Effects of weight loss on liver and erythrocyte polyunsaturated fatty acid pattern and oxidative stress status in obese patients with non-alcoholic fatty liver disease.

Our aim was to study the influence of weight loss on the fatty acid (FA) composition of liver and erythrocyte phospholipids and oxidative stress status in obese, non-alcoholic, fatty liver disease (NAFLD) patients. Seven obese NAFLD patients who underwent subtotal gastrectomy with a gastro-jejunal anastomosis in roux and Y were studied immediately and 3 months after surgery. Seven non-obese patients who underwent anti-reflux surgery constituted the control group. Serum F2-isoprostane levels were measured by GS/NICI-MS/MS and FA composition was determined by GC. At the time of surgery, controls and obese patients exhibited a hepatic polyunsaturated fatty acid (PUFA) pattern that correlated with that of erythrocytes. Three months after surgery, NAFLD patients lost 21% of initial body weight; serum F2-isoprostane levels decreased by 76%; total PUFA, long-chain PUFA (LCPUFA), n-3 PUFA, and n-3 LCPUFA increased by 22, 29, 81, and 93%, respectively; n-6/n-3 LCPUFA ratio decreased by 51%; docosahexaenoic acid/docosapentaenoic acid ratio increased by 19-fold; and the n-3 product/precursor ratio (20: 5 + 22: 5 + 22: 6)/18: 3 increased by 164% (p<0.05). It is concluded that weight loss improves the n-3 LCPUFA status of obese patients in association with significant amelioration in the biomarkers of oxidative stress, membrane FA insaturation, and n-3 LCPUFA biosynthesis capacity, thus representing a central therapeutic issue in the improvement of obesity-related metabolic alterations involved in the mechanism of hepatic steatosis.