66-LB: Greater Time Spent in Hypoglycemia during Night Compared with Day during Intensified Training in Professional Cyclists with Type 1 Diabetes—A Prospective Observational Study

Abstract

Aim: To compare time spent in pre-specified glycemic ranges in day and night-time during intensive training in professional cyclists with type 1 diabetes (T1D). Methods: Fifteen male professional cyclists with T1D on multiple daily injections (age 27±4 years, duration T1D 11±5 years, BMI 21.6±1.5 kg·min-2, HbA1c 7.2±0.7%, O2max 73±4 ml·kg·min-1) performed road cycle sessions (50-90% of the anaerobic threshold, duration 1-6 hours) over 9 consecutive days. Time spent in pre-specified glycemic ranges was compared between day and night time using paired t-test and Wilcoxon matched-pairs signed rank test, P≤0.05. Results: Overall glycemia is shown in Figure 1. More time was spent in level 1 (54-70 mg·dl-1) (6±5% vs. 4±3%, P=0.05) and level 2 hypoglycemia (<54 mg·dL-1) (3±5% vs. 1±4%, P=0.002) during night vs. day periods. During daytime, more time was spent in level 2 hyperglycemia (>299 mg dL-1) (night 0.2±0.4% vs. day 1.4±2.3%, P=0.02). Conclusion: Professional cyclists with T1D spent more time in hypoglycemia during the night compared to day-time during intensified training. Long-lasting insulin-sensitizing effects of endurance exercise may suggest a greater need for additional pre-bed carbohydrates and/or insulin dose reductions. Disclosure O. Moser: Research Support; Self; Abbott, Dexcom, Inc., Novo Nordisk A/S. M.L. Eckstein: Research Support; Self; Novo Nordisk A/S. O. McCarthy: None. M. Riddell: Advisory Panel; Self; Xeris Pharmaceuticals, Inc. Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc., Insulet Corporation, Novo Nordisk Inc., Sanofi. Speaker’s Bureau; Self; Medtronic MiniMed, Inc., OmniPod. Stock/Shareholder; Self; Zucara Therapeutics Inc. F.Y. Fontana: None. K. Skroce: None. L. Festa: None. P.H. Lagrou: None. P. Southerland: Other Relationship; Self; Novo Nordisk Inc. M.P. Christiansen: Research Support; Self; Abbott, Biolinq, Dexcom, Inc., Eli Lilly and Company, Janssen Pharmaceuticals, Inc., Medtronic MiniMed, Inc., Novo Nordisk A/S, Sanofi-Aventis, Xeris Pharmaceuticals, Inc. B.W. Bode: Consultant; Self; ADOCIA, Lexicon Pharmaceuticals, Inc., Novo Nordisk Inc. Research Support; Self; Becton, Dickinson and Company, Dexcom, Inc., Diasome Pharmaceuticals, Inc., Eli Lilly and Company, Eyenuk Inc., Insulet Corporation, National Institutes of Health, Novo Nordisk Inc., Sanofi Research & Development, Senseonics, Xeris Pharmaceuticals, Inc. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Janssen Pharmaceuticals, Inc., Novo Nordisk Inc., Sanofi US, Senseonics. Stock/Shareholder; Self; AgaMatrix, Glytec, LLC. C. Stettler: None. S.N. Scott: None. M. Fisher: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Mylan, NAPP Pharmaceuticals Limited, Novo Nordisk A/S. Speaker’s Bureau; Self; Eli Lilly and Company, Sanofi. C.A. Hayes: Other Relationship; Self; Novo Nordisk A/S. R.M. Bracken: None. Funding Novo Nordisk A/S

Improved glycaemic variability and basal insulin dose reduction during a running competition in recreationally active adults with type 1 diabetes—A single-centre, prospective, controlled observational study

“…A recent observational study in professional cyclists with T1D using CGM systems showed that the athletes had good in-race glycaemia, but were prone to hypoglycaemia during post-exercise nighttime period. Similar results were shown in a larger group of professional cyclists with T1D, detailing also a greater risk of nocturnal hypoglycaemia during a training camp [15]. However, as already seen in recreationally active people with T1D, performing an evening-exercise session increases the risk of late-onset nocturnal hypoglycaemia [15,16].…”

“…Similar results were shown in a larger group of professional cyclists with T1D, detailing also a greater risk of nocturnal hypoglycaemia during a training camp [15]. However, as already seen in recreationally active people with T1D, performing an evening-exercise session increases the risk of late-onset nocturnal hypoglycaemia [15,16]. Increased protein levels of insulin independent glucose transporter type 4 (GLUT-4) might be the main trigger for exercise-induced hypoglycaemia [17].…”

“…Furthermore, the running competition did not increase the risk of late-onset hypoglycaemia when compared with pre-competition glycaemia that was also confirmed when glycaemia was stratified for the daytime and nighttime period. Since the running competition was started at around 10 A.M, people with T1D were less prone to late-onset hypoglycaemia and nocturnal hypoglycaemia as compared to previous studies [14][15][16]. Bolus insulin dose was not adapted and carbohydrate intake was unchanged, while the basal insulin dose was reduced by almost 50% on the day before, and on the day of the running competition.…”

Glucose management for exercise using continuous glucose monitoring (CGM) and intermittently scanned CGM (isCGM) systems in type 1 diabetes: position statement of the European Association for the Study of Diabetes (EASD) and of the International Society for Pediatric and Adolescent Diabetes (ISPAD) endorsed by JDRF and supported by the American Diabetes Association (ADA)

“…If exercise was performed at a moderate-to-high intensity and/or for a long duration, then glucose may decrease during the acute post-exercise period, as seen in experimental studies [74,77]. At a glycaemic threshold of 4.4 mmol/l (80 mg/dl) or slightly higher, based on the risk of hypoglycaemia [76], accompanied by a horizontal trend arrow,~10 g of carbohydrates are recommended to be consumed; 15 g of carbohydrates should be consumed if accompanied by a (slight) downward trend arrow; an individual amount of carbohydrates should be consumed if accompanied by rapidly falling downward trend arrows (Table 3) Nocturnal post-exercise period Following an evening or late afternoon exercise session, or an exercise session of high intensity and long duration, people with type 1 diabetes are at an elevated risk of nocturnal hypoglycaemia, as shown in experimental and observational studies [79,80]. Hypoglycaemia typically occurs within 6 to 15 h after exercise, although the risk may remain longer, as seen in children and adolescents, as well as in adults [81,82].…”

Glucose management for exercise using continuous glucose monitoring ( CGM ) and intermittently scanned CGM ( isCGM ) systems in type 1 diabetes: position statement of the European Association for the Study of Diabetes ( EASD ) and of the International Society for Pediatric and Adolescent Diabetes ( ISPAD ) endorsed by Moser1, Riddell2, Eckstein3 et al. 2020Pediatric DiabetesSelf Cite501440View full textAdd to dashboardCite

“…Following an evening or late afternoon exercise session, or an exercise session of high intensity and long duration, people with type 1 diabetes are at an elevated risk of nocturnal hypoglycaemia, as shown in experimental and observational studies [79,80]. Hypoglycaemia typically occurs within 6 to 15 h after exercise, although the risk may remain longer, as seen in children and adolescents, as well as in adults [81,82].…”