or stage ≥3) or abnormal albuminuria (urinary albumin-to-creatinine ratio ≥ 3 mg/mmol) as the outcomes.

The prevalence of MAFLD and NAFLD was 30.2% (n = 3794) and 36.2% (n = 4552), respectively. MAFLD individuals had a lower eGFR (74.96 ± 18.21 vs. 76.46 ± 18.24 ml/min/1.73 m², P < 0.001) and a greater prevalence of CKD (29.60% vs. 26.56%, P < 0.05) than NAFLD individuals. Similarly, there was a higher prevalence CKD in MAFLD than in non-metabolic dysfunction-associated NAFLD (P < 0.05). Notably, after adjustment for sex, age, ethnicity, alcohol intake and diabetes, the severity of MAFLD (i.e. NAFLD fibrosis score ≥ 0.676) was associated with 1.34-fold higher risk of prevalent CKD (P < 0.05).

MAFLD identifies patients with CKD better than NAFLD. MAFLD and MAFLD with increased liver fibrosis score are strongly and independently associated with CKD and abnormal albuminuria.