This Award allows Dr. Stapleton to become an independent investigator performing translational research on nutrition and pharmaconutrients in critically ill patients with sepsis, a syndrome that is common in critical illness and has an enormous public health impact. Dr. Stapleton is trained in epidemiology, but to establish herself as an expert leader in nutrition and pharmaconutrient therapy in critical illness, she is seeking additional training in pharmacokinetics and translational research. Through a cohesive program of formal coursework, direct mentoring by outstanding experts, and practical experience conducting her proposed projects, this Award will help her achieve her career goals of translating novel nutrient interventions into clinical application. The overall objective of this proposal is to investigate the pharmacologic behavior and to perform a phase I dose-finding study of zinc in patients with severe sepsis. The biologic rationale for zinc in sepsis is strong. Zinc deficiency is present in nearly all critically ill patients and is associated with increased mortality and organ failure. Zinc supplementation in healthy volunteers restores normal immune function including normalizing lymphocyte count, decreasing inflammatory cytokine production, restoring phagocytic activity of neutrophils, and reducing incidence of infections. Supplementation also decreases organ failure and death in murine sepsis, and there is evidence from a few small clinical trials of antioxidant cocktails including zinc in critically ill humans that supplementation may improve survival.
Aim 1 is a phase I dose-finding study of intravenous zinc in patients with severe sepsis to identify a dose for use in future trials. The endpoints are normalization of plasma zinc level and safety and tolerability parameters including vomiting and diarrhea. The results of this study will lead to R01 or U01 applications for future clinical trials.
Aim 2 defines the pharmacokinetics of zinc in patients with severe sepsis compared to healthy controls and determines a dosing interval for zinc by investigating the hypothesis that the half-life of zinc in severe sepsis patients is significantly lower than in healthy controls.
Aim 3 investigates the impact of zinc on inflammation, immunity, and oxidant defense in patients with severe sepsis through selected laboratory measurements, work which will provide insight into biologic markers for use in future clinical trials. With the rich resources in translational research provided by the Vermont Lung Center, this is an exceptional opportunity for Dr. Stapleton to gain outstanding experience in pharmacokinetics, dose-finding studies, and translational research in critically ill patients with sepsis.
Sepsis is a common syndrome in critical illness, has a tremendous public health impact, and new therapies are urgently needed. Zinc is a novel potential therapy, and this research is an innovative approach that establishes a new paradigm of investigating nutrient delivery to critically ill patients. It rigorously progresses through defining the pharmacokinetics and conducting a phase I dose-finding study, while investigating zinc's biologic impact using obtained blood samples, to obtain information that will inform the conduct of future clinical trials.
