Diabetes Modifies the Association between Renal Function and Left Ventricular Ejection Fraction in Heart Failure Patients: A Cross-Sectional Study.

Highlights: Diabetes modifies the relationship between renal function and cardiac systolic performance in heart failure patients.Urea and creatinine showed stronger inverse associations with LVEF among patients with diabetes compared with those without diabetes.No significant modifying effect of diabetes was observed for hemoglobin, and the interaction with eGFR only approached significance.Multivariable models confirmed urea and creatinine as independent predictors of lower LVEF. Background: Heart failure (HF) and chronic kidney disease (CKD) frequently coexist and contribute to poor clinical outcomes, particularly in patients with diabetes mellitus. The modifying effect of diabetes on the association between renal markers and left ventricular ejection fraction (LVEF) remains poorly understood. Objective: We sought to investigate whether diabetes modifies the relationship between renal biomarkers and LVEF in hospitalized patients with HF. Methods: We conducted a cross-sectional analysis involving 112 patients diagnosed with HF who were admitted to a tertiary care hospital. Data were extracted from electronic medical records, including demographic characteristics, comorbidities, laboratory values, and echocardiographic assessments. The primary outcome was LVEF, as determined by transthoracic echocardiography. Renal function was evaluated using serum urea, creatinine, hemoglobin, and the estimated glomerular filtration rate (eGFR). To examine whether the association between these renal markers and LVEF differed based on diabetes status, we fitted multivariable linear regression models including interaction terms between diabetes and each renal marker. All models were adjusted for age, sex, and HF subtype (HFpEF, HFmrEF, or HFrEF). Results: In multivariable models, both urea and creatinine remained significantly associated with LVEF (P=0.007 and P=0.005, respectively). Hemoglobin and eGFR did not show significant main effects in both unadjusted and adjusted models. In the moderation analysis, a significant interaction was found between diabetes and urea (P=0.022). Among patients with diabetes, an increase in urea was associated with a significant reduction in LVEF (P=0.022), whereas the association was attenuated in patients without diabetes. Similarly, the interaction between creatinine and diabetes was significant (β=-13.12; P=0.003). In contrast, the interaction between diabetes and eGFR approached significance (β=0.11; P=0.076). No significant interaction was found for hemoglobin and diabetes (β=-0.70; P=0.67). Conclusion: Diabetes modifies the relationship between renal function and systolic performance in patients with HF. The stronger associations of urea and creatinine with reduced LVEF in individuals with diabetes highlight the importance of tailored risk assessment in the context of cardiorenal-metabolic disease.