Effect of differing antecedent hypoglycemia on counterregulatory responses to exercise in type 1 diabetes
Open Access
- 1 June 2006
- journal article
- clinical trial
- Published by American Physiological Society in American Journal of Physiology-Endocrinology and Metabolism
- Vol. 290 (6), E1109-E1117
- https://doi.org/10.1152/ajpendo.00244.2005
Abstract
Hypoglycemia frequently occurs during or after exercise in intensively treated patients with type 1 diabetes mellitus (T1DM), but the underlying mechanisms are not clear. In both diabetic and nondiabetic subjects, moderate hypoglycemia blunts counterregulatory responses to subsequent exercise, but it is unknown whether milder levels of hypoglycemia can exert similar effects in a dose-dependent fashion. This study was designed to test the hypothesis that prior hypoglycemia of differing depths induces acute counterregulatory failure of proportionally greater magnitude during subsequent exercise in T1DM. Twenty-two T1DM patients (11 males/11 females, HbA1c8.0 ± 0.3%) were studied during 90 min of euglycemic cycling exercise after two 2-h periods of previous day euglycemia or hypoglycemia of 3.9, 3.3, or 2.8 mmol/l (HYPO-3.9, HYPO-3.3, HYPO-2.8, respectively). Patients' counterregulatory responses (circulating levels of neuroendocrine hormones, intermediary metabolites, substrate flux, tracer-determined glucose kinetics, and cardiovascular measurements) were assessed during exercise. Identical euglycemia and basal insulin levels were successfully maintained during all exercise studies, regardless of blood glucose levels during the previous day. After day 1 euglycemia, patients displayed normal counterregulatory responses to exercise. Conversely, when identical exercise was performed after day 1 hypoglycemia of increasing depth, a progressively greater blunting of glucagon, catecholamine, cortisol, endogenous glucose production, and lipolytic responses to exercise was observed. This was paralleled by a graduated increase in the amount of exogenous glucose needed to maintain euglycemia during exercise. Our results demonstrate that acute counterregulatory failure during prolonged, moderate-intensity exercise may be induced in a dose-dependent fashion by differing depths of antecedent hypoglycemia starting at only 3.9 mmol/l in patients with T1DM.Keywords
This publication has 38 references indexed in Scilit:
- Effects of Gender on Neuroendocrine and Metabolic Counterregulatory Responses to Exercise in Normal ManJournal of Clinical Endocrinology & Metabolism, 2000
- Prevention of an increase in plasma cortisol during hypoglycemia preserves subsequent counterregulatory responses.JCI Insight, 1997
- The Relationship Between Nonroutine Use of Insulin, Food, and Exercise and the Occurrence of Hypoglycemia in Adults With IDDM and Varying Degrees of Hypoglycemic Awareness and Metabolic ControlThe Diabetes Educator, 1997
- Protection by lactate of cerebral function during hypoglycaemiaThe Lancet, 1994
- Improved Glycemic Control After Supervised 8-wk Exercise Program in Insulin-Dependent Diabetic AdolescentsDiabetes Care, 1987
- Defective Glucose Counterregulation after Strict Glycemic Control of Insulin-Dependent Diabetes MellitusThe New England Journal of Medicine, 1987
- Effects of Exercise Training on Insulin Sensitivity in Adolescents with Type I DiabetesDiabetes Care, 1985
- A Model of the Kinetics of Insulin in ManJCI Insight, 1974
- Lack of Glucagon Response to Hypoglycemia in Diabetes: Evidence for an Intrinsic Pancreatic Alpha Cell DefectScience, 1973
- Preparation of Iodine-131 Labelled Human Growth Hormone of High Specific ActivityNature, 1962