Physical exercise improves insulin sensitivity and thus reduces the risk for type 2 diabetes. However, every fifth person fails to improve after physical excercise intervention. Researchers from the German Center for Diabetes Research (DZD) found out why. They discovered that the signaling molecule TGFß is activated in the muscles of non-responders. TGFß inhibits genes that are involved in the glucose and fat oxidation and reduces insulin sensitivity. The DZD study involved 20 people with a high risk for type 2 diabetes who participated in a two-month long exercise program. They all lost weight and became more fit, yet in eight participants the insulin sensitivity did not improve. It may be that personalized training could help to lower the diabetes risk in these non-responders.
Böhm, A., et al. (2016) TGFβ contributes to impaired exercise response by suppression of mitochondrial key regulators in skeletal muscle. Diabetes, DOI: 10.2337/db15-1723