Obesity and inflammation: lessons from bariatric surgery.

BACKGROUND: Obesity is associated with a series of comorbid conditions that are characterized by an inflammatory state. The purpose of this review is to update knowledge about obesity, adipose tissue, and inflammation.
METHODS: Review of the published literature using search terms of adipose, inflammation, obesity, and insulin resistance in combinations.
RESULTS: Adipose tissue elaborates proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-alpha, with greater secretion from the stromal vascular fraction than from adipocytes and with greater secretion from visceral than subcutaneous adipose tissue sites. This proinflammatory state is associated with insulin resistance and ameliorated by weight loss, with concurrent increase in production of the anti-inflammatory adipokine adiponectin.
CONCLUSION: Although these associations between obesity and inflammation are clearly important, many questions remain unresolved. It is unclear if benefits of weight loss pertain only to those with a proinflammatory profile, who receive a particular type of obesity surgical procedure, or whether these benefits are sustained over a lifetime. The outcomes associated with anti-inflammatory nutrient supplementation, with or without weight loss, in the obese would also increase our understanding.