Alpha-tocopherol supplementation decreases electronegative low-density lipoprotein concentration [LDL(-)] in haemodialysis patients.
BACKGROUND
Oxidative stress is a significant contributor to cardiovascular diseases (CVD) in haemodialysis (HD) patients, predisposing to the generation of oxidized low-density lipoprotein (oxLDL) or electronegatively charged LDL subfraction. Antioxidant therapy such as alpha-tocopherol acts as a scavenger of lipid peroxyl radicals attenuating the oxidative stress, which decreases the formation of oxLDL. The present study was designed to investigate the influence of the alpha-tocopherol supplementation on the concentration of electronegative low-density lipoprotein [LDL(-)], a minimally oxidized LDL, which we have previously described to be high in HD patients.


METHODS
Blood samples were collected before and after 120 days of supplementation by alpha-tocopherol (400 UI/day) in 19 stable HD patients (50 +/- 7.8 years; 9 males). The concentrations of LDL(-) in blood plasma [using an anti-LDL- human monoclonal antibody (mAb)] and the anti-LDL(-) IgG auto-antibodies were determined by ELISA. Calculation of body mass index (BMI) and measurements of waist circumference (WC), triceps skin folds (TSF) and arm muscle area (AMA) were performed.


RESULTS
The plasma alpha-tocopherol levels increased from 7.9 microM (0.32-18.4) to 14.2 microM (1.22-23.8) after the supplementation (P = 0.02). The mean concentration of LDL(-) was reduced from 570.9 microg/mL (225.6-1241.0) to 169.1 microg/mL (63.6-621.1) (P < 0.001). The anti-LDL(-) IgG auto-antibodies did not change significantly after the supplementation. The alpha-tocopherol supplementation also reduced the total cholesterol and LDL-C levels in these patients, from 176 +/- 42.3 mg/dL to 120 +/- 35.7 mg/dL (P < 0.05) and 115.5 +/- 21.4 mg/dL to 98.5 +/- 23.01 mg/dL (P < 0.001), respectively.


CONCLUSIONS
The oral administration of alpha-tocopherol in HD patients resulted in a significant decrease in the LDL(-), total cholesterol and LDL-C levels. This effect may favour a reduction in cardiovascular risk in these patients, but a larger study is required to confirm an effect in this clinical setting.
Mafra
Denise
D
Department of Clinical Nutrition, Federal Fluminense University (UFF), Niterói, Brazil. dmafra@terra.com.br
Santos
Felipe Rizzetto
FR
Lobo
Julie Calixto
JC
de Mattos Grosso
Daniela
D
Barreira
André Luis
AL
Velarde
Luis Guillermo Coca
LG
Abdalla
Dulcinéia Saes Parra
DS
Leite
Maurilo
M
D000284:Administration, Oral; D000328:Adult; D000975:Antioxidants / Q000494:pharmacology*; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002784:Cholesterol / Q000097:blood; D002908:Chronic Disease; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000097:blood* / Q000628:therapy; D008077:Lipoproteins, LDL / Q000097:blood* / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012307:Risk Factors; D024502:alpha-Tocopherol / Q000494:pharmacology*
D000975:Antioxidants; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D002784:Cholesterol; D024502:alpha-Tocopherol