Abstract
BACKGROUND: Chronic kidney disease (CKD) progression is shaped not only by biological risk factors but also by social determinants of health. Educational attainment is a key socioeconomic indicator, yet data from Eastern Europe remain limited. METHODS: We conducted a retrospective cohort study including 428 adults with cardio-renal-metabolic (CRM) syndrome having CKD stages G3a-G4 enrolled between 2022 and 2024 and followed until December 2024. Patients were stratified by educational attainment using the International Standard Classification of Education (ISCED 2011): low (ISCED 0-2) vs. high (ISCED 3-8). The primary outcome was a composite of a ≥40% decline in estimated glomerular filtration rate (eGFR) or initiation of kidney replacement therapy (KRT). Secondary outcomes were eGFR slope, doubling of urine albumin-to-creatinine ratio (uACR), and KRT initiation. RESULTS: Of 428 patients, 245 (57.2%) had low education. These patients had lower use of renoprotective therapies. During a median follow-up of 32 months, 88 primary outcome events occurred: 66 (27%) in the low education group vs. 22 (12%) in the high education group. In adjusted analyses, low education remained independently associated with the primary outcome (HR 1.47, 95% CI 1.04-2.36, p = 0.04). The annual eGFR decline was steeper in patients with low education (-3.0 vs. -2.1 mL/min/1.73 m(2)/year, p < 0.001), and doubling of uACR was more frequent (24% vs. 15%, HR 1.47, 95% CI 1.02-2.19, p = 0.02). CONCLUSIONS: In a Romanian CRM-CKD cohort, lower educational attainment was an independent predictor of faster kidney function decline and adverse renal outcomes. Beyond reflecting individual disadvantage, educational status in Eastern Europe highlights systemic inequities in access to nephrology care and therapies. Incorporating education into risk stratification and implementing equity-focused interventions may improve CKD outcomes in disadvantaged populations.