Relationship between body weight change and glycaemic control with tirzepatide treatment in people with type 2 diabetes: A post hoc assessment of the SURPASS clinical trial programme

AIM: To assess the relationship between HbA1c and body weight reductions with tirzepatide treatment (5, 10 or 15 mg). MATERIALS AND METHODS: HbA1c and body weight data at 40 weeks (SURPASS-1, -2 and -5) and 52 weeks (SURPASS-3 and -4) were analysed by trial. RESULTS: Across the SURPASS clinical trials, HbA1c reductions from baseline were observed in 96%-99%, 98%-99% and 94%-99% of participants treated with tirzepatide 5, 10 and 15 mg, respectively. Moreover, 87%-94%, 88%-95% and 88%-97% of participants, respectively, experienced weight loss associated with HbA1c reductions. Statistically significant associations (correlation coefficients ranging from 0.1438 to 0.3130 across studies; P ≤ .038) between HbA1c and body weight changes were observed with tirzepatide in SURPASS-2, -3, -4 (all doses) and -5 (tirzepatide 5 mg only). CONCLUSIONS: In this post hoc analysis, consistent reductions in both HbA1c and body weight were observed in most participants treated with tirzepatide at doses of 5, 10 or 15 mg. A statistically significant but modest association between HbA1c and body weight change was observed in SURPASS-2, SURPASS-3 and SURPASS-4, suggesting that both weight-independent and weight-dependent mechanisms are responsible for the tirzepatide-induced improvement in glycaemic control.