No effects of dapagliflozin, metformin or exercise on plasma glucagon concentrations in individuals with prediabetes: A post hoc analysis from the randomized controlled PRE-D trial

Aim: To assess the effects of dapagliflozin, metformin and exercise treatment on changes in plasma glucagon concentrations in individuals with overweight and HbA1c-defined prediabetes. Materials and Methods: One-hundred and twenty individuals with overweight (body mass index ≥ 25 kg/m²) and prediabetes (HbA1c of 39-47 mmol/mol) were randomized to a 13-week intervention with dapagliflozin (10 mg once daily), metformin (850 mg twice daily), exercise (30 minutes of interval training 5 days per week) or control (habitual living). A 75-g oral glucose tolerance test (OGTT) (0, 30, 60 and 120 minutes) was administered at baseline, at 13 weeks (end of intervention) and at 26 weeks (end of follow-up). Linear mixed effects models with participant-specific random intercepts were used to investigate associations of the interventions with fasting plasma glucagon concentration, insulin/glucagon ratio and glucagon suppression during the OGTT. Results: At baseline, the median (Q1; Q3) age was 62 (54; 68) years, median fasting plasma glucagon concentration was 11 (7; 15) pmol/L, mean (SD) HbA1c was 40.9 (2.3) mmol/mol and 56% were women. Compared with the control group, fasting glucagon did not change in any of the groups from baseline to the end of the intervention (dapagliflozin group: −5% [95% CI: −29; 26]; exercise group: −8% [95% CI: −31; 24]; metformin group: −2% [95% CI: −27; 30]). Likewise, there were no differences in insulin/glucagon ratio and glucagon suppression during the OGTT between the groups. Conclusions: In individuals with prediabetes, 13 weeks of treatment with dapagliflozin, metformin or exercise was not associated with changes in fasting or post-OGTT glucagon concentrations.