Activation Of Certain Target Genes May Help Explain Why Traditional Exercise Regimens Fail To Boost Insulin Sensitivity In Some Patients With Prediabetes.

The study team then analyzed muscle samples taken from all patients immediately before and immediately after the exercise regimen and looked for systematic differences between patients whose insulin sensitivity had increased and those whose insulin sensitivity had remained the same. They found that in “non-responding” patients whose insulin sensitivity remained unchanged, exercise activated a messenger substance called TGFβ and its target genes, which are associated with increases in inflammatory and macrophage markers. No such activation occurred in responding patients. “TGFβ1 as inhibitor of mitochondrial regulators and insulin signaling is validated in human skeletal muscle cells,” the study authors wrote in Diabetes. “Activated TGFβ1 signaling down-regulates the abundance of PGC1α, AMPKα2, mitochondrial transcription factor TFAM, and of mitochondrial enzymes. Thus, the data suggest that increased TGFβ activity in skeletal muscle can attenuate the improvement of mitochondrial fuel oxidation after training and contribute to the failure to increase insulin sensitivity.” The failure of some cohort patients to translate increased exercise into increased insulin sensitivity was not unusual. Regular exercise greatly increases insulin sensitivity in most pre-diabetic patients, but trials typically find that no change in about 20% of all patients. The investigators who conducted the new study did find some changes when they compared pre-exercise and post-exercise muscle samples from patients whose insulin sensitivity did increase. Such patients saw increased activation in genes associated with burning glucose and fat. - See more at: http://www.hcplive.com/medical-news/studying-the-link-between-exercise-and-insulin-sensitivity#sthash.X1gnKRVO.dpuf http://www.hcplive.com/medical-news/studying-the-link-between-exercise-and-insulin-sensitivity#sthash.X1gnKRVO.dpuf