Effect of Race on Cardiometabolic Responses to Once-weekly Exenatide: Insights from the Exenatide Study of Cardiovascular Event Lowering (EXSCEL)

Background: To determine whether there were racial differences in short-term cardiometabolic responses to once-weekly exenatide (EQW) in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL).

Methods: EXSCEL enrolled 14,752 patients with type 2 diabetes (hemoglobin A (HbA) 6.5-10.0% [48-86 mmol/mol]) with or without cardiovascular disease who were randomized double-blind to EQW or placebo. Background glucose-lowering/other cardiovascular therapies were unaltered for 6 months post-randomization unless clinically essential, facilitating comparison of EQW-associated effects in 14,665 evaluable participants self-identifying as White (n = 11,113), Asian (n = 1444), Black (n = 870), or Other Race (n = 1,238. Placebo-adjusted 6 month absolute changes in cardiometabolic variables were assessed using generalized linear models.

Results: Mean 6-month placebo-adjusted HbA reductions were similar in the four groups (range 0.54-0.67% [5.9 to 7.3 mmol/mol], P = 0.11 for race×treatment interaction), with no significant difference in Asians (reference) versus other groups after covariate adjustment (all P ≥ 0.10). Six-month placebo-adjusted mean changes in systolic (-1.8 to 0.0 mmHg) and diastolic (0.2 to 1.2 mmHg) blood pressure, serum LDL (- 0.06 to 0.02 mmol/L) and HDL (0.00 to 0.01 mmol/L) cholesterol, and serum triglycerides (-0.1 to 0.0 mmol/L) were similar in the racial groups (P ≥ 0.19 for race×treatment interaction and all P ≥ 0.13 for comparisons of Asians with other races). Resting pulse rate increased more in Asians (4 beats/min) than in other groups (≤ 3 beats/min, P = 0.016 for race×treatment interaction and all P ≤ 0.050 for comparisons of Asians with other races).

Conclusions: Short-term cardiometabolic responses to EQW were similar in the main racial groups in EXSCEL, apart from a greater pulse rate increase in Asians.

Trial Registration: https://clinicaltrials.gov NCT01144338.