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Aim: Overnight insulin dosing relies on glucose level and evening food intake, although PA also impacts glycemic levels. We assessed associations between antecedent energy expenditure (EE) from PA and nocturnal glycemia in youth with T1D.

Methods: Youth completed 3-day PA logs (PA type, duration, intensity) and wore 3-day masked CGM (iPro™) quarterly for 18 months. We assigned a MET value to PA and calculated EE (kcal/day), using only complete 24-hour days. CGM metrics were calculated for days (6 AM-11:59 PM) and nights (12 AM-5:59 AM) when ≥50% of CGM data were available.

Results: Youth (N=136, 48% male) were ages 8-17 years (M±SD 12.8±2.5), with T1D duration 5.9±3.1 years and daily insulin dose 0.9±0.3 U/kg; 73% used insulin pumps. Median (IQR) PA duration and EE were 60 (10-120) minutes/day and 287 (0-695) kcal/day, respectively. CGM metrics by day/night appear in Table. In partial correlations adjusted for multiple observations/person, higher EE was associated with lower mean glucose (r=-.12, p=.0001), more %time <70 (r=.09, p=.004), and less %time >180 (r=-.09, p=.006) that night. Time in range was unchanged. When youth EE was <80% of their mean EE, they had 3.2% less time <70 (p=.01) and 5.8% more time >180 (p=.03) that night.

Conclusion: In youth with T1D, PA can reduce nocturnal hyperglycemia and increase nocturnal hypoglycemia. These findings can help tailor automated insulin delivery algorithms according to PA.

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Disclosure

R. O. La banca: None. L. K. Volkening: None. K. Milaszewski: Consultant; Self; Lilly USA, LLC. E. Dassau: Consultant; Self; Eli Lilly and Company, Employee; Self; Eli Lilly and Company, Research Support; Self; Dexcom, Inc., Tandem Diabetes Care, Speaker’s Bureau; Self; Dexcom, Inc., Roche Diabetes Care, Stock/Shareholder; Self; Eli Lilly and Company. S. N. Mehta: None. L. M. Laffel: Consultant; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Dexcom, Inc., Dompe, Insulogic LLC, Janssen Pharmaceuticals, Inc., Laxmi Therapeutic Devices, LifeScan, Lilly Diabetes, Medtronic, Provention Bio, Inc.

Funding

National Institutes of Health (K12DK094721, P30DK036836); Iacocca Family Foundation

© 2021 by the American Diabetes Association
2021
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