Early Kidney Dysfunction in Metabolic-Associated Fatty Liver Disease: Is Transient Elastography Useful as a Screening Method?

Introduction: Increasing evidence suggests an association between metabolic-associated fatty liver disease (MAFLD) and CKD. Timely prediction of early kidney dysfunction (EKD) is thus essential in this population although a screening method is not stablished. We aimed to evaluate the role of transient elastography (TE) in predicting EKD in patients with MAFLD.

Materials and methods: A prospective cohort study that included patients with MAFLD scheduled for evaluation was performed between May 2019 and January 2020. Demographic, clinical, and laboratory data and TE parameters were prospectively obtained. EKD was defined as microalbuminuria (urinary albumin-to-Cr ratio 30-300 mg/g) and estimated glomerular filtration rate ≥60 mL/min/1.73 m2. Significant liver fibrosis was defined as liver stiffness measurement (LSM) ≥8.2 kPa.

Results: Of the included 45 patients with MALFD, 53.3% were of female gender with mean age of 53.5 ± 10.9 years. EKD was found in 17.8% of patients. MAFLD patients with EKD were significantly more obese (BMI ≥30) (75.0 vs. 32.4%, p = 0.045) and had significantly higher LSM (8.5 ± 4.1 vs. 5.8 ± 2.2 kPa, p = 0.01). After adjustment of potential confounders for EKD, the presence of liver fibrosis remained a significant predictor of EKD, being associated with a 14.3-fold increased risk of EKD (p = 0.04). The optimal cutoff value of LSM to predict EKD was 6.1 kPa (sensitivity: 85.7%; specificity: 67.6%).

Conclusion: Significant liver fibrosis is associated with a significant increased risk of EKD in patients with MAFLD, regardless of other comorbidities. Higher levels of LSM, particularly >6.1 kPa, alert for timely identification of EKD and associated comorbidities, as well as their control, in order to prevent the development of CKD in the long term.