World Journal of Medical Sciences 10 (4): 368-374, 2014
ISSN 1817-3055
© IDOSI Publications, 2014
DOI: 10.5829/idosi.wjms.2014.10.4.83137
Corresponding Author: Leqaa A. Moemen, Medical Biochemistry Department, Research Institute of Ophthalmology, Egypt.
368
The Relation Between Advanced Glycation End
Products and Cataractogensis in Diabetics
Leqaa A. Moemen, Atef M. Mahmoud, Asmaa M. Mostafa, Fayek Ghaleb,
1 1 2 3
Margret A. Aziz, Mona A. Abdelhamid, Mohamed Y. Farrag and Iman A. Fahmy
1 4 4 4
Medical Biochemistry Department, Research Institute of Ophthalmology, Egypt
1
Chemist Researcher, National Institute of Oceanography and Fisheries, Egypt
2
Clinical Pathology Unit, Research Institute of Ophthalmology, Egypt
3
Ophthalmology Department, Research Institute of Ophthalmology, Egypt
4
Abstract: Background advanced glycation end products (AGEs) play a pivotal role in cataractogenesis.
Production of AGEs takes place throughout the normal aging process but its accumulation is found to be
accelerated in diabetes. Advanced glycation end products formation and cataract progression are extremely
slow processes and are triggered by the presence of free radicals. Oxidative stress along with AGEs may
integrate resulting in acceleration of cataract formation. Methods in the present study 20 patients with diabetic
cataract, 20 patients with senile cataract, as well as 20 healthy "non- diabetic subjects" (Age and sex matched
healthy controls) were selected from outpatient clinic in the Research Institute of Ophthalmology RIO.
Malondialdehyde (MDA) (Oxidative marker), Total antioxidant capacity (TAC), reduced glutathione (GSH),
Superoxide dismutase (SOD) Antioxidant markers and AGEs were estimated in all studied groups. Results there
were significant decreases in TAC, GSH, SOD activities in both the senile and diabetic cataract groups
compared to the control group. There was statistical significant increase in plasma MDA and AGEs levels in
both the senile and diabetic cataract groups compared to the controls. Conclusion this study demonstrated
increased accumulation of AGEs and increased lipid peroxidation products along with impaired antioxidant
status in patients with both diabetic and senile cataract.
Key words: Advanced Glycation End Products (Ages) Senile Cataract Diabetic Cataract Aging
Oxidative Stress Antioxidants
INTRODUCTION Glycation is a non-enzymatic process in which
Cataract is a visual impairment resulting from concentration [5]. Advanced glycation end products
opacification or optical dysfunction of the lens crystallin. (AGEs) play a pivotal role in loss of lens transparency.
It occurs in diabetic patients (osmotic cataract) as well as AGEs production occurs throughout the normal aging
in non- diabetic patients (senile cataract) where age is the process but its accumulation is found to be more rapid in
main predisposing factor [1]. diabetics [6]. Advanced glycation end products formation
Diabetes mellitus is a group of metabolic diseases is accelerated by oxidative stress as reactive oxygen
characterized by hyperglycemia resulting from defects in species enhance cross-linking between carbohydrate
insulin secretion, insulin action, or both [2]. It is estimated moiety and amino group of protein [7].
that by the year 2030, Egypt will have at least 8.6 million Lipid peroxidation of cellular structures, a
adults with diabetes [3]. Long-term hyperglycemia is consequence of increased oxygen free radicals, is thought
involved in the pathogenesis of diabetic microvascular to play an important role in microvascular complications
and macro-vascular complications and cataractogenesis of diabetes mellitus [8]. The toxic effects of the reactive
[4]. oxygen species are neutralized in the lens by antioxidants
glucose covalently binds to a protein in a high glucose