Effect of sub-deficient zinc status on insulin sensitivity after burn injury in rats

Although zinc status is an important parameter in insulin sensitivity, data concerning its implication in noxious burn-induced insulin resistance are scarce. The present study was designed to evaluate the impact of zinc status before burn on the recovery of injury with focus on plasma insulin and glucose levels. The experiment was performed in male adult Wistar rats fed from weaning with a zinc normal diet (80 ppm) or a depleted zinc diet (10 ppm) for 8 weeks and burned to third degree on 20% of their total body surface area. Blood and tissue samples were collected 3, 6, and 24 h after injury in order to study biochemical parameters and the glucose/insulin response in relation with the zinc status. After burn, zinc-depleted rats presented an exacerbated decrease in plasma zinc level. In addition, the burn-induced insulin resistance, leading to protein catabolism, was emphasized, with higher plasma insulin, glucose, and leptin levels in zinc-deficient animals versus normal-fed rats. Our experimental results underlined the interest to early control the zinc status in order to limit the deleterious effects of oxidative stress and insulin resistance in burned patients.