Modifications of alpha-tocopherol and fatty acid concentrations in blood and adipose tissue of obese patients during a weight loss programme.

Background and Aim: The aim of the study was To describe qualitative and/or quantitative modifications of lipoproteins, including their fatty acid composition, in obese patients during a hypocaloric diet, and determine whether the variations observed paralleled modifications of alpha-tocopherol concentration in adipose tissue and blood Methods and Results: 15 healthy obese volunteers (5 males, 10 females; age: 32-69 yr; BMI: 28.4-60.5 kg/m(2)) were given a 3-week hypocaloric diet (3.9 MJ (941 kcal)). Adipose tissue and blood samples were taken at the beginning and at the end of this period At baseline and after 3 weeks measurements were made for alpha-tocopherol and fatty acids in total serum, lipoproteins and adipose tissue; thiobarbituric acid-reactive substances (TBARS) in serum. A significant drop in cholesterol-rich particles (LDL and HDL) was observed in parallel to a significant enrichment of n-6 polyunsaturated fatty acids (PUFA) at the expense of both saturated and monounnsaturated fatty acids in serum. A drop in alpha-tocopherol concentration (expressed as mu mol alpha-tocopherol/g lipid) in serum and lipoprotein fractions paralleled the decrease in cholesterol-rich lipoproteins. Conclusions: Our results suggest that a hypocaloric diet not only decreases cholesterol-rich particle levels in serum, but also leads to a significant modification of fatty acid composition which may reflect improvement of insulin sensitivity. We did nor observe any modification in adipose tissue after diet with regard to both alpha-tocopherol and fatty acid concentrations. Despite a drop in alpha-tocopherol concentration and an increase in n-6 PUFA content in serum, we did not Sind any enhancement of serum lipid peroxidation level evaluated by the thiobarbituric acid-reactive substance (TBARS) assay If we assume that dietary intakes of alpha-tocopherol were Mot modified during this diet it can be supposed that adipose tissue released alpha-tocopherol without any specific regulation, in parallel to the release of fatty acids. Nutr Metab Cardiovasc Dis (1999) 9: 25-32 (C) 1999, Medikal Press.