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Gut 59:1259-1264 doi:10.1136/gut.2010.214577
  • Hepatology

Anti-inflammatory effects of excessive weight loss: potent suppression of adipose interleukin 6 and tumour necrosis factor α expression

  1. Herbert Tilg1,2
  1. 1Christian Doppler Research Laboratory for Gut Inflammation, Medical University Innsbruck, Austria
  2. 2Department of Internal Medicine II, Medical University Innsbruck, Austria
  3. 3Department of Internal Medicine I, Medical University Innsbruck, Austria
  4. 4Department of Surgery, SJOG (Saint John of God) Hospital, Salzburg, Austria
  1. Correspondence to Prof Herbert Tilg, Christian Doppler Research Laboratory for Gut Inflammation and Department of Internal Medicine II, Medical University Innsbruck, 6020 Innsbruck, Austria; herbert.tilg{at}i-med.ac.at
  • Received 23 March 2010
  • Accepted 16 April 2010
  • Published Online First 21 July 2010

Abstract

Objective Severe obesity is a chronic inflammatory disease where various cytokines/adipocytokines play a key role. Pro-inflammatory cytokines such as interleukin 6 (IL-6) and tumour necrosis factor-α (TNFα) are produced by human adipose tissue dependent on the degree of obesity. Mouse studies suggest a key role of adipose tissue-derived IL-6 in hepatic insulin resistance via modification of liver suppressor of cytokine signalling 3 (SOCS-3) expression.

Design and methods We examined the effect of excessive weight loss on systemic levels, subcutaneous and visceral adipose tissue and liver expression of IL-6 and TNFα in 20 severely obese patients undergoing laparoscopic adjustable gastric banding (LAGB). Furthermore, we studied liver expression of SOCS3, an important regulator of insulin resistance, and fat tissue expression of the anti-inflammatory adipocytokine adiponectin and its receptors. Serum and tissue samples were collected before and 6 months after LAGB surgery.

Results IL-6/TNFα mRNA expression before weight loss were similar in subcutaneous and visceral adipose tissue and much higher compared to hepatic expression. Subcutaneous adipose tissue mRNA expression of both pro-inflammatory cytokines, but especially of IL-6 decreased dramatically after extensive weight loss whereas expression of adiponectin and its receptors increased. Weight loss also led to a significant reduction in liver IL-6 expression, whereas liver TNFα mRNA expression did not change. IL-6 and C-reactive protein serum levels decreased after weight loss whereas TNFα serum levels were below the detection limit before and after surgery. These effects were paralleled by reduced hepatic SOCS3 expression and improved insulin resistance 6 months after LAGB surgery.

Conclusion Expression of IL-6 and TNFα mRNA is more pronounced in adipose compared to liver tissue in patients with severe obesity. Our results highlight excessive weight loss as a successful anti-inflammatory strategy.

Footnotes

  • Competing interests None to declare.

  • Patient consent Obtained.

  • Ethics approval This study was conducted with the approval of the Ethics Committee of Innsbruck Medical University.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Received 23 March 2010
  • Accepted 16 April 2010
  • Published Online First 21 July 2010