Physiology and role of irisin in glucose homeostasis

Irisin is secreted primarily by muscle and in small amounts by adipose tissueIrisin improves glucose homeostasis, lipid profile and metabolic parameters in animals and acts on adipose tissue by inducing 'browning', as well as on muscle and liverInconsistencies in published data regarding the circulating levels of irisin highlight the need for accurate methods for irisin measurement and for improved study designLevels of irisin are increased in states of obesity and decreased in patients with type 2 diabetes mellitus (T2DM)Future studies should try to identify the irisin receptor and to investigate the effects of irisin on the endocrine pancreas and appetite centres in the brain; prospective clinical studies should investigate whether irisin is a predictive marker for insulin resistance, T2DM or the metabolic syndrome