Elevated plasma levels of copeptin linked to diabetic retinopathy in type 2 diabetes.

BACKGROUND: The arginine vasopressin (AVP) system has been postulated to play a role in glucose homeostasis, insulin resistance, and diabetes mellitus in human and animal studies. The aim of this study was to evaluate the role of plasma copeptin in Chinese patients with type 2 diabetes mellitus (T2DM) with and without diabetic retinopathy (DR).

METHOD: Plasma copeptin concentrations were determined in 281 patients with T2DM. At baseline, demographic and clinical information including presence of DR and vision-threatening DR (VTDR) was collected. The relationship between copeptin and DR or VTDR was investigated using logistic regression.

RESULTS: T2DM participants with DR or VTDR had significantly higher plasma copeptin concentrations on admission (P < 0.0001). Receiver operating characteristics to predict DR and VDTR demonstrated areas under the curve for copeptin of 0.784 (95% confidence interval [CI] 0.724-0.844) and 0.834 (95% CI 0.781-0.904), respectively, which were superior to those for the homeostasis model assessment of insulin resistance (DR AUC 0.736, 95% CI 0.676-0.797; VTDR AUC 0.754, 95% CI 0.703-0.828; P < 0.01). Multivariate logistic regression analysis adjusted for common DR risk factors showed plasma copeptin concentrations ≥28.6 pmol/L (>3rd quartile) to be an independent marker of DR (OR 3.68, 95% CI 2.04-6.79; P < 0.0001) and VTDR (OR 4.32, 95% CI 2.12-8.14; P < 0.0001).

CONCLUSIONS: We found that increased plasma copeptin concentrations were an independent marker of DR and VDTR in Chinese patients with T2DM, suggesting a possible role of copeptin in the pathogenesis of DR complications.