Omega-3 Fatty Acids in Bariatric Gastric Bypass Surgery: Effect on Liver Volume, Immune Response and Erythrocyte Function

Gastric bypass surgery is the gold standard in bariatric surgery and is a successful method to reduce weight in morbidly obese subjects. Patients qualified for gastric bypass surgery are routinely pre-treated with a low calorie diet in order to reduce liver volume and to facilitate the approach of the gastro-oesophageal junction. Pre-treatment with omega-3 fatty acids has similar effects on liver volume, but a prospective comparison of both treatments has not been performed yet. Morbidly obese patients respond differently to surgical stress, due to a number of factors. First, obesity is associated with a low-grade inflammatory state induced by an increased amount of macrophages in adipose tissue. This state is associated with higher levels of pro-inflammatory cytokines in serum and with a less adequate immune response to infections. Second, obesity is associated with an altered cortisol metabolism possibly related to adrenal insufficiency. This could play an important role in the altered response to surgical stress and postoperative complications in obese subjects. Third, obesity is associated with altered erythrocyte function, including decreased erythrocyte deformability and increased aggregation, factors contributing to an impaired microcirculation.

This study has a number of different aims. First, we will compare pre-treatment with the standard low calorie diet with omega-3 fatty acids on liver volume in patients qualified for gastric bypass surgery because of morbid obesity. Second, we will investigate the effect of omega-3 fatty acids on immune function, the low-inflammatory state of adipose tissue, the stress response of obese subjects before and erythrocyte function. Third, we will investigate the effect of gastric bypass surgery by comparing values before surgery with values on the first postoperative day and 6 months after surgery regarding to immunological parameters, stress response and erythrocyte function.