Endocrine Abstracts

Aims: Irisin is a recently discovered myokine that has been implicated in the pathogenesis of type 2 diabetes (T2D) and metabolic syndrome (MS). Its involvement with cardiovascular disease (CVD), however, has not yet been elucidated. The aim of the current study was to shed light on the potential association with irisin and cardiovascular risk.

Methods: Eighty patients with obesity (BMI ≥ 30 kg/m²) and mean age 50,4±10,6 years were included in the study which was realized in a third level university endocrine department. Biochemical measurements consisted of fasting plasma glucose, serum immunoreactive insulin, serum uric acid, lipid profiles, liver enzymes. Measurements of weight, height, waist circumference and arterial blood pressure were performed. Cardiovascular risk was estimated by means of Framingham Risk Score calculation and a measurement of mean carotid intima media thickness (CIMT) as measured by an automated software via B-mode ultrasound. Ankle-brachial index (ABI) measurement was also performed. Circulating serum irisin was measured by a commercially available ELISA kit.

Results: Among parameters of interest, circulating irisin correlated positively with BMI (r=0, 246, P<0,05) and negatively with age (r=−0,457, P<0,001), total cholesterol (r=−0,246, P<0,05), LDL-cholesterol (r=−0,234, P<0,05), ABI (r=−0,272, P<0,05). CIMT (r=−0,353, P<0,01) and with Framingham Risk Score (r=−0,400, P<0,01). Associations with CIMT, Framingham Risk Score and ABI persisted after adjustment for age and sex. In a ROC-curve analysis circulating serum irisin was of use (AUC=0,665, 95%CI: 0,525-0,804, P=0,037) for distinguishing subjects with CIMT ≥ 75^th percentile, which was found in 32,5% of the study participants

Conclusions: Circulating irisin levels were negatively associated with established CVD estimates. Irisinaemia could be useful for distinguishing subjects with increased CIMT. Larger, prospective studies are required to establish the particular mechanisms for these observations.