Background: High intensity exercise-induced hyperglycemia is recognized in T1D clinical guidelines, but its occurrence after high intensity intermittent exercise (HIIE) in acute studies is inconsistent. This meta-analysis aimed to examine the available evidence of BG responses to HIIE in adults with T1D. The secondary aim was to assess the role of prandial status (fasted/fed) , sex (by percentage of female participants ≤ 50, or > 50) , mean age, fitness (VO2peak) , interval duration, and total exercise duration on BG outcomes. We hypothesized that there would be no consistent effect on BG from HIIE, unless examined in the context of participant prandial status.
Methods: We conducted a literature search using keywords related to T1D and HIIE. Studies were required to have a minimum of 6 participants with T1D aged ≥17 years, involving a HIIE intervention, and a pre- and post-exercise measure of BG to be included. Analyses were performed using a general inverse variance statistical method with a random effects model on RevMan5® statistical software and a weighted multiple regression on STATA17® statistical software.
Results: Seventeen interventions from 13 studies were included in the final analysis. A mean overall BG change of -1.4 mmol/L (-3.0, 0.2) was found during exercise albeit with high heterogeneity (I2= 92%) . Fasted exercise increased BG by +1.7 mmol/L (-0.2, 3.6) , while fed exercise decreased BG by -2.6 mmol/L (3.7, -1.5) , with a statistically significant difference between groups (p<0.001) . There were no significant effects from sex (p=0.74) , fitness (p=0.46) , age (p=0.89) , interval duration (p=0.25) or exercise duration (p=0.38) .
Conclusions: The effect of HIIE on BG is inconsistent, but partially explained by prandial status.
R.Mcclure: None. E.Weseen: None. F.Alcántara cordero: None. M.Maldaner: None. S.Hart: None. N.G.Boulé: None. J.E.Yardley: Research Support; Abbott, Dexcom, Inc., LifeScan, Speaker's Bureau; Abbott Diabetes.