The observation of secretogranin Ⅲ in the peripheral blood and vitreous of patients with diabetic retinopathy

Abstract

Objective: To study the expression levels of secretogranin Ⅲ (SCG3) in the peripheral blood and vitreous of patients with diabetic retinopathy (DR). Methods: Cross-sectional research. A total of 77 patients (41 men and 36 women, 77 eyes) received vitrectomy in Tianjin Medical University Eye Hospital from May to December 2018, with an average age of (60.75±11.34) years. According to the blood glucose level, diabetes history and fundus status, all the patients were divided into the DR group and the non-diabetic group. According to the patients' blood lipids and body mass index (BMI), patients were further divided into subgroups of high blood lipids, normal blood lipids, high BMI and normal BMI. All patients were tested with eye examinations, height and weight to calculate the BMI, and blood lipid levels in the peripheral blood. The vitreous was collected during the vitrectomy surgery, and the levels of SCG3 in the vitreous and peripheral blood were analyzed by ELISA. All the data were analyzed statistically with Wilcoxon rank sum test. Results: There were 43 patients in the DR group, among whom 25 had hyperlipidemia, 18 had normal blood lipids, 22 had a high BMI, and 21 had a normal BMI. There were 34 patients in the non-diabetic group, among whom 13 had hyperlipidemia, 21 had normal blood lipids, 17 had a high BMI, and 17 had a normal BMI. The level of SCG3 in the DR group [6.02 (4.34, 11.76) ng/ml] was higher than that in the non-diabetic group [4.30 (3.20, 10.78) ng/ml] (Z=-2.339, P =0.019). The level of SCG3 in the hyperlipidemia subgroup of the DR patients [7.94 (5.33, 13.51) ng/ml] was higher than that in the normal blood lipid subgroup of the non-diabetic patients [4.04 (3.12, 7.77) ng/ml] (Z=-3.473, P=0.001), and higher than that in the DR patients without hyperlipidemia [4.45 (3.71, 9.14) ng/ml] (Z=-2.511, P=0.012). The level of SCG3 in the DR patients with a high BMI [7.12 (4.56, 13.12) ng/ml] was higher than that in the non-diabetic patients with a normal BMI [3.53 (3.16, 4.38) ng/ml] (Z=-3.767, P =0.000). The level of SCG3 in the DR patients with a normal BMI [5.72 (4.10, 11.60) ng/ml] was higher than that in the non-diabetic patients with a normal BMI (Z=-2.862, P = 0.004). SCG3 in the plasma was rare or can not be detected. Conclusions: The concentration of SCG3 in the vitreous increase in DR patients. However, SCG3 can not be detected in the healthy vascular system. (Chin J Ophthalmol, 2020, 56: 933-937).