Impact of Endotoxin Challenge in Obese Pigs

Duburcq, Thibault*†‡§; Hubert, Thomas*†‡; Saint-Léger, Pierre‡§; Mangalaboyi, Jacques*‡§; Favory, Raphael‡§; Gmyr, Valery*†‡; Quintane, Laurence*†‡; Tailleux, Anne†‡∥¶; Staels, Bart†‡∥¶; Tournoys, Antoine‡**; Pattou, François*†‡; Jourdain, Mercé*†‡§

doi: 10.1097/SHK.0000000000000158
Basic Science Aspects
Editor's Choice

ABSTRACT: Studies exploring the influence of obesity on septic shock remain limited and controversial. Pigs were chosen as a clinically relevant species, resembling to humans in various functions. We hypothesize obesity may impair porcine acute endotoxic shock. Four groups of five “Yucatan” minipigs were studied: lean and obese control groups, lean lipopolysaccharide (LPS) group receiving Escherichia coli endotoxin (LPS) and obese LPS group receiving the same endotoxin dose. We measured hemodynamic and oxygenation parameters, skin microvascular blood flow at rest and during reactive hyperemia, von Willebrand factor, tumor necrosis factor α, and interleukin 6. All measurements were performed at baseline and at 30, 60, 90, 150, and 300 min. Results were given as median with 25th to 75th interquartile range. Control groups remained stable during the study period. In LPS groups, administration of endotoxin resulted in a typical hypokinetic shock. In obese LPS group at 300 min, we observed a significant impairment of cardiac index (1.2 [1.06–1.45] vs. 1.7 [1.57–1.97] L/min per m2, P = 0.008) compared with the lean LPS group; moreover, pulmonary hypertension (mean arterial pressure: 42 [39–47] vs. 32 [28–34] mmHg, P = 0.008), hypoxemia (partial pressure of oxygen: 216 [178–262] vs. 325 [285–414] mmHg, P = 0.02), and lactate levels (5.8 [4.2–6.8] vs. 3.9 [2.2–5.5] mmol/L, P = 0.04) were significantly higher compared with the lean LPS group. Throughout the study, rest flow and peak flow during reactive hyperemia were more decreased in the obese LPS group. Compared with the lean LPS group, tumor necrosis factor α levels at 60 min (269 [178–428] vs. 126 [105–166] ng/mL, P = 0.03) and interleukin 6 levels at 300 min (101 [61–142] vs. 52 [36–64] ng/mL, P = 0.03) were significantly higher in the obese LPS group. In our model of endotoxic shock, obese pigs developed a more severe hemodynamic failure with pronounced microcirculatory dysfunction and proinflammatory response.

*Inserm U859; European Genomic Institute for Diabetes (EGID), FR 3508; Univ Lille 2; §Pole de Réanimation CHRU; Inserm UMR 1011; IPL; and **Centre de Biologie Pathologie CHRU, F-59000 Lille, France

Received 9 Dec 2013; first review completed 1 Jan 2014; accepted in final form 17 Feb 2014

Address reprint requests to Mercé Jourdain, MD, PhD, INSERM U859, Faculté de Médecine de Lille-3ème est, 1, Place de Verdun, 59045 Lille Cedex, France. E-mail: mercedes.jourdain@univ-lille2.fr.

All authors report no funding for support of this work.

The authors declare that they have no competing interests.

© 2014 by the Shock Society