Is low-dose glucagon needed and effective in preventing fasted exercise-induced hypoglycaemia in type 1 diabetes treated with the MiniMed 780G, an automated insulin delivery system?

AIM

To evaluate and compare the plasma glucose (PG) response during spontaneous fasted morning moderate-intensity exercise with and without injection of subcutaneous glucagon in adults with type 1 diabetes (T1D) treated with an automated insulin delivery (AID) system.

METHODS

Ten adults (four female) with T1D (age 50 [42-67] years, diabetes duration: 22 [14-44] years, HbA1c: 55 [47-69] mmol/mol) treated with the MiniMed™ 780G AID system participated in a proof-of-concept two-period, crossover trial. Fasting participants undertook a 45 min bout of continuous moderate-intensity (~60% V̇O) exercise on a cycle ergometer followed by 1 h of rest. Before exercise, 150-μg glucagon was administered subcutaneously on visit 1 (GLUC) but not on visit 2 (NO-GLUC). Temporary target on the AID was activated 15 min before until 15 min after exercise cessation. Blood samples were taken at 5- and 15-min intervals for measuring PG and biomarkers. Data were analysed using paired t tests or repeated measures ANOVA.

RESULTS

Time in range (3.9-10.0 mmol/L) was 100% on both study visits. No hypoglycaemia (<3.9 mmol/L) occurred in either arm. The GLUC arm had significantly higher mean PG (p = 0.01), area under the PG curve (p = 0.01), coefficient of variation (p < 0.01), peak PG (p = 0.01) and PG at the end of exercise (p < 0.01). No differences in endogenous glucoregulatory hormones were observed between visits.

CONCLUSION

Adults with T1D treated with the MiniMed™ 780G can perform spontaneous fasted moderate-intensity exercise without hypoglycaemia. Therefore, glucagon was not needed for prevention of hypoglycaemia in such situations.