In humans, excess accumulation of intramuscular fat has been associated with conditions such as insulin resistance and type 2 diabetes.
Studies demonstrating the effects of IMTGs show that the mechanism involves the activation of the protein kinase C theta, which promotes the phosphorylation of IRS-1, thereby inhibiting the insulin signaling cascade.
However, athletes often do not exhibit this correlation since they are typically insulin sensitive, while expressing high levels of IMTG.
Researchers believe that the improved efficiency of trained skeletal muscles prevents the development of insulin resistance.
In contrast, the build-up of IMTG in obese individuals correlates to high levels of adipose tissue.