FNDC5 and endothelial dysfunction: Thus, a trend to decrease in circulating levels of irisin in HF diabetics when compared to non-HF patients with T2DM seems to be a sign of incapability of endogenous repair system to compensate initial myocardial damage, so it illustrates an occurrence of maladaptive stage in cardiac remodeling directly related to T2DM-induced microvascular inflammation, endothelial dysfunction and skeletal muscle myopathy [31, 32].