Investigation of serum irisin levels of patients with new-onset type 2 diabetes mellitus

Irisin is a myokine, which has been recently defined as a hormon, is released into the blood circulation from the skeletal muscle after a proteolytic cleavage of FNDC5, the level of which is regulated by PGC-1α. Irisin increases glucose tolerance and energy expenditure and improves carbohydrate homeostasis. Metformin is a biguanidine class antidiabetic drug. It inhibits liver gluconeogenesis and decreases insulin resistance. Irisin has a role in the regulation of energy metabolism pathways and its level in the blood has been shown to decrease in persons with Type 2 Diabetes(T2DM). Metformin which is a frequently used drug in treatment of T2DM, also affects the energy metabolism. In this study, by regarding this relationship, it is aimed to reveal the effect metformin on serum irisin levels. 20 patients who had applied to the Department of Endocrinologic and Metabolic Diseases and whose Oral Glucose Tolerance Tests (OGTT) had been found to be impaired were included to this investigation. They were recommended to take metformin and to change their life style, such as exercise and diet and their blood were taken after 1 month. Also, a healthy control group (n=20 ) were formed from persons with almost a similar age and sexual distribution as the patient group and the irisin levels of the blood samples taken from these two groups had been measured by ELISA method. Statistical evaluation of the measurements did not show a significant difference (p=0.780) between the irisin levels of the blood samples taken from the patients before and after 1 month recommended treatment. A similar result were found between the control and the treated groups (p=0.170), while a significant increase (p=0.002) were observed for the irisin levels of the control group when compared with the patients group before treatment. In conclusion, the results obtained from this study had not shown clearly if metformin taken together with the life style change by patients with T2DM had changed their blood irisin levels.