Association of lower serum irisin levels with diabetes mellitus: Irrespective of coronary collateral circulation, and syntax score

Irisin is a myokine thought to be involved in the pathophysiological process of atherosclerosis with its' cardiovascular protective effects. Patients with diabetes mellitus (DM) have lower levels of irisin. Therefore, we investigated whether there is a connection between irisin, DM, coronary collateral circulation (CCC), and SYNTAX scores representing coronary artery disease (CAD) severity. This study evaluated 86 patients who have at least one epicardial coronary artery with chronic total occlusion. We included Rentrop 0-1 into the poor CCC group (n=45) and Rentrop 2-3 into the good CCC group (n=41) and measured serum irisin levels. Irisin levels did not differ (17585 [882-37741] pg/ml and (17504 [813-47683] pg/ml, p=0.772) between the two groups. Irisin levels were lower in patients with diabetes (n=41; 14485 [813-29398] pg/ml) than those without diabetes (n=45; 19724 [865-47683] pg/ml (p=0.002). Irisin was not correlated with SYNTAX scores. In multivariate analysis, DM (OR=0.463; CI: 0.184-0.783; p=0.012) was a negative predictor of good CCC development. Although its level is decreased in patients with diabetes, serum irisin levels have no role in the pathophysiology of collateral development and CAD severity.