The relationship between leptin concentrations, the systemic inflammatory response and illness severity in surgical patients admitted to ITU

Background & aims: The relationship between circulation leptin concentrations, mediators of the systemic inflammatory response and illness severity in critically ill patients remains unclear. The aim of the present study was to examine these relationships in critically ill surgical patients admitted to the intensive therapy unit (ITU). Patients and methods: Patients (n=38) who had undergone surgery and subsequently admitted to ITU were prospectively entered into a cross-sectional study. Circulating concentrations of leptin, cortisol, growth hormone, interleukin-6, C-reactive protein and albumin were measured. Sex and age matched controls (n=14) were also studied. Results: On day 1, the critically ill group had lower BMI and leptin concentrations and a pronounced systemic inflammatory response compared with controls. There was a weak positive correlation between leptin concentrations and BMI in the critically ill patients (r=0.42, P<0.10). In contrast, leptin was inversely correlated with C-reactive protein (r=−0.59, P<0.05) but not with cortisol, growth hormone, interleukin-6, APACHE II or predicted mortality. Leptin concentrations did not alter with the day of admission to ITU. Conclusions: On ITU admission, leptin concentrations appeared to be low for BMI, related to the magnitude of the systemic inflammatory response but did not appear to be regulated by proposed mediators in critically ill surgical patients