TY - JOUR
T1 - Insulin pump basal adjustment for exercise in type 1 diabetes
T2 - a randomised crossover study
AU - McAuley, Sybil A.
AU - Horsburgh, Jodie C.
AU - Ward, Glenn M.
AU - La Gerche, André
AU - Gooley, Judith L.
AU - Jenkins, Alicia J.
AU - MacIsaac, Richard J.
AU - O’Neal, David N.
N1 - Funding Information:
This project was funded by grants from the Australian Diabetes Society ADS-Sanofi Diabetes Research Grant programme, the Medical Research & Technology in Victoria programme supported by The Hugh DT Williamson Foundation, and the Lynne Quayle Charitable Trust Fund managed by Equity Trustees. SAM is supported by a University of Melbourne postgraduate scholarship. ALG is supported by a Career Development Scholarship from the National Health and Medical Research Council and a Future Leaders Fellowship from the National Heart Foundation of Australia. AJJ is supported by a Sydney Medical School Fellowship from the University of Sydney.
Publisher Copyright:
© 2016, Springer-Verlag Berlin Heidelberg.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Aims/hypothesis: The aim of this study was to investigate the effects of exercise, vs rest, on circulating insulin and glucose, following pre-exercise insulin pump basal rate reduction. Methods: This was an open-label, two-stage randomised crossover study of 14 adults (seven women, seven men) with type 1 diabetes established on insulin pump therapy. In each stage, participants fasted and insulin delivery was halved following a single insulin basal rate overnight. Exercise (30 min moderate-intensity stationary bicycle exercise, starting 60 min post-basal reduction) and rest stages were undertaken in random order at a university hospital. Randomisation was computer-generated, and allocation concealed via sequentially numbered sealed opaque envelopes. Venous blood was collected at 15 min intervals from 60 min pre- until 210 min post-basal rate reduction. Changes in plasma free insulin (the primary outcome), and changes in plasma glucose, with exercise were compared with changes when resting. Outcomes were assessed blinded to group assignment. Results: Following basal rate reduction when rested, mean (± SE) free insulin decreased by 4.9 ± 2.9%, 16.2 ± 2.6% and 18.6 ± 3.2% at 1, 2 and 3 h, respectively (p < 0.05 after 75 min). With exercise, relative to rest, mean free insulin increased by 6 ± 2 pmol/l after 15 min and 5 ± 2 pmol/l after 30 min (p < 0.001), then declined post-exercise (p < 0.001). Three participants (mean baseline glucose 5.0 ± 0.1 mmol/l) required glucose supplementation to prevent or treat exercise-related hypoglycaemia. In the other 11 participants (mean baseline glucose 8.4 ± 0.5 mmol/l), glucose increased by 0.8 ± 0.3 mmol/l with exercise (p = 0.028). Conclusions/interpretation: Halving the basal insulin rate 1 h prior to exercise did not significantly reduce circulating free insulin by exercise commencement. Exercise itself transiently increased insulin levels. In participants with low-normal glucose pre-exercise, hypoglycaemia was not prevented by insulin basal rate reduction alone. Greater insulin basal rate reduction and supplemental carbohydrate may be required to prevent exercise-induced hypoglycaemia. Trial registration: ANZCTR.org.au
AB - Aims/hypothesis: The aim of this study was to investigate the effects of exercise, vs rest, on circulating insulin and glucose, following pre-exercise insulin pump basal rate reduction. Methods: This was an open-label, two-stage randomised crossover study of 14 adults (seven women, seven men) with type 1 diabetes established on insulin pump therapy. In each stage, participants fasted and insulin delivery was halved following a single insulin basal rate overnight. Exercise (30 min moderate-intensity stationary bicycle exercise, starting 60 min post-basal reduction) and rest stages were undertaken in random order at a university hospital. Randomisation was computer-generated, and allocation concealed via sequentially numbered sealed opaque envelopes. Venous blood was collected at 15 min intervals from 60 min pre- until 210 min post-basal rate reduction. Changes in plasma free insulin (the primary outcome), and changes in plasma glucose, with exercise were compared with changes when resting. Outcomes were assessed blinded to group assignment. Results: Following basal rate reduction when rested, mean (± SE) free insulin decreased by 4.9 ± 2.9%, 16.2 ± 2.6% and 18.6 ± 3.2% at 1, 2 and 3 h, respectively (p < 0.05 after 75 min). With exercise, relative to rest, mean free insulin increased by 6 ± 2 pmol/l after 15 min and 5 ± 2 pmol/l after 30 min (p < 0.001), then declined post-exercise (p < 0.001). Three participants (mean baseline glucose 5.0 ± 0.1 mmol/l) required glucose supplementation to prevent or treat exercise-related hypoglycaemia. In the other 11 participants (mean baseline glucose 8.4 ± 0.5 mmol/l), glucose increased by 0.8 ± 0.3 mmol/l with exercise (p = 0.028). Conclusions/interpretation: Halving the basal insulin rate 1 h prior to exercise did not significantly reduce circulating free insulin by exercise commencement. Exercise itself transiently increased insulin levels. In participants with low-normal glucose pre-exercise, hypoglycaemia was not prevented by insulin basal rate reduction alone. Greater insulin basal rate reduction and supplemental carbohydrate may be required to prevent exercise-induced hypoglycaemia. Trial registration: ANZCTR.org.au
KW - Exercise
KW - Hypoglycaemia
KW - Insulin pump
KW - Type 1 diabetes
UR - https://www.scopus.com/pages/publications/84966709240
U2 - 10.1007/s00125-016-3981-9
DO - 10.1007/s00125-016-3981-9
M3 - Article
C2 - 27168135
AN - SCOPUS:84966709240
SN - 0012-186X
VL - 59
SP - 1636
EP - 1644
JO - Diabetologia
JF - Diabetologia
IS - 8
ER -
SDG 3 Good Health and Well-being