Interrelationship of elevated serum Advanced Glycation End-product levels and malnutrition (Subjective Global Assessment) scores with the severity of retinopathy in type II diabetes

Abstract

Hyperglycemia in diabetes causes endogenous formation of Advanced Glycation End-products (AGEs) which accumulate in various body parts including retina causing diabetic retinopathy. AGEs also originate from exogenous dietary sources contributing to the body's AGE pool. Currently, curing of diabetic retinopathy is mainly focused on medication, surgical or laser interventions and not much emphasis is given on preventing or halting its occurrence or advancement to more severe stages, nutritionally. Planning a 'low glycemic index-lowAGE' diet therapy for diabetic subjects can reduce endogenous and exogenous origin AGEs in the body and help in controlling retinopathy. Sound and accurate assessment of nutritional status is a crucial step for planning a therapeutic diet for this condition. As this aspect has not gained sufficient attention till now we are assessing the association of serum Advanced Glycation End-product (AGE) levels with the severity of diabetic retinopathy and for the first time estimating the nutritional status of subjects with this eye disorder for long term patient care. This was a tertiary care centre-based, case-control study involving sixty three consecutive cases with diabetes divided as 21 cases with diabetes but no retinopathy, 21 cases with non proliferative diabetic retinopathy (NPDR), 21 cases with proliferative diabetic retinopathy (PDR) along with 21 healthy controls. Serum AGE levels of all the cases and controls were evaluated by Enzyme Linked Immuno Sorbent Assay (ELISA) and nutritional status was assessed by anthropometric measurements and SGA scores. Serum AGE levels were found significantly elevated in PDR group when compared with no retinopathy (p<0.05) and control (p<0.001) group. Control group was also significantly different from (p<0.05) from NPDR group. Increase in SGA scores was statistically significant amongst the four study groups though other indices of nutritional status showed no definite trend with the increasing severity of retinopathy. Our study shows that serum AGE levels are potential risk markers of diabetic retinopathy and SGA can be used as a regular tool for the assessment of nutritional status of diabetic retinopathy subjects which will help planning a 'low glycemic index-low AGE' therapeutic diet for halting this morbidity.