Review
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Jul 15, 2017; 8(7): 317-329
Published online Jul 15, 2017. doi: 10.4239/wjd.v8.i7.317
Obesity, metabolic syndrome and diabetic retinopathy: Beyond hyperglycemia
Osinakachukwu Mbata, Nada Fawzy Abo El-Magd, Azza Bahram El-Remessy
Osinakachukwu Mbata, Azza Bahram El-Remessy, Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA 30912, United States
Osinakachukwu Mbata, Azza Bahram El-Remessy, Medical College of Georgia/University of Georgia Medical Partnership, 30606 Athens, Greece
Nada Fawzy Abo El-Magd, Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
Azza Bahram El-Remessy, Augusta Biomedical Research Corporation, Charlie Norwood VA Medical Center, Research Service Line, Augusta, GA 30912, United States
Author contributions: Mbata O, Abo El-Magd NF, El-Remessy AB drafted and edited the manuscript; all authors approved final version of the manuscript.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Azza Bahram El-Remessy, PhD, RPh, FAHA, Augusta Biomedical Research Corporation, Charlie Norwood VA Medical Center, Research Service Line, Downtown 6B-105, Augusta, GA 30912, United States. azza.el-remessy@va.gov
Telephone: +1-706-7330188 Fax: +1-706-8232268
Received: November 9, 2016
Peer-review started: November 10, 2016
First decision: February 17, 2017
Revised: March 22, 2017
Accepted: June 6, 2017
Article in press: June 8, 2017
Published online: July 15, 2017
Processing time: 235 Days and 14.5 Hours
Abstract

Diabetic retinopathy (DR) is the most feared ocular manifestation of diabetes. DR is characterized by progressive retinal damage that may eventually result in blindness. Clinically, this blindness is caused by progressive damage to the retinal microvasculature, which leads to ischemia, retinal swelling, and neovascularization. Retinopathy is associated with both type 1 and type 2 diabetes, with DR being the leading cause of new onset blindness in United States adults. Despite this strong association with diabetes, it must be noted that the development of retinopathy lesions is multifactorial and may occur in individuals without an established history of diabetes. Metabolic syndrome is a multifactorial condition of central obesity, hypertriglyceridemia, dyslipidemia, hypertension, fasting hyperglycemia, and insulin resistance. Although several studies examined the individual components observed in the metabolic syndrome in relation to the development of DR, there is conflicting data as to the association of the metabolic syndrome with the development of retinopathy lesions in non-diabetic subjects. This review will summarize the current literature on the evidence of the metabolic syndrome on retinopathy in subjects with and without an established history of diabetes. This review will also discuss some of the mechanisms through which metabolic syndrome can contribute to the development of retinopathy.

Keywords: Diabetic retinopathy; Diabetes; Metabolic syndrome; Oxidative stress; Inflammation; Insulin resistance

Core tip: Metabolic syndrome is a multifactorial condition of central obesity, hypertriglyceridemia, dyslipidemia, hypertension, and fasting hyperglycemia and insulin resistance. Although several studies examined the individual components of the metabolic syndrome in relation to development of diabetic retinopathy, there is conflicting data as to the association of the metabolic syndrome with the development of retinopathy lesions in non-diabetic subjects. This review examined the current literature on the prevalence and impact of the components of the metabolic syndrome on the development of retinopathy in subjects with and without an established history of diabetes.