Pre-exercise basal insulin reduction improves control says study
A reduction in basal insulin of between 50% to 80% performed 90 minutes before physical activity improves blood glucose control and reduces hypoglycaemia risk during exercise in people with type 1 diabetes, new research has found.
To reduce exercise-associated hypoglycaemia, people with the condition on continuous subcutaneous insulin infusion typically perform basal rate reductions (BRRs) and/or increase carbohydrate intake to counter the risk of low blood glucose, but the timing and amount of basal rate reductions (BRRs) necessary to prevent hypoglycaemia are unclear.
This study, published by Diabetes Care, aimed to determine if BRRs set 90 min pre-exercise better attenuate hypoglycaemia compared to pump suspension (PS) at the beginning of physical activity.
It involved 17 participants who completed three 60-min treadmill exercise visits in a randomised crossover design, with the following insulin strategies PS at exercise onset, 80% BRR set 90 minute pre-exercise and 50% BRR set 90 minute pre-exercise.
Summarising the results, the researchers reported: “Blood glucose level at exercise onset was higher with 50% BRR (191 ± 49 mg/dL) vs. 80% BRR (164 ± 41 mg/dL; P < 0.001) and PS (164 ± 45 mg/dL; P < 0.001). By exercise end, 80% BRR showed the smallest drop (−31 ± 58 mg/dL) vs. 50% BRR (−47 ± 50 mg/dL; P = 0.04) and PS (−67 ± 41 mg/dL; P < 0.001). With PS, 7 out of 17 participants developed hypoglycemia versus 1 out of 17 in both BRR conditions (P < 0.05).
“Following a standardized meal postexercise, glucose rose with PS and 50% BRR (both P < 0.05), but failed to rise with 80% BRR (P = 0.16). Based on interstitial glucose, overnight mean percent time in range was 83%, 83%, and 78%, and time in hypoglycemia was 2%, 1%, and 5% with 80% BRR, 50% BRR, and PS, respectively (all P > 0.05).”
They concluded: “Overall, a 50–80% BRR set 90 min pre-exercise improves glucose control and decreases hypoglycaemia risk during exercise better than PS at exercise onset, while not compromising the postexercise meal glucose control.”
To access the study, click here.