584-P: Similar Variability in Pre- and Post-exercise Glucose Levels between Morning-Fasted and Afternoon-Fed Resistance Exercise in Adults with Type 1 Diabetes

Abstract

Background: Exercise increases longevity and decreases the incidence/progression of diabetes-related complications for those with type 1 diabetes (T1D), but it complicates blood glucose management. Understanding variability in blood glucose response to exercise may help guide choices of exercise strategies for people with T1D. Our primary objective was to compare the variability in capillary glucose (CG) response to morning, fasted resistance exercise (AMre), to afternoon post-prandial exercise (PMre). We hypothesized that CG responses would be less variable during morning fasted RE. Methods: Seven participants [4F/3M; mean (SD): age = 29.1 (11.3) yrs; diabetes duration = 19.4 (6.7) yrs; HbA1c = 7.5 (0.7)%] completed a standardized resistance exercise protocol (3 sets of 8 repetitions of seven exercises involving all major muscle groups with 90 seconds between sets) three times in the morning (~7am) while in a fasted state and three times in the afternoon (~5pm) in a fed state. Sessions were performed in a random order with at least 48 hrs between sessions. Participants aimed for close consistency in the timing of the sessions, any associated meals (PMre only) and related insulin adjustments. To determine the intra-individual variability in CG response during AMre and PMre, as well as subsequent 30-minute recovery periods, we performed paired t-tests of the within-participant SD of the change in CG. Results: From the beginning to the end of RE, mean within-participant SD of CG change was 1.2 (0.5) and 1.9 (1.2) mmol/L during AMre and PMre respectively (p=0.08), and 1.2 (0.4) and 1.2 (1.2) mmol/L during subsequent 30-minute recovery periods (p=0.98). Conclusion: For adults with T1D the variability in CG response may be similar between AMre and PMre. More data are needed to clarify these effects. Disclosure R.Mcclure: None. C.J.Nitz: None. J.E.Yardley: Speaker's Bureau; Dexcom, Inc., Abbott. Funding LifeScan