Effect of the addition of thiazolidinedione to sodium-glucose cotransporter 2 inhibitor therapy on lipid levels in type 2 diabetes mellitus: a retrospective study using Korean National Health Insurance Service data

Abstract

Background: Dyslipidemia is common in patients with type 2 diabetes mellitus (T2D) and contributes to an increased risk of cardiovascular disease. Previous studies have shown that treatment with thiazolidinediones (TZDs) and sodium-glucose cotransporter-2 inhibitors (SGLT2-i) may help to improve dyslipidemia in T2D patients. In this study, we investigated whether patients treated with TZD and SGLT2-i showed greater improvement in high-density lipoprotein cholesterol (HDL-C) levels than those treated with only SGLT2-i.Methods: From the National Health Insurance Service database of Korea, we extracted all patients who first received SGTL2-i from 2014 to 2016. Propensity score matching was performed to balance the two groups: group A (SGTL2-i and TZD, regardless of other antidiabetic medications) and group B (SGTL2-i only without TZD, regardless of other antidiabetic medications). Posttreatment HDL-C levels were compared by the Student t-test.Results: In total, 1,400 T2D patients (700 in each group) were matched by propensity score matching. There was a significant posttreatment increase in HDL-C in group A (49.54±20.03 to 51.6±12.92 mg/dL, P=0.007), but not in group B (49.14±13.52 to 49.1±2.15 mg/dL, P=0.937). Group A also showed significantly higher posttreatment HDL-C levels than group B (51.4±12.92 vs. 49.1±12.15 mg/dL, P<0.001). Regarding the secondary endpoints, posttreatment triglyceride levels were lower (P<0.001), but total cholesterol (P=0.131) and low-density lipoprotein cholesterol levels (P=0.054) were not different after treatment.Conclusions: The combination of SGTL2-i and TZD may be more effective in ameliorating dyslipidemia in T2D patients than SGLT2-i alone. However, further studies are needed to confirm this finding.