Effect of Hyperglycemia and Advanced Glycation End-products (AGEs) on Wound Healing in Burn Patients

Background: Burn injury is a serious and life-threatening condition. During the early phase of post thermal injury, patients experience hyperglycemia as a result of the catabolic state and hormonal changes. It leads to impaired glucose hemostasis.Methods: MEDLINE and Embase were searched using Diet OR Nutrition OR Carbohydrate combined with Burn patients OR Wound Healing for full length observational articles, published in English. Reference lists of retrieved articles were also searched for other pertinent studies.Results: Hyperglycemic state following burn injury can be detrimental and can lead to adverse outcomes in these patients if not controlled and resolved quickly. Also burn patients with poor glucose control experience a significantly higher incidence of infections and mortality. Due to the uniqueness of burn patients in terms of the weekly operations, daily dressing changes, and the continuous enteral feeding of large caloric loads, maintaining a hyperinsulinemic euglycemic state is difficult. It has been postulated that hyperglycemia can lead to a deleterious effect on wound healing through the formation of advanced glycation end-products (AGEs). These end products are a heterogeneous compounds complex group that are formed when reducing sugar reactions in a nonenzymatic way with amino acids in proteins and other macromolecules happens. This occurs both exogenously (in food) and endogenously (in humans). Animal-derived foods that are high in fat and protein are generally AGE-rich and are prone to further AGE formation during cooking. The AGEs also stimulate the proinflammatory molecules release, such as tumor necrosis factor alpha (TNF-?) and membrane metalloproteinases (MMPs), which limit wound healing. In addition, the AGE RAGE (AGE receptor) interaction in fibroblasts may cause a decrease in collagen deposition, further compromising the normal healing process.Conclusion: Proper glucose control in burns should be achieved through balanced diet with enough carbohydrate ( 5–7 mg/kg/min) and protein ( 1.5–2 g/kg/d). Suboptimal carbohydrate delivery following burn injury can lead to uncontrolled protein catabolism, whereas excess intake can elicit hyperglycemia and increased levels of AGEs in the burn patient which might delay the wound healing process.