Changes in oxidative stress and insulin resistance in morbidly obese patients after bariatric surgery

The prevalence of morbid obesity has seen an increase in developed countries over recent years. Bariatric surgery is almost the only effective strategy for treating super morbidly obese patients. The objective of the study was to evaluate the effects of bariatric surgery on the evolution of the main variables related to diabetes and obesity, especially insulin resistance, parameters of oxidative stress, and inflammatory markers in the early stage after surgery.

The study was undertaken in 17 morbidly obese persons who were scheduled for biliopancreatic diversion of Scopinaro. Measurements were made before surgery and 15, 30, 45, and 90 days after surgery.

We found that significant metabolic changes occurred during the first 90 days after bariatric surgery. The most significant decrease in insulin resistance occurred 15 days after the operation. At this point, the lipid profile and inflammatory and oxidative stress parameters had not improved. One month after surgery, insulin resistance had a parallel evolution to weight and the molecules directly associated with hypertrophic adipose tissue.

We suggest that there are two mechanisms that contribute to the improvement in insulin resistance after biliopancreatic diversion: on the one hand, a short-term effect related to gastric bypass, and on the other hand, a long-term effect from decreased fat mass and resulting changes in the release of molecules directly associated with hypertrophic adipose tissue.