The effects of aerobic exercise on glucose and counterregulatory hormone concentrations in children with type 1 diabetes.
OBJECTIVE
To examine the acute glucose-lowering effects of aerobic exercise in children and adolescents with type 1 diabetes.


METHODS
Fifty children and adolescents with type 1 diabetes (ages 10 to <18 years) were studied during exercise. The 75-min exercise session consisted of four 15-min periods of walking on a treadmill to a target heart rate of 140 bpm and three 5-min rest periods. Blood glucose and plasma glucagon, cortisol, growth hormone, and norepinephrine concentrations were measured before, during, and after exercise.


RESULTS
In most subjects (83%), plasma glucose concentration dropped at least 25% from baseline, and 15 (30%) subjects became hypoglycemic (< or = 60 mg/dl) or were treated for low glucose either during or immediately following the exercise session. The incidence of hypoglycemia and/or treatment for low glucose varied significantly by baseline glucose, occurring in 86 vs. 13 vs. 6% of subjects with baseline values <120, 120-180, and >180 mg/dl, respectively (P < 0.001). Exercise-induced increases in growth hormone and norepinephrine concentrations were marginally higher in subjects whose glucose dropped < or = 70 mg/dl. Treatment of hypoglycemia with 15 g of oral glucose resulted in only about a 20-mg/dl rise in glucose concentrations.


CONCLUSIONS
In youth with type 1 diabetes, prolonged moderate aerobic exercise results in a consistent reduction in plasma glucose and the frequent occurrence of hypoglycemia when preexercise glucose concentrations are <120 mg/dl. Moreover, treatment with 15 g of oral glucose is often insufficient to reliably treat hypoglycemia during exercise in these youngsters.
Tansey
Michael J
MJ
DirecNet Coordinating Center, Jaeb Center for Health Research, Tampa, FL 33647, USA. direcnet@jaeb.org
Tsalikian
Eva
E
Beck
Roy W
RW
Mauras
Nelly
N
Buckingham
Bruce A
BA
Weinzimer
Stuart A
SA
Janz
Kathleen F
KF
Kollman
Craig
C
Xing
Dongyuan
D
Ruedy
Katrina J
KJ
Steffes
Michael W
MW
Borland
Timothy M
TM
Singh
Ravinder J
RJ
Tamborlane
William V
WV
D000293:Adolescent; D001786:Blood Glucose / Q000378:metabolism*; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005080:Exercise Test; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D007003:Hypoglycemia / Q000453:epidemiology; D009638:Norepinephrine / Q000097:blood*; D013997:Time Factors
D001786:Blood Glucose; D019382:Human Growth Hormone; D009638:Norepinephrine