Effect of Circulating Omentin-1 on the Retinal Circulation in Patients With Type 2 Diabetes Mellitus

Purpose: To identify any significant correlations between retinal circulatory parameters and serum concentrations of omentin-1, a novel adipokine produced by adipocytes, in patients suffering from type 2 diabetes mellitus. Methods: Eighty-seven patients suffering from type 2 diabetes and incipient diabetic retinopathy (DR) were analyzed and further divided into two groups according to sex. We compared the patients' retinal circulatory parameters measured with laser Doppler velocimetry and serum omentin-1 concentrations. Results: The plasma omentin-1 concentrations were related positively to the retinal blood flow (RBF) (r = 0.212; P = 0.048) and primarily with female sex (r = 0.288; P = 0.06) and negatively to the retinal arterial vascular resistance (RVR) (r = -0.218; P = 0.043). Moreover, the plasma omentin-1 concentration was modestly but not significantly positively related to the blood velocity. Multiple regression analysis showed that the serum omentin-1 level contributed independently and negatively to the RVR. Conclusions: Increased concentrations of plasma omentin-1 might be linked to elevated RBF levels probably through elevated blood velocity in patients suffering from type 2 diabetes with incipient DR, especially in female patients, which warrants further investigation.