News from the MyoGlu study

Kåre Inge Birkeland’s group has recently published a new article in Diabetologia with interesting results from the MyoGlu-study. Studies on secreted factors from adipose tissue (“adipokines”) and insulin resistance indicate beneficial effects of life style interventions, but have so far focused on few adipokines mostly related to visceral adipose tissue and weight loss interventions. Long-term physical exercise has profound effects on the subcutaneous white adipose tissue secretome and insulin sensitivity in mice, but such studies on humans are lacking. Lee et al analysed changes in the subcutaneous white adipose tissue (scWAT) secretome using global mRNA sequencing on biopsies, and measured adipokines in blood obtained from dysglycaemic and normoglycaemic men before and after 12 weeks of intensive strength and endurance exercise (https://rdcu.be/bykzP). The key question raised in the article was how long-term physical exercise could influence global expression of secreted factors in scWAT and plasma concentrations of such factors in men with dysglycaemia compared with healthy weight men with normoglycaemia. The main finding was a distinct effect of 12 weeks of exercise on the scWAT secretome specifically for dysglycaemic men, with minimal alterations observed in normoglycaemic men. Several secreted factors related to inflammation were reduced in response to exercise training in dysglycaemic, but not in normoglycaemic men. These inflammation-related factors were elevated in dysglycaemic vs. normoglycaemic men at baseline and correlated negatively with insulin sensitivity. Interestingly, exercise training normalized the differences between dysglycaemic and normoglycaemic men in regards to these inflammatory-factors. Furthermore, alterations in the scWAT secretome were mirrored in plasma adipokine concentrations, as exemplified by SFRP4. These findings indicate that scWAT may be an important mediator of exercise-induced improvements in insulin sensitivity for individuals at risk of developing type 2 diabetes.