Insulin, glucagon, and leptin in critically ill foals

Background: Endocrine dysregulation of hormones of energy metabolism is well documented in critically ill humans, but limited information exists in septic foals. The purpose of this study was to provide information on the hormonal response to energy metabolism in critically ill foals, focusing on insulin, glucagon, and leptin.

Hypothesis: Concentrations of insulin, glucagon, leptin, and triglycerides will be higher, whereas glucose concentration will be lower in septic foals than in healthy and sick nonseptic foals. The magnitude of these differences will be associated with severity of disease and nonsurvival.

Animals: Forty-four septic, 62 sick nonseptic, and 19 healthy foals <7 days of age.

Methods: In this prospective multicenter cross-sectional study, blood samples were collected at admission. Foals with positive blood culture or sepsis score ≥12 were considered septic.

Results: Septic foals had lower glucose and insulin and higher triglyceride and glucagon concentrations than did healthy foals. Glucagon concentrations were not different between septic foals that died (n = 14) or survived (n = 30). Higher insulin and lower leptin concentrations were associated with mortality. Quantitative insulin-sensitivity check index was higher in septic foals.

Conclusions and clinical importance: Energy metabolism and the endocrine response of related hormones in septic foals are characterized by hypoglycemia, hypertriglyceridemia, low insulin concentration, and high glucagon concentration. Leptin and insulin may have prognostic value for nonsurvival in septic foals. The hormonal response related to energy metabolism in critical illness differs between foals and humans.