Improvement in left ventricular ejection fraction and fluid compartment dynamics in patients with heart failure and type 2 diabetes treated with SGLT-2 inhibitors

To evaluate the longitudinal changes in body fluid compartments and their association with cardiac recovery in patients with concomitant heart failure (HF) and type 2 diabetes mellitus (T2DM) receiving sodium-glucose cotransporter-2 (SGLT-2) inhibitor therapy. In this prospective, single-center study, 64 patients diagnosed with both HF and T2DM were initiated on SGLT-2 inhibitor therapy and followed up for 12 months. Clinical and laboratory parameters, along with bioelectrical impedance analysis (BIA), were evaluated at baseline, 6 months, and 12 months. The key analytical parameters included left ventricular ejection fraction (LVEF), NT-proBNP levels, peripheral edema scores, hospitalization rates, and fluid metrics such as total body water (TBW), extracellular water (ECW), intracellular water (ICW), absolute fluid overload (FO), and relative fluid overload (RFO). A statistically significant increase in LVEF was observed during the 12-month follow-up period (p < 0.001). NT-proBNP levels gradually declined (p = 0.002), and significant reductions in peripheral edema scores were recorded by the 12th month (p = 0.018). Heart failure-related hospitalizations decreased markedly (p < 0.001). Throughout the follow-up period, spot urinary sodium levels increased significantly (p < 0.001). No significant longitudinal changes were observed in the TBW, ECW, ICW, or ECW/TBW ratio (p > 0.05). Although an increase in RFO was noted at 12 months (p = 0.012), the primary fluid compartments remained stable. SGLT-2 inhibitor therapy in patients with HF and T2DM is associated with improved cardiac function, reduced myocardial stress, regression of peripheral edema, and a substantial decrease in the hospitalization rate. The absence of measurable changes in total body water suggests that the cardioprotective effects of SGLT-2 inhibitors extend beyond simple volume reduction, potentially involving direct myocardial and metabolic mechanisms.