Longitudinal Changes in Renal, Glycemic, Metabolic, Hematological, and Inflammatory Parameters in Patients with Diabetic Kidney Disease Treated with Empagliflozin or Dapagliflozin: A 12-Month Real-World Cohort Study

Background/ Objectives: Sodium–glucose cotransporter-2 inhibitors (SGLT2i) provide cardiorenal benefits beyond glucose lowering, yet longitudinal changes across multiple laboratory domains in patients with diabetic kidney disease (DKD) remain incompletely characterized. This study aimed to evaluate 12-month changes in renal, glycemic, metabolic, hematological, and inflammatory parameters in patients with DKD treated with empagliflozin or dapagliflozin. Methods: This retrospective, single-center cohort study included 452 patients with type 2 diabetes mellitus and DKD who received empagliflozin or dapagliflozin. Laboratory parameters were assessed at baseline and after 12 months. Longitudinal changes, between-group differences, correlations, and exploratory path analyses were evaluated. Results: Over 12 months, glycated hemoglobin and fasting glucose levels decreased, whereas estimated glomerular filtration rate (eGFR), vitamin D, hematocrit, mean corpuscular volume, and high-density lipoprotein cholesterol (HDL-C) increased. Ferritin, the triglyceride–glucose (TyG) index, bicarbonate, and plateletcrit decreased. Most other measured hematological and inflammatory parameters did not change significantly. The overall patterns of change were broadly similar between treatment groups, although selected differences were observed in individual parameters. In exploratory path analyses, age was negatively associated with change in eGFR (β = −0.269, p < 0.001), whereas KDIGO category was positively associated with change in eGFR (β = 0.200, p < 0.001). Sex was associated with change in the TyG index (β = −0.261, p = 0.013), and treatment group was associated with change in the platelet-to-lymphocyte ratio (β = −0.194, p = 0.010). The models explained a modest proportion of the variance. Conclusions: This real-world cohort provides a multidomain assessment of laboratory changes observed over 12 months in patients with DKD receiving empagliflozin or dapagliflozin. Changes extended beyond glycemic measures to selected renal, metabolic, and hematological parameters, while most conventional and composite inflammatory markers remained unchanged. The observational design and absence of a non-SGLT2i control group preclude causal conclusions or claims of long-term renoprotection. Prospective controlled studies are warranted to clarify the clinical significance and comparative effects of these changes.