Metabolic and physiologic effects of an endotoxin challenge in healthy obese subjects

Clin Physiol Funct Imaging. 2011 Sep;31(5):371-5. doi: 10.1111/j.1475-097X.2011.01026.x. Epub 2011 Apr 7.

Abstract

Aim: The obesity epidemic has increased the number of obese patients admitted to the ICU. In vitro studies suggest that adipose tissue response to inflammation is enhanced: in vivo data are not conclusive yet. The aim of this study was to test the physiologic response of healthy obese subjects to a standardized intravenous LPS challenge.

Methods: Prospective single-blind, randomized, cross-over study in eight subjects (four men, four women), aged 34 ± 7 years, BMI 34·7 ± 4·2, without glucose intolerance and lipid abnormalities, testing the impact of intravenous LPS (2 ng kg(-1) of actual body weight) versus placebo.

Results: Temperature, hemodynamic variables, indirect calorimetry and blood samples (TNF-α, IL-6, stress hormones, hs-CRP) were collected. After LPS temperature, heart rate, TNF-α and Il-6 concentrations and stress hormones (cortisol and glucagon) increased significantly, with maximal responses between 120 and 240 min after the injection. The pattern, the timing and the magnitude of change were similar to those observed in lean subjects.

Conclusion: This study shows that healthy obese subjects have a similar response pattern to intravenous LPS as described in lean subjects.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Biomarkers / blood
  • Blood Pressure
  • Body Mass Index
  • Body Temperature
  • C-Reactive Protein / metabolism
  • Calorimetry, Indirect
  • Cardiac Output
  • Cross-Over Studies
  • Female
  • Glucagon / blood
  • Heart Rate
  • Hemodynamics*
  • Humans
  • Hydrocortisone / blood
  • Inflammation Mediators / blood
  • Injections, Intravenous
  • Interleukin-6 / blood
  • Lipopolysaccharides / administration & dosage*
  • Male
  • Obesity / blood*
  • Obesity / immunology
  • Obesity / physiopathology*
  • Prospective Studies
  • Single-Blind Method
  • Time Factors
  • Tumor Necrosis Factor-alpha / blood

Substances

  • Biomarkers
  • IL6 protein, human
  • Inflammation Mediators
  • Interleukin-6
  • Lipopolysaccharides
  • Tumor Necrosis Factor-alpha
  • C-Reactive Protein
  • Glucagon
  • Hydrocortisone