Abstract
AIM: To investigate ethnic differences in the comparative effectiveness of sulfonylureas (SU), dipeptidyl peptidase-4 inhibitors (DPP4i) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) on cardiovascular outcomes. MATERIALS AND METHODS: We identified adults with type 2 diabetes in UK electronic health records initiating SU, DPP4i or SGLT2i (2015-2022). The outcomes were major adverse cardiovascular events (MACE: myocardial infarction, stroke, heart failure hospitalisation, cardiovascular death). Cox models estimated hazard ratios for DPP4i versus SU, SGLT2i versus SU and SGLT2i versus DPP4i. Wald tests assessed interaction by ethnicity. RESULTS: Among 91 116 included individuals (72.3% White, 14.2% South Asian, 6.0% Black), 34.2% initiated an SU, 42.0% DPP4i and 23.8% SGLT2i. There was weak evidence of interaction by ethnicity for DPP4i versus SU on MACE (p = 0.12), with stronger effects observed for DPP4i in the Black group (hazard ratio [HR]: 0.64, 95% confidence interval [CI]: 0.46-0.89) than White (HR: 0.91, 95% CI: 0.84-0.98) or South Asian (HR: 0.93, 95% CI: 0.75-1.16) groups. There was evidence of interaction by ethnicity for DPP4i versus SU on heart failure hospitalisation (p = 0.05), with a stronger effect observed for DPP4i in the Black group (HR: 0.50, 95% CI: 0.30-0.84). There was no clear evidence of ethnic differences for other treatment comparators or cardiovascular outcomes. CONCLUSIONS: We found weak evidence suggesting a greater effect of DPP4i than SUs against MACE in Black people, particularly for heart failure hospitalisation, but no evidence of other ethnic differences in treatment effects.