294-OR: Type 1 Diabetes Patients with Residual Beta-Cell Function Display Improved Time in Euglycemia and Less Glycaemic Fluctuation after Exercise

Abstract

Aims: Exercise can disrupt glycemia in individuals with type 1 diabetes (T1D). A large inter-individual variability in the glucose responses to exercise exists. It is not known how residual beta-cell function in long duration T1D influences glycaemia around exercise. Methods: Individuals with T1D completed a postprandial urine C-peptide creatinine ratio test (UCPCR), and 25 participants (M/F 14/11, 39.4±12.4 years, HbA1c 58.8±9.3 mmol/mol-1, BMI 25.6±4.0 kg/m2, diabetes duration 21.4±13.7 years) with a range of UCPCR were recruited. Participants were split into undetectable, microsecretors and clinically significant C-peptide groups (<0.001, 0.001-0.2 and >0.2 nmol/mmol, respectively). After a maximum exercise test, participants attended the second visit whereby they completed 45 minutes of walking at 60%VO2peak. Participants then left the laboratory, with the remainder of the trial under free-living control. Blinded continuous glucose monitoring (CGM) was captured for 12 hours before exercise and for 3 days afterwards. Data (mean±SD) were analysed by one way ANOVA with significance accepted at p ≤0.05. Results: CGM data were successfully captured for 22/25 participants. In the 12 hours prior to exercise, there was no significant differences in CGM between groups. In the first 12 hours post-exercise, the clinical C-peptide group spent significantly more time (83.7±23.2%) in time in euglycemia (3.9-10 mmol/l) compared to the microsecretors (38.8±16.9%, p =0.002) and undetectable participants (40.5±23.3%, p =0.005). The clinical group had lower post exercise SD (1.95±1.26) than the microsecretors (3.56±1.09 p =0.045) and tended to be lower than the undetectable (3.54±1.10 p =0.07). Conclusion: Residual beta-cell function may offer protection against exercise induced dysglycemia. C-peptide could potentially be a method of stratifying the amount of exercise related support patients need to manage glucose around exercise. Disclosure G.S. Taylor: None. K. Smith: None. J. Scragg: None. A. Bashir: None. R.A. Oram: Other Relationship; Self; Randox Laboratories Ltd. T.J. McDonald: None. E.J. Stevenson: None. J.A. Shaw: Advisory Panel; Self; Sanofi. Other Relationship; Self; Novo Nordisk A/S. D.J. West: Research Support; Self; Arla Foods Ingredients, Dexcom, Inc. Funding Diabetes Research & Wellness Foundation