Short-term exercise reduces glucose uptake in brain of sedentary adults
In sedentary subjects with impaired glucose tolerance, short-term exercise reduces the insulin-stimulated glucose uptake (GU) of the brain in all regions except the occipital cortex, a recent study shows.
The research team randomized 21 sedentary subjects (aged 43 to 55 years; body mass index [BMI], 18.5 to 35 kg/m2) to one of two exercise regimens: moderate intensity continuous training (MICT: n=11; mean age 48 years) or sprint interval training (SIT; n=10; mean age 50 years).
In the whole population, body mass (p=0.032), BMI (p=0.025), whole body fat (p=0.007) and whole-body insulin sensitivity (p=0.007) significantly changed with time. SIT improved aerobic capacity by 5 percent, which reached statistical significance (p=0.03)
In the participants who underwent SIT, global insulin-stimulated GU significantly decreased by 14 percent (p=0.03). Analysis by region showed that GU was also significantly decreased in the cerebellum, superior frontal gyrus, medial frontal gyrus, temporal cortex, thalamus and cingulate gyrus (p<0.05 for all). Only the occipital cortex had unchanged uptake.
In contrast, participants who underwent MICT experienced no significant changes in insulin-stimulated GU either globally or in any of the regions analysed.
On the other hand, fatty acid uptake in the brain, whether globally or in any of the regions, was not significantly changed after any type of exercise training.
“[A]lthough both SIT and MICT enhanced whole-body insulin sensitivity, only SIT decreased the insulin-stimulated brain GU in the sedentary, middle-aged [individuals] with impaired glucose tolerance,” the researchers said.