Low serum adropin is associated with coronary atherosclerosis in type 2 diabetic and non-diabetic patients

Background: Diabetes increases the risk and severity of atherosclerosis. Adropin, a metabolic homeostasis-related protein, has been implicated in the maintenance of metabolic homeostasis. We examined the relationship between serum adropin level and angiographic severity of coronary atherosclerosis in diabetic and non-diabetic patients. Methods: A total of 392 patients with suspected coronary artery disease, who underwent coronary angiography, were assigned into the type 2 diabetic and non-diabetic groups and also classified into four groups according to the quartiles of adropin level. Venous serum samples were collected for adropin measurement by enzyme-linked immunosorbent assay and for biochemistry assay. The angiographic severity of coronary atherosclerosis was assessed by Gensini, Friesinger, and SYNTAX scores. Results: Compared with non-diabetic patients, diabetic patients had lower serum adropin level and higher Gensini, Friesinger and SYNTAX scores (all p<0.001). Serum adropin level was inversely correlated with the Gensini, Friesinger and SYNTAX scores (r(s)=-0.389, -0.390 and -0.386, respectively, all p<0.001) among all patients. Low adropin level was an independent predictor of clinically relevant coronary atherosclerosis (SYNTAX score >11), both in diabetic patients [odds ratio (OR) 0.66, 95% confidence interval (CI) 0.53 0.83; p<0.001] and in non-diabetic patients (OR 0.51, 95% CI 0.35-0.74; p<0.001). Conclusions: Serum adropin level was significantly lower in type 2 diabetic patients than in non-diabetic patients and was inversely and independently associated with angiographic severity of coronary atherosclerosis, suggesting that serum adropin serves as a novel predictor of coronary atherosclerosis.