Exercise Improves Glucose Disposal and Insulin Signaling in Pregnant Mice Fed a High Fat Diet.

OBJECTIVE Physical activity has been suggested as a non-pharmacological intervention that can be used to improve glucose homeostasis in women with gestational diabetes mellitus. The purpose of this study was to determine the effects of voluntary exercise on glucose tolerance and body composition in pregnant high fat diet fed mice. METHODS Female mice were put on a standard diet or high fat diet for two weeks. The mice were then split into 4 groups; control standard diet fed, exercise standard diet fed, control high fat diet fed, and exercise high fat diet fed. Exercise mice had voluntary access to a running wheel in their home cage one week prior to mating, during mating, and throughout pregnancy. Glucose tolerance and body composition were measured during pregnancy. Akt levels were quantified in skeletal muscle and adipose tissue isolated from saline or insulin injected pregnant dams as a marker for insulin signaling. RESULTS Consumption of the high fat diet led to significantly increased body weight, fat mass, and impaired glucose tolerance in control mice. However, voluntary running in the high fat diet fed dams significantly reduced weight gain and fat mass and ultimately improved glucose tolerance compared to control high fat diet fed dams. Further, body weight, fat mass, and glucose disposal in exercise high fat diet dams were indistinguishable from control dams fed the standard diet. High fat diet fed exercise dams also had significantly increased insulin stimulated phosphorylated Akt expression in adipose tissue, but not skeletal muscle, compared to control dams on high fat diet. CONCLUSION The use of voluntary exercise improves glucose homeostasis and body composition in pregnant female mice. Thus, future studies could investigate potential long-term health benefits in offspring born to obese exercising dams.