The Effects of Exercise Training on Glucose Homeostasis and Muscle Metabolism in Type 1 Diabetic Female Mice

Abstract

Although exercise training is an important recommendation for the management of type 1 diabetes (T1D), most of the available research studies predominantly focus on male subjects. Given the importance of sex as a biological variable, additional studies are required to improve the knowledge gap regarding sex differences in T1D research. Therefore, the purpose of this study was to examine the role of exercise training in mediating changes in glucose homeostasis and skeletal muscle metabolism in T1D female mice. Female mice were injected with streptozotocin (STZ) to induce T1D. Two weeks after STZ injection, control (CON) and STZ mice were exercise trained on a treadmill for 4 weeks. Aerobic exercise training failed to improve glucose tolerance, prevent the decrease in body weight and adipose tissue mass, or attenuate muscle atrophy in T1D female mice. However, insulin sensitivity was improved in T1D female mice after exercise training. Aerobic exercise training maintained skeletal muscle triglyceride content but did not prevent depletion of skeletal muscle or liver glycogen in T1D mice. Gene expression analysis suggested that T1D resulted in decreased glucose transport, decreased ketone body oxidation, and increased fatty acid metabolism in the skeletal muscle, which was not altered by exercise training. These data demonstrate that 4 weeks of aerobic exercise training of a moderate intensity is insufficient to counteract the negative effects of T1D in female mice, but does lead to an improvement in insulin sensitivity.

Peripheral canalicular branching is decreased in streptozotocin-induced diabetes and correlates with decreased whole-bone ultimate load and perilacunar elastic work

“…Further characterization of the disease state could be accomplished by glucose or insulin tolerance testing. Future studies that examine the effect of loading or exercise on diabetic skeletal fragility and the OLCN should use these additional insulin/glucose tolerance tests to assess the disease state, as exercise increases glucose tolerance 56 and insulin sensitivity 57 in STZ-treated animals. Additionally, this study was limited to the use of male mice.…”

Chronic Stress Exacerbates Hyperglycemia-Induced Affective Symptoms in Male Mice

“…First, we only utilized male mice. Male mice have historically been used to study effects of STZ, in large part due to the difficulty of inducing hyperglycemia in female mice [94][95][96][97][98][99]. Given the higher prevalence of depressive-like behavior in female clinical populations, it is critically important to study female models of hyperglycemia-associated depression.…”

The Effects of Resistance Exercise Training on Skeletal Muscle Metabolism and Insulin Resistance Development in Female Rodents with Type 1 Diabetes

“…Most work investigating IR in T1DM from a mechanistic standpoint has been conducted solely in males (35,(38)(39)(40)52), while very limited work has been conducted in females (53,54). The investigation of females with T1DM is war-ranted as it has been shown that sex differences exist in the metabolic effects of exercise (55,56).…”