Effect of bariatric surgery on systemic and adipose tissue inflammation

Obese patients are predisposed to developing insulin resistance and associated metabolic diseases such as diabetes and cardiovascular disease. The objective of this study was to determine the effect of bariatric surgery on adipose-derived inflammatory cytokines (adipokines), which play a key role in insulin resistance and obesity. We hypothesized that there is a significant increase in serum and tissue anti-inflammatory adiponectin with a decrease in circulating pro-inflammatory TNF-alpha and MCP-1, leading to reduced inflammation post-bariatric surgery. In this study, we investigated the effects of laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic gastric band on serum and tissue levels of adiponectin and serum levels of MCP-1 and TNF-alpha. Samples of serum and adipose tissue were collected at the time of surgery, 2 weeks and 6 months postoperatively. Adipokine levels were assayed by ELISA kits. A significant increase in adiponectin levels 2 weeks after surgery was observed in the subcutaneous adipose tissue in both groups combined. Serum adiponectin in LRYGB patients showed an increasing trend, while MCP-1 showed a decreasing trend post-surgery. There was no difference in TNF-alpha among the groups. The number of patients enrolled did not allow for statistical power to be reached. Our results show significant and rapid increases in subcutaneous adipose adiponectin as early as 2 weeks post-bariatric surgery demonstrating reduced inflammation and possibly reduced insulin resistance. Future studies are warranted in larger cohorts with additional measurements of insulin sensitivity and inflammation.