1. Diabetes mellitus is usually accompanied by hyperactivity of the hypothalamus–pituitary–adrenal (HPA) axis. Diabetic retinopathy is one of the most devastating complications in diabetes although little is known with regards to the HPA activity in type 2 diabetic patients (T2DM) with diabetic retinopathy. The present study was designed to evaluate the HPA axis activity in type 2 diabetic patients with diabetic retinopathy.
2. Diabetic retinopathy was examined by fluorescein fundus angiography (FFA) in 174 consecutive type 2 diabetic patients. Levels of / were measured using flow cytometry. Serum concentrations of interleukin (IL)-1β, IL-6, tumour necrosis factor-α (TNF-α), adrenocorticotrophic hormone (ACTH) and cortisone were measured by radioimmunoassay. Plasma levels of monoamines norepinephrine (NE) and dopamine (DA) were assessed using high performance liquid chromatograph equipped with a fluorescence detection. Patients were grouped into the non-diabetic retinopathy (NDR), non-proliferating diabetic retinopathy (NPR) and proliferating diabetic retinopathy (PDR) categories.
3. Patients with PDR showed significantly less than those with NDR and NPR (P < 0.05). No significant correlation was found in / and NK or severity of retinopathy among the three patient groups. There was no significant difference in serum IL-1β, IL-6 and TNF-α levels among the different patient groups (P > 0.05). The serum concentrations of ACTH and cortisone were lower in PDR patients than other groups. There was no significant difference in plasma concentrations of DA and NE among all three groups (P > 0.05).
4. Our data suggest that HPA and immune dysfunction might play a role in the development and/or progression of PDR.