The role of adipose tissue and excess of fatty acids in the induction of insulin resistance in skeletal muscle.

Skeletal muscle is the main tissue responsible for insulin-stimulated glucose uptake. Consumption of a high-fat diet rich in saturated fats (HFD) and obesity are associated with accumulation of intramuscular lipids that leads to several disorders, e.g. insulin resistance (IRes) and type 2 diabetes (T2D). The mechanism underlying the induction of IRes is still unknown. It was speculated that accumulation of intramuscular triacylglycerols (TAG) is linked to induction of IRes. Now, research focuses on bioactive lipids: long-chain acyl-CoA (LCACoA), diacylglycerols (DAG) and ceramides (Cer). It has been demonstrated that accumulation of each of the above-mentioned lipid classes negatively affects the insulin signaling pathway. It is not clear which of those lipids play the most important role in HFD-induced skeletal muscle IRes. The aim of the present work is to present the current knowledge of the role of adipose tissue and excess of fatty acids in the induction of insulin resistance.