Investigation of serum irisin, adropin and preptin levels in obese and athletes

Obesity is a swiftly spreading health problem around the world and comprises a basis for many kind of disorders. Nowadays, the role of endocrine functions of peripheral tissues in regulation of the energy homeostasis becomes even more important. Irisin, adropin and preptin which are newfound endocrinologic factors, contribute to the regulation of energy homeostasis. Irisin protein, which turns white adipose tissue into brown adipose tissue and causes energy expenditure, is particularly indigenous to muscle. Adropin is a protein encoded by ENHO gene which participates in regulation energy homeostasis and maintaining of insulin response. Preptin, on the other hand is a peptide hormon co-secreted with insulin from the pancreatic β cells. These energy regulatory peptides are considered chief important mediators taking charge in cellular communication that may provide clinical benefit in fighting against obesity. Seventy five male individuals between the ages of 30 and 40 were included n the study, consisting of three groups, obese group (n=25), proffesional athletes group (n=25) and sedentary (control) group (n=25). All blood samples are collected after 8 hours overnight fasting period, and serum was separated by centrifugation. The levels of irisin, adropin and preptin were studied in serum samples by using a commercially available ELISA kit. The level of serum irisin in the obese group was significantly higher than those in proffesional athletes and control groups (p<0.01). Conversely, serum adropin level in the obese group was significantly lower in comparison with the other groups. There was no differences between groups in respect to the levels of preptin. The data presented in the current study imply that serum irisin level of proffesional athletes group following a resting period decreased and become comparable to the serum irisin levels of sedantary group while the irisin levels in obese group elevated due to the increased muscle activity. Also, the presence of low serum adropin level in obese group might possibly be a risk factor for metabolic diseases. In conclusion, in order to take advantage of physiological effects of irisin, a non-sedantary lifestyle is recommended. Keywords: Obesity, exercise, irisin, adropin, preptin