Glucose requirements to maintain euglycemia after moderate-intensity afternoon exercise in adolescents with type 1 diabetes are increased in a biphasic manner

J Clin Endocrinol Metab. 2007 Mar;92(3):963-8. doi: 10.1210/jc.2006-2263. Epub 2006 Nov 21.


Context: Exercise increases the risk of hypoglycemia in type 1 diabetes.

Objective: This study aimed to investigate how the amount of glucose required to prevent an exercise-mediated fall in glucose level changes over time in adolescents with type 1 diabetes.

Setting: The study took place at a tertiary pediatric referral center.

Design, participants, and intervention: Nine adolescents with type 1 diabetes mellitus (five males, four females, aged 16 +/- 1.8 yr, diabetes duration 8.2 +/- 4.1 yr, hemoglobin A1c 7.8 +/- 0.8%, mean +/- SD) were subjected on two different occasions to a rest or 45 min of exercise at 95% of their lactate threshold. Insulin was administered iv at a rate based on their usual insulin dose, with similar plasma insulin levels for both studies (82.1 +/- 19.0, exercise vs. 82.7 +/- 16.4 pmol/liter, rest). Glucose was infused to maintain euglycemia for 18 h.

Main outcome measures: Glucose infusion rates required to maintain euglcycemia and levels of counterregulatory hormones were compared between rest and exercise study nights.

Results: Glucose infusion rates to maintain stable glucose levels were elevated during and shortly after exercise, compared with the rest study, and again from 7-11 h after exercise. Counterregulatory hormone levels were similar between exercise and rest studies except for peaks in the immediate postexercise period (epinephrine, norepinephrine, GH, and cortisol peaks: 375.6 +/- 146.9 pmol/liter, 5.59 +/- 0.73 nmol/liter, 71.9 +/- 14.8 mIU/liter, and 558 +/- 69 nmol/liter, respectively).

Conclusions: The biphasic increase in glucose requirements to maintain euglycemia after exercise suggests a unique pattern of early and delayed risk for nocturnal hypoglycemia after afternoon exercise.

Publication types

  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Blood Glucose / analysis*
  • Circadian Rhythm
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / metabolism
  • Energy Metabolism / drug effects
  • Exercise / physiology*
  • Female
  • Glucose / administration & dosage*
  • Hormones / blood
  • Humans
  • Hypoglycemia / prevention & control*
  • Infusion Pumps
  • Insulin / blood
  • Male


  • Blood Glucose
  • Hormones
  • Insulin
  • Glucose