Increased levels of irisin in people with long-standing Type1 diabetes

BackgroundIrisin stimulates browning of white adipose tissue and improves metabolic control in mice. Betatrophin, another recently described hormone, improves metabolic control in mice by inducing -cell proliferation. Invitro, irisin stimulates the expression of betatrophin in rat adipocytes. There is a great interest in developing drugs that target or use these hormones for the treatment of obesity and diabetes. We have previously reported on increased levels of betatrophin in people with Type1 diabetes, but the levels of irisin are currently unknown. AimTo characterize the levels of irisin in Type1 diabetes and investigate a potential correlation with betatrophin. MethodsIrisin and betatrophin were measured by enzyme-linked immunosorbant assay (ELISA) in 45 individuals with Type1 diabetes and in 25 healthy controls. ResultsIrisin levels were increased in people with Type1 diabetes, and especially in women. Negative correlations between irisin levels and age at onset of Type1 diabetes and plasma triacylglycerol levels were observed. Interestingly, in women with Type1 diabetes a negative correlation between irisin and insulin doses was also observed. When computing correlations for all study participants, a positive correlation between irisin and total betatrophin was observed, but not between irisin and full-length betatrophin. ConclusionWe report on increased circulating levels of irisin in people with Type1 diabetes, especially in women. For women with Type1 diabetes, the levels of irisin correlated with lower insulin requirements. Further studies are clearly needed to determine the role of irisin in Type1 diabetes.