Acute exercise-induced glucose change during an exercise program in type 2 diabetes

Supervised exercise programs have been demonstrated to improve overall glycemic control but less well characterized is the evolution of glucose response to exercise during an exercise program. We addressed this issue, using an observational cohort design, among overweight adults with type 2 diabetes. We hypothesized that during the course of the program, glucose levels during exercise would become more stable, as insulin sensitivity improved. Among adults with type 2 diabetes, glucose levels often decline acutely during exercise.

Thirty-five adults with type 2 diabetes underwent capillary blood glucose (CBG) testing before and after supervised exercise during a 24-week program (48 sessions). After-exercise CBG values were subtracted from before-exercise values (CBG difference). Through repeated measures analysis, we examined CBG difference, before-exercise values, and after-exercise values during the program. Assuming that some initial period of exercise training is necessary to impact CBG difference, in exploratory analyses, we varied the time period analyzed (eg. Weeks 2-24, Weeks 3-24, etc).

CBG difference appeared stable throughout the program when all available data were considered. In models that examined periods following Week 11, however, the magnitude of CBG difference declined progressively, as did before-exercise values. After-exercise values remained stable for all time periods examined.

Our exploratory analyses suggest that following 11 weeks of exercise supervision, before-exercise CBG values decline progressively but after-exercise values remain stable, resulting in a progressive decline in CBG difference.