Higher concentrations of osteoprotegerin in type 1 diabetic patients are related to retinopathy: Results from the Poznań prospective study

Abstract

Background. Osteoprotegerin (OPG) is an arterial calcification marker which has been associated with vascular damage. Elevated OPG concentrations associated with low-grade inflammatory processes are found in diabetic subjects. Objectives. The aim of the study was to assess concentrations of OPG in relation to the presence of diabetic complications in patients with diabetes type 1 (DM 1) participating in the Poznań Prospective Study (PoProStu). Material and methods. The study included 74 patients with DM1 (48 men) with a median age of 39 years (interquartile range [IQR]: 34–43) and a median 15-year history (IQR: 14–16) of diabetes, who were participants in the PoProStu. Serum OPG concentration was measured using the ELISA method, and serum concentration of C-reactive protein was measured with a high sensitivity test (hsCRP). The visceral adipose index (VAI) was used to determine indirect markers of insulin resistance (IR). The prevalence of microangiopathic diabetes complications was assessed. Results. Retinopathy was diagnosed in 28 patients (38%), diabetic kidney disease (DKD) in 28 (38%) patients, and neuropathy in 17 (23%) patients. The median OPG level was 43.8 (28.0–74.0) pg/mL. Patients with retinopathy had higher levels of OPG than those without retinopathy: 47.5 (35.0–88.0) vs 35.4 (24.7–69.4) pg/mL (p = 0.04). Positive correlations were observed between OPG concentration and hsCRP (Rs = 0.53; p < 0.001), HbA1c level (Rs = 0.36; p = 0.002), VAI (Rs = 0.23; p = 0.04) and waist circumference (Rs = 0.24; p = 0.04). Conclusions. Higher concentrations of osteoprotegerin in DM1 patients are related to the presence of retinopathy. The study results indicate that OPG might play a role in the pathogenesis of vascular complications in association with hyperglycemia and low-grade inflammatory processes.