A Feasibility Study Exploring the Impact of a Low Advanced Glycation End-product (AGE) Diet on Skin Autofluorescence (SAF) Levels in Kidney Transplant Recipients

Kidney transplantation is the optimal treatment option for end-stage kidney disease. Cardiovascular disease is the leading cause of death in persons with kidney disease, even after receiving a kidney transplant. Advanced glycation end-products (AGEs) are compounds that form naturally in our bodies from the chemical reaction of sugars with proteins. If the concentration of AGEs becomes excessive in our bloodstream, they can cause damage to almost every tissue and organ in our bodies, which eventually may lead to an increased risk of cardiovascular death and ill health. AGEs are also found naturally in foods and the content of AGEs in foods is increased considerably by using cooking methods that require high temperatures, such as frying, roasting and grilling.

Skin autofluorescence (SAF) is a relatively new, non-invasive, validated and easy to perform technique that measures the skin accumulation of AGEs. It has been reported that kidney transplant recipients have significantly lower SAF levels when compared to persons receiving dialysis; however, these are higher than the general population.

Because of the adverse outcomes (e.g. increased risk of death) strongly associated with higher levels of SAF, several options focused on reducing the accumulation of AGEs have been proposed. One of these promising interventions is the reduction of dietary intake of AGEs. It has been suggested that cooking techniques that avoid very high temperatures such as poaching, steaming, stewing and boiling can significantly reduce the AGE content of food when compared to frying, broiling, grilling and roasting. Several studies conducted in healthy overweight and/or obese volunteers, persons with diabetes and in those with chronic kidney disease and performing peritoneal dialysis have reported that reducing dietary AGE intake is associated with a reduction in blood levels of AGEs, suggesting that a low AGE diet may also be associated with a decrease in SAF. Nevertheless, most of the evidence regarding diet modifications to reduce dietary AGE intake is of low quality and therefore further studies are required. Furthermore, this simple dietary intervention has not been previously study in the kidney transplant population. Therefore, if this proposed feasibility study is successful, we will use these findings to identify ways to design future larger research projects to improve the care of persons with a kidney transplant.

This is a feasibility study that will be conducted in two parts:

Part 1: