title: Low-dose steroid alters in vivo endotoxin-induced systemic inflammation but does not influence autonomic dysfunction.
abstract: Severe injury and infection are associated with autonomic dysfunction. Diminished heart rate variability (HRV) is also observed as a component of autonomic dysfunction and is induced by endotoxin administration to healthy subjects. It is established that low-dose glucocorticoid administration diminishes the systemic inflammatory manifestations of endotoxinemia but the influence of this anti-inflammatory intervention on overall autonomic dysfunction and HRV responses to endotoxin is unknown. This study was designed to assess the influence of a low-dose hydrocortisone infusion upon endotoxin-elicited systemic inflammatory responses including phenotypic features, cytokine production, and parameters of HRV. Of 19 subjects studied, nine received a continuous infusion of hydrocortisone (3 microg/kg/min continuously over 6 h) prior to intravenous administration of Escherichia coli endotoxin (2 ng/kg, CC-RE, Lot #2) while 10 healthy subjects received only the endotoxin after a 6-h period of saline control infusion. Serial determinations of vital signs, heart rate variability assessments, and cytokine levels were obtained over the subsequent 24 h. Prior cortisol infusion diminished the peak TNF-alpha (P < 0.01) and IL-6 (P < 0.0001) responses after endotoxin challenge, as compared to saline infusion controls and diminished the peak core temperature response to endotoxin (P < 0.01). In contrast to the influence of cortisol on the above parameters of systemic inflammation, the significant endotoxin-induced decreases in HRV time and frequency domains were not influenced by prior hydrocortisone treatment. Hence, alterations in autonomic dysfunction occur despite hydrocortisone attenuation of other traditional systemic manifestations of endotoxinemia. The maintenance or restoration of autonomic balance is not influenced by glucocorticoid administration.
authors.affiliation: Division of Surgical Sciences, UMDNJ-Robert Wood Johnson Medical School, Now Brunswick, New Jersey 08903, USA.
authors.forename: Sonia M
authors.initials: SM
authors.lastname: Alvarez
authors.forename: Maria
authors.initials: M
authors.lastname: Katsamanis Karavidas
authors.forename: Susette M
authors.initials: SM
authors.lastname: Coyle
authors.forename: Shou-En
authors.initials: SE
authors.lastname: Lu
authors.forename: Marie
authors.initials: M
authors.lastname: Macor
authors.forename: Leo O
authors.initials: LO
authors.lastname: Oikawa
authors.forename: Paul M
authors.initials: PM
authors.lastname: Lehrer
authors.forename: Steve E
authors.initials: SE
authors.lastname: Calvano
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Lowry
mesh_terms: D000293:Adolescent; D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology*; D015415:Biomarkers; D004731:Endotoxins / Q000009:adverse effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006854:Hydrocortisone / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D007249:Inflammation / Q000097:blood / Q000139:chemically induced* / Q000188:drug therapy / Q000503:physiopathology*; D008070:Lipopolysaccharides / Q000009:adverse effects; D008297:Male
chemical_list: D015415:Biomarkers; D004731:Endotoxins; D008070:Lipopolysaccharides; D006854:Hydrocortisone