Changes in Serum Fatty Acid Levels During the First Year After Bariatric Surgery

BACKGROUND: We have assessed the effects of laparoscopic sleeve gastrectomy (LSG) and biliopancratic diversion with a duodenal switch (BPDDS) on fatty acid (FA) levels in serum. In particular, we examine the impact of surgery on the ratio of the FAs eicosapentaenoic acid (EPA) to arachidonic acid (AA) which impacts, e.g., cardiovascular health. Our hypothesis is that LSG and BPDDS influence the FA levels but that BPDDS may have a more persistent impact since BPDSS superimposes intestinal malabsorption on gastric restriction. METHODS: Serum samples after overnight fasting were collected 3 months and 1 day before surgery and 3 days, 3 months, and 12 months after surgery from 10 BPDDS patients and 23 LSG patients. The levels of 16 FAs were quantified by gas chromatography. Preoperative and postoperative concentrations of EPA and AA and the ratio of EPA to AA were compared by Wilcoxon signed-rank test corrected for multiple testing using false discovery rate. RESULTS: The ratio of EPA/AA at each of the three postoperative sampling points was lower than at the two preoperative sampling points for BPDDS with p < 0.05 after correcting significance levels for multiple testing. For LSG, the ratio was lower with p < 0.05 at 3 days and at 3 months after surgery, but not after 12 months. CONCLUSION: Both LSG and BPDDS lower the ratio of EPA/AA significantly and below recommended values, but LSG patients resurge toward normal values after approximately 12 months, while BPDDS patients do not.