Leptin, ghrelin, and adiponectin in the metabolic adjustment to burn injury in children.

Objective. Leptin, adiponectin, and ghrelin have diverse roles in the control of inflammation and metabolism in a normal state as well as in a chronic disease state. The aim of this study was to evaluate their role in the extreme metabolic and proinflammatory state after burn injury and during the initial weeks of recovery. Methods. A prospective descriptive study in a tertiary care center was undertaken. Patients were comprised of 5 children aged 20-108 months with severe burn injury; burn size ranged from 15%-36% of total body surface area. Early enteral feeding, according to estimated energy expenditure, was initiated as 150% of the recommended dietary allowance and in accordance with the patients' nitrogen balance. Seven blood samples were collected sequentially, approximately 5 days apart, during the first 65 days after the burn injury. Samples were tested for leptin, ghrelin, and adiponectin. Results. Leptin, ghrelin, and adiponectin had a similar trajectory of concentration over time: low levels at the beginning, increasing until 2-3 weeks post-burn, where they reached a plateau at 5 weeks post-injury. The typical inverse correlations of ghrelin and adiponectin with leptin were absent. Interleukin-6 was negatively associated with ghrelin and adiponectin and was not associated with leptin. Insulin-like growth factor-1 (IGF-1) had a positive association with the 3 hormones; however, their profiles differ in their relationship to the expected concentration based on a literature review. Ghrelin and adiponectin were higher, leptin and IGF-1 were lower than expected. Conclusions. In the early weeks after burn injury, the hypermetabolic state and inflammation have a major effect on leptin, ghrelin, and adiponectin. The concurrent and similar change of the 3 hormones serves the parallel anabolic and catabolic processes during the recovery from burn injury.