Increased FNDC5 is associated with insulin resistance in high fat-fed mice.

FNDC5/irisin, has recently been identified as a novel protein that stimulates the "browning" of white adipose by inducing thermogenesis via increased uncoupling protein 1 (UCP1). We tested the hypothesis that high fat diet-induced prediabetic mice would exhibit increased FNDC5 and this effect would be attenuated by chronic exercise. C57BL/6 mice were randomized into three groups for the 4 week intervention: Standard diet (Std, =12), High fat diet (HF, =14), or High fat diet and free access to a running wheel (HFEX, =14).