Sexual Dimorphism in Response to Repetitive Bouts of Acute Exercise in Rodents with Type 1 Diabetes Mellitus
Abstract
The purpose of this study was to examine sex-specific differences in the blood glucose (BG) response to recurrent aerobic exercise in type 1 diabetes. Specifically, we examined the role of peak estrogen (E2) concentrations during proestrus on BG response to prolonged aerobic exercise. To do so, nineteen Sprague-Dawley rats were assigned to four exercised groups: control female (CXF; n = 5), control male (CXM; n = 5), diabetic female (DXF, n = 5) and diabetic male (DXM, n = 4). Diabetes was induced in DX groups via subcutaneous injection of low dose streptozotocin. After four days of exercise, liver glycogen and BG responses were compared. The final bout of exercise took place during proestrus when estrogen concentrations were at their highest in the female rats. No liver glycogen differences between DXF and DXM or CXF and CXM were evident. During days 1-3, DXF had lower BG concentrations during exercise, but quicker BG recovery than DXM. Therefore, fluctuating estrogen concentrations may have reduced the sex based differences in BG response and fuel selection during exercise.