Aims
Preventing post-exercise hypoglycaemia in individuals with Type 1 diabetes (T1D) is challenging with no clear guidelines to prevent hypoglycaemia after exercises of different intensities. The aim of this study was to explore glycaemic profiles over 24 hours following exercise of different intensities in individuals with T1D in a free-living setting.
Methods
This study was a secondary analysis of data collected in individuals with T1D, as part of a larger lab-based four-arm randomised counterbalanced study examining the carbohydrate requirements to maintain euglycaemia for different exercise intensities. Eight participants with T1D (mean±SD age 25.1±5y; HbA1c 7.9±0.8%) receiving continuous subcutaneous insulin infusion, were tested on four separate occasions, on cycle ergometers for up to 40 min at four exercise intensities (VO2peak of 35%,50%,65%,80%). Data from continuous glucose monitoring system for 24 hours post-exercise were analysed using paired t-tests and Wilcoxon signed-rank tests. The outcomes of this study were the percentage of time spent in range (TIR) and rate of prevented or actual hypoglycaemic events in the 24 hours post-exercise.
Results
The percentage of TIR at 35%, 50%, 65% and 80%VO2peak were 50.77±23.01%, 60.44±17.74%, 53.55±23.91% and 57.15±15.07% respectively with no statistical differences across intensities being detected (p≥0.05). The mean rate of prevented or actual hypoglycaemic events/day for exercise at 35%, 50%, 65% and 80%VO2peak were 3.01 (95% CI: 1.72, 4.88), 3.13 (95% CI: 1.89, 4.94), 2.51 (95% CI: 1.29, 4.38) and 3.43 (95% CI: 1.96, 5.58) respectively with no differences between groups.
Conclusion
There was no difference in hypoglycaemic events 24 hours following exercise of four intensities. The small sample size and missing data might have diminished the ability of the study to detect effects of exercise. Our data can be used for further research to design an adequately powered study to determine the effect of exercise intensity on glycaemic control.