FERRITIN IN THE BLOOD OF PATIENTS WITH TYPE 2 DIABETES AND DIABETIC RETINOPATHY: A MARKER OF INFLAMMATION OR ANEMIA?

Measuring the ferritin content in the blood is the most informative test for detecting iron deficiency and is recommended by the protocols for the diagnosis of anemia. However, ferritin as a marker of acute and chronic inflammation is nonspecifically increased in various inflammatory conditions. Mechanisms reflecting the significant role of chronic low-intensity inflammation in the pathogenesis of type 2 diabetes mellitus (T2DM) are being actively studied. Our aim was to analyze the content of ferritin in the plasma of patients with different stages of diabetic retinopathy (DR) on the background of T2DM in comparison with hemogram indicators and inflammatory markers. Ferritin content in blood plasma was determined by enzyme immunoassay in 106 patients with non-proliferative DR, moderate and progressive proliferative DR. The patients showed an increase in ferritin content relative to the control group and a progressive increase with deepening of the stage of retinopathy. In the group of moderate proliferative DR, the indicator was higher than the control by 23%, and in the group of progressive proliferative DR by 26%. The difference in ferritin content was observed in patients depending on gender. In men, an increase in ferritin content was found by 1.6 times relative to the value in women, in groups of proliferative DR, the indicators differed by 1.1 and 1.3 times. Indicators of the number of erythrocytes and hemoglobin content in the blood of male patients had a tendency to decrease compared to similar indicators of healthy men. In patients with T2DM, the ferritin content was elevated regardless of the underlying anemic state, therefore, it cannot be used as a diagnostic test for iron deficiency. A significant two-way correlation of ferritin and interleukin-10 content was found (r = 0.235). No correlation was found with the index of interleukin-1b and non-neuronal enolase, which characterizes the content of ferritin in the blood of patients with DR on the background of T2DM as a marker of chronic inflammation.