Hypoglycemia during moderate intensity exercise reduces counterregulatory responses to subsequent hypoglycemia.
Hypoglycemia, which occurs commonly during and following exercise in people with diabetes, is thought to be due to attenuated counterregulation in the setting of therapeutic insulin excess. To better understand the pathophysiology of counterregulation, we aimed to determine if dextrose administration to maintain euglycemia during moderate intensity exercise alters the attenuation of counterregulatory responses to subsequent hypoglycemia in healthy adults : Counterregulatory responses to hypoglycemia were assessed in 18 healthy adults after bed rest and following exercise with (n = 9) and without (n = 9) dextrose infusion. Responses were measured during a stepped euglycemic-hypoglycemic clamp 24 h after either bed rest or two 90-min bouts of exercise at 70% peak oxygen uptake : Hypoglycemia occurred during the second bout of exercise without dextrose infusion. Plasma glucagon and epinephrine responses to stepped hypoglycemia after antecedent exercise without dextrose infusion were significantly lower at the 45 mg/dL glycemic level compared to after bed rest. However, no attenuation of the counterregulatory responses to hypoglycemia was evident after antecedent exercise when dextrose was infused. This study suggests that the attenuation of the counterregulatory responses during hypoglycemia after exercise is likely due to the hypoglycemia that occurs during moderate prolonged exercise and not solely due to exercise or its intensity.
Program in Physical Therapy, Washington University School of Medicine, Saint Louis, Missouri.
W Todd
WT
Cade
Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri.
Nadia
N
Khoury
Division of Biostatistics, Washington University School of Medicine, Saint Louis, Missouri.
Suzanne
S
Nelson
Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri.
Angela
A
Shackleford
Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri.
Katherine
K
Semenkovich
Division of Biostatistics, Washington University School of Medicine, Saint Louis, Missouri.
Melissa J
MJ
Krauss
Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri arbelaez_a@kids.wustl.edu.
Ana María
AM
Arbeláez
D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D004837:Epinephrine / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D005934:Glucagon / Q000097:blood; D005947:Glucose / Q000008:administration & dosage* / Q000627:therapeutic use; D015309:Glucose Clamp Technique / Q000379:methods; D006801:Humans; D007003:Hypoglycemia / Q000097:blood* / Q000209:etiology; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood; D008297:Male
D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon; D005947:Glucose; D004837:Epinephrine
Counterregulatory responses; exercise; hypoglycemia