Albuminuria and Metabolic Dysfunction-Associated Steatotic Liver Disease with Advanced Fibrosis in Primary Care

<b><i>Background:</i></b> Metabolic dysfunction-associated steatotic liver disease (MASLD) and chronic kidney disease (CKD) are linked through the cardiovascular-kidney-metabolic (CKM) health spectrum. This study examines the association between albuminuria and advanced liver fibrosis, both prognostic risk factors for severe kidney and liver outcomes, in patients with MASLD. <b><i>Methods:</i></b> This was a retrospective cross-sectional study of primary care patients with MASLD between 2012 and 2023. Urinary microalbumin-to-creatinine ratio (uACR) was the primary predictor variable and categorized as elevated (≥30 mg/g) or normal (<30 mg/g). The primary outcome was a fibrosis-4 index (FIB-4) at high risk for advanced fibrosis (≥2.67). Bivariate analyses described the cohort overall and by uACR status. Logistic regression models estimated the association of an elevated uACR with a FIB-4 at high risk for advanced fibrosis. <b><i>Results:</i></b> The sample included 463 patients of whom 45% had a uACR ≥30 mg/g and 9% had an FIB-4 ≥2.67. In the unadjusted logistic Firth regression model, uACR ≥30 mg/g was associated with an increased odds of having a high-risk FIB-4 (odds ratio [OR] 2.04; 95% confidence interval [CI] 1.06-3.90). After adjusting for estimated glomerular filtration rate (eGFR), there was no significant association between uACR ≥30 mg/g and a high-risk FIB-4 (OR: 1.73; 95% CI: 0.88-3.39). Using a predictor variable combining uACR and eGFR measures, the unadjusted (OR: 3.83; 95% CI: 1.77-8.25) and adjusted (OR: 2.87; 95% CI: 1.29-6.37) logistic Firth regression models demonstrated an association between ACR ≥30 mg/g and eGFR <59 mL/min with the outcome of a high-risk FIB-4. <b><i>Conclusion:</i></b> Albuminuria and reduced eGFR were associated with measures of advanced fibrosis in primary care patients with MASLD, highlighting the link between CKD and MASLD along the CKM health spectrum.