Obesity-associated alterations in the circadian rhythm of the myokine irisin

Background: The new myokine irisin has been proposed to be secreted upon exercise to promote the browning of white adipose tissue, suggesting irisin as a treatment option for obesity and associated diseases. The proposed induction of irisin by activity is still conflicting. Aims: In this study we wanted to asses whether a circadian rhythm, meals, glucose load or different forms of exercise cause changes in irisin serum level. Methods: We measured irisin serum level in 5 different cohorts (children, young adults, lean, obese) which are distinguishable by the kind (ergometer, aqua-training, school sport) and durat…