Demographic Profile of Patients with Nonalcoholic Fatty Liver Disease (NAFLD) and Proteinuria: A TriNetX-Based Analysis Supporting Targeted CKD Screening

Background: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver condition in the United States and is increasingly recognized for its association with chronic kidney disease (CKD). Proteinuria is a key early marker of CKD, but little is known about the demographic profile of patients who present with both NAFLD and proteinuria. This study aimed to characterize these individuals using real-world data to inform population-specific CKD screening strategies. Methods: We conducted a retrospective cohort study using TriNetX, a national federated electronic health record (EHR) platform. Adults aged ≥18 years with a diagnosis of NAFLD (ICD-10-CM K76.0) and evidence of proteinuria formed Cohort A. Proteinuria was defined by ICD-10-CM R80 or abnormal laboratory criteria: urine albumin-to-creatinine ratio (uACR) ≥30 mg/mmol, urine protein-to-creatinine ratio (uPCR) ≥0.03 g/mmol, or dipstick protein ≥30 mg/dL. Cohort B included patients with proteinuria and no diagnosis of NAFLD. Individuals with ESRD, dialysis dependence, alcoholic liver disease, chronic viral hepatitis, or liver transplantation were excluded. Demographic variables were compared using independent sample t-tests and two-proportion z-tests (p < 0.05) Results: Cohort A included 8,268 patients across 21 healthcare organizations; Cohort B included 1,515,513 patients across 69 sites. The mean age was slightly higher in Cohort A (61.1 ± 15.9 vs. 60.3 ± 20.3 years, p < 0.001). Male sex was more common in the NAFLD group (50.0% vs. 45.5%, p < 0.001), while females predominated in the non-NAFLD cohort (52.8%, p < 0.001). Hispanic ethnicity was significantly more prevalent in the NAFLD cohort (15.3% vs. 10.7%, p < 0.001). Racial distribution also differed, with a higher proportion of White patients in Cohort A (67.8% vs. 61.3%, p < 0.001), and lower representation of Asian and unknown race categories (both p < 0.001) Conclusion: Patients with NAFLD and proteinuria demonstrate a distinct demographic profile, with overrepresentation of male and Hispanic individuals. These findings suggest the need for demographic-specific strategies to enhance early detection of CKD in NAFLD populations. Incorporating routine CKD screening in NAFLD management pathways may help address disparities and enable timely intervention in high-risk subgroups.