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


RESULTS
15 healthy, obese volunteers (5 males, 10 females; age: 32-69 yr; BMI: 28.4-60.5 kg/m2) 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 monounsaturated fatty acids in serum. A drop in alpha-tocopherol concentration (expressed as mumol 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 not 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 find 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 not 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.
Bonnefont-Rousselot
D
D
Laboratoire de Biochimie, Hôpital de la Salpêtrière, Paris, France.
Lepage
S
S
Thérond
P
P
Bastard
J P
JP
Hainque
B
B
Turpin
G
G
Legrand
A
A
Delattre
J
J
Bruckert
E
E
D000273:Adipose Tissue / Q000737:chemistry*; D000328:Adult; D000368:Aged; D018752:Diet, Fat-Restricted; D005227:Fatty Acids / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy* / Q000378:metabolism*; D012680:Sensitivity and Specificity; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis / Q000378:metabolism*; D014810:Vitamin E / Q000097:blood / Q000378:metabolism*; D015431:Weight Loss
D005227:Fatty Acids; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E