Neuroendocrine and metabolic responses to moderate, prolonged exercise differ between male and female patients with type 1 diabetes mellitus. Catecholamine response is lower and lipolytic response is greater in females compared with males during exercise, investigators report.
Despite the reduced catecholamine response in females, no difference is seen in endogenous glucose production. Also, glucagon, cortisol and pancreatic polypeptide responses to exercise were similar between the sexes.
These results suggest that the ratio of glucagon to insulin may be the primary determinant of endogenous glucose production during moderate exercise in patients with type 1 diabetes mellitus, according to investigators.
The investigators, from Vanderbilt University School of Medicine and the Nashville Veteran Affairs Medical Center in Nashville, Tennessee, United States, studied seven women and eight men with type 1 diabetes mellitus. Males and females were matched for age, glycemic control duration of diabetes and exercise fitness. None had autonomic neuropathy.
Patients performed 90 minutes of euglycemic exercise at 50 percent of their maximum rate of oxygen consumption with a constant infusion of regular insulin and a variable dextrose infusion to maintain euglycemia.
Neuroendocrine, metabolic and cardiovascular responses were assessed every 15 minutes and indirect calorimetry was performed in the last 10 minutes of exercise.
In addition to the previously stated results, there were no differences between males and females in plasma glucose or insulin levels at baseline or during exercise, or in exogenous glucose infusion rates during exercise. J Clin Endocrinol Metab 2002; 87(11): 5144-5150