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

Abstract

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 F 2-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 F 2-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 obesityrelated metabolic alterations involved in the mechanism of hepatic steatosis.

F2-isoprostanes as an indicator and risk factor for coronary heart disease

“…AT1 receptor blockers, used to treat hypertension, also significantly reduce IsoP levels in hyperholesterolemic patients [63]. Weight loss in obese subjects also profoundly lowers IsoP levels [64-69]. These results strongly suggest that effective interventions for CHD will either directly or indirectly lower IsoP values, so that measurement of IsoP values should be a highly useful surrogate endpoint in clinical trials.…”

Potential treatment of human nonalcoholic fatty liver disease with long-chain omega-3 polyunsaturated fatty acids

“…In addition, the gastrectomy improved the PUFA profile in erythrocyte membrane PLs, a change that correlated directly with that in liver PLs and approached the corresponding values of the control group. Since it is unlikely that n‐3 PUFA intake was increased following surgery, the decreased n‐6:n‐3 PUFA ratio suggests that both the intake of ALA and the conversion of ALA to n‐3 PUFAs are low in NAFLD and are involved in the mechanism of hepatic steatosis …”

“…2) In a similar study, Elizondo et al . tested the hypothesis that increased oxidative stress and depleted levels of n‐3 PUFAs in hepatic and erythrocyte membrane PLs of obese NAFLD patients are ameliorated upon surgical weight loss.…”

“…In conclusion, the PUFA pattern in erythrocyte membranes in obese NAFLD patients could serve as an objective biomarker of n‐3 PUFA intake and derangement in hepatic lipid metabolism that contributes to steatosis …”

Supplementation With 2:1 Ratio of N-6:n-3 Polyunsaturated Fatty Acid Improves Liver Steatosis and Serum Cytokine Levels in Young Obese Balinese Women: A Randomized Clinical Trial

“…Another study demonstrated that an increased n-6:n-3 PUFA ratio induces steatosis and inflammation, which leads to NAFLD [12]. Nutritional modification, such as increasing the n-3 PUFA proportion in the diet, can reduce the risk of obesity, inflammation, and oxidative stress and prevent the development of LS [13]. Few types of oil, such as canola oil, contain high n-3 PUFA (ALA) concentration.…”