Changes in CBC-derived inflammatory indices following dapagliflozin initiation in patients with type 2 diabetes mellitus

Background Type 2 diabetes mellitus (T2DM) is associated with chronic low-grade inflammation, which contributes to metabolic dysfunction and vascular complications. Sodium-glucose co-transporter-2 (SGLT2) inhibitors are used for glycemic control and provide cardiovascular and renal benefits that may involve inflammatory pathways, in part. However, short-term changes in complete blood count (CBC)-derived inflammatory indices after initiating SGLT2 inhibitors remain poorly characterized. This study aimed to assess changes in CBC-derived inflammatory indices, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI), following dapagliflozin initiation in patients with type 2 diabetes mellitus (T2DM). A secondary exploratory objective was to identify demographic and clinical factors potentially associated with statistically significant pre–post changes in the indices. Methods This retrospective study used electronic health record data from adults with T2DM who initiated dapagliflozin in 2023 or 2024. A total of 441 patients met the eligibility criteria for paired baseline and six-month hematological assessments. We assessed changes in neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI). Correlation and multivariable regression analyses examined associations with selected clinical characteristics. Results Significant reductions in NLR (p = 0.039), MLR (p = 0.015), SII (p = 0.034), and SIRI (p = 0.016) were observed six months after dapagliflozin initiation, whereas PLR did not change significantly (p = 0.055). However, the corresponding effect sizes were small (r = 0.098–0.116). All four reductions remained statistically significant following Benjamini–Hochberg false discovery rate adjustment. Exploratory multivariable analyses identified associations between selected clinical comorbidities and changes in inflammatory indices; however, these associations were sensitive to influential observations and were not reproduced in median regression analyses. Conclusions Several CBC-derived inflammatory indices decreased during the six-month period following dapagliflozin initiation in patients with T2DM, suggesting measurable changes in systemic inflammatory status over time. These routinely available indices may provide useful adjunctive information when evaluating inflammatory profiles in patients with T2DM. Further prospective studies with comparator groups and established inflammatory biomarkers are warranted to confirm these findings and clarify their clinical significance.