Systemic Factors Related to Intraocular Levels of Interleukin-6 and Vascular Endothelial Growth Factor in Diabetic Retinopathy.

Byung Ju Jung,Sohee Jeon,Mee Yon Lee

doi:10.1155/2019/4831967

Abstract

This study is for identifying systemic factors correlating with intraocular levels of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in diabetic retinopathy. Forty-two consecutive patients undergoing pars plana vitrectomy (PPV) for PDR were included in this cross-sectional study. The aqueous humor was sampled just prior to PPV for assay of IL-6 and VEGF. One day before PPV, patient characteristics were recorded and a number of systemic markers were amassed, including fasting and postprandial glucose, homeostasis model assessment- (HOMA-) IR, HOMA-beta, C-peptide, insulin, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein- (Apo-) A, Apo-B, and lipoprotein A (Lp-A). Relationships between systemic determinants and intraocular cytokine levels were analyzed by regression analysis. Mean levels of IL-6 and VEGF were 15.3 pg/mL (range, 2.4–10124.5 pg/mL) and 21.1 pg/mL (range, 3.2–766.1 pg/mL), respectively. After adjustment for age, gender, duration of diabetes, and BMI, multivariate analysis showed significant association of smoking (p=0.002) and HOMA-IR (p=0.003) with intraocular IL-6 levels, while intraocular VEGF and systemic Lp-A levels correlated significantly (p=0.032). Insulin resistance and smoking status impacted intraocular levels of IL-6, while intraocular VEGF levels were influenced by Lp-A. An appreciation for the relationship between systemic factors and intraocular cytokines may help elucidate the complex pathophysiology of diabetic retinopathy.

Highlights

Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes mellitus (DM) and is a leading cause of lost vision in developed countries [1]
A complex process, both inflammatory and angiogenic in nature, is implicated in the development of DR, to include intraocular upregulation of the following cytokines: vascular endothelial growth factor (VEGF) [12, 13], interleukin- (IL-) 1β [14], IL-2 [15], IL-6 [16, 17], IL-8 [18], transforming growth factor- (TGF-) β [19], tumor necrosis factor- (TNF-) α [14], interferon-induced protein- (IP-) 10 [20], and monocyte chemoattractant protein- (MCP-) 1 [21]. rough intricate pathways, these mediators are accountable for the neovascularization and breech of the blood-retinal barrier that occur
IL6, VEGF, insulin, fasting glucose, homeostasis model assessment- (HOMA-)IR, HOMA-beta, total cholesterol (TC), TG, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), Apo-B, and lipoprotein A (Lp-A) values were logtransformed since none displayed normal distribution by the Shapiro–Wilk test

Summary

Research Article

Received 12 March 2019; Revised 18 June 2019; Accepted 5 July 2019; Published 17 July 2019. Is study is for identifying systemic factors correlating with intraocular levels of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in diabetic retinopathy. Forty-two consecutive patients undergoing pars plana vitrectomy (PPV) for PDR were included in this cross-sectional study. One day before PPV, patient characteristics were recorded and a number of systemic markers were amassed, including fasting and postprandial glucose, homeostasis model assessment- (HOMA-) IR, HOMA-beta, C-peptide, insulin, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein- (Apo-) A, Apo-B, and lipoprotein A (Lp-A). Relationships between systemic determinants and intraocular cytokine levels were analyzed by regression analysis. After adjustment for age, gender, duration of diabetes, and BMI, multivariate analysis showed significant association of smoking (p 0.002) and HOMA-IR (p 0.003) with intraocular IL-6 levels, while intraocular VEGF and systemic Lp-A levels correlated significantly (p 0.032). An appreciation for the relationship between systemic factors and intraocular cytokines may help elucidate the complex pathophysiology of diabetic retinopathy

Introduction

Results

Multiple linear regression p value

Regression coefficient p value