Adiponectin may play a part in the pathogenesis of diabetic retinopathy

Objectives: To measure plasma adiponectin concentrations in patients with type 2 diabetes and to investigate any association with the severity of diabetic retinopathy, because adiponectin seems to be an important modulator for metabolic and vascular diseases. Methods: Seventy-four patients (mean age 46.8 +/- 5.1 years; body mass index (BMI), 26.8 +/- 2.10 kg/m(2)) and 54 healthy volunteers (mean age 46.8 +/- 5.4 years; BMI 26.47 +/- 2.33 kg/m(2)) were included. Results: Adiponectin concentrations in the patients were significantly lower than those in controls (4.71 +/- 2.11 mug/ml for patients, n = 74; 15.95 +/- 3.72 mug/ml for controls, n = 54; P < 0.001.). In the patients group there was a significant negative correlation between adiponectin and homeostasis model assessment index (r = -0.318, P = 0.006 respectively). Plasma adiponectin concentrations in patients with proliferative diabetic retinopathy (n = 20; 3.16 +/- 1.83 mug/ml) or non-proliferative diabetic retinopathy (n = 24; 3.97 +/- 1.47 mug/ml, P = 0.014) were significantly lower than those in patients without diabetic retinopathy (n = 30; 6.30 +/- 1.57 mug/ml, P = 0.001). When the presence of diabetes was defined as the final variable in the conditional logistic regression model with the adiponectin concentration as the continuous variable, adiponectin was significantly involved in the model. Conclusion: The results show that adiponectin concentrations are lower in patients with type 2 diabetes and that the concentrations are associated with the severity of diabetic retinopathy. Our findings suggest that adiponectin may take part in the pathogenesis of diabetic retinopathy.