Effects of lovastatin therapy on susceptibility of LDL to oxidation during alpha-tocopherol supplementation.
A randomized, double-masked, crossover clinical trial was carried out to evaluate whether lovastatin therapy (60 mg daily) affects the initiation of oxidation of low density lipoprotein (LDL) in cardiac patients on alpha-tocopherol supplementation therapy (450 IU daily). Twenty-eight men with verified coronary heart disease and hypercholesterolemia received alpha-tocopherol with lovastatin or with dummy tablets in random order. The two 6-week, active-treatment periods were preceded by a washout period of at least 8 weeks. The oxidizability of LDL was determined by 2 methods ex vivo. The depletion times for LDL ubiquinol and LDL alpha-tocopherol were determined in timed samples taken during oxidation induced by 2, 2-azobis(2,4-dimethylvaleronitrile). Copper-mediated oxidation of LDL isolated by rapid density-gradient ultracentrifugation was used to measure the lag time to the propagation phase of conjugated-diene formation. alpha-Tocopherol supplementation led to a 1.9-fold concentration of reduced alpha-tocopherol in LDL (P<0.0001) and to a 2.0-fold longer depletion time (P<0.0001) of alpha-tocopherol compared with determinations after the washout period. A 43% prolongation (P<0.0001) was seen in the lag time of conjugated-diene formation. Lovastatin decreased the depletion time of reduced alpha-tocopherol in metal ion-independent oxidation by 44% and shortened the lag time of conjugated-diene formation in metal ion-dependent oxidation by 7%. In conclusion, alpha-tocopherol supplementation significantly increased the antioxidative capacity of LDL when measured ex vivo, which was partially abolished by concomitant lovastatin therapy.
Palomäki
A
A
Department of Internal Medicine, Kanta-Häme Central Hospital, Hämeenlinna, Department of Internal Medicine, Tampere University Hospital, Tampere, Finland.
Malminiemi
K
K
Malminiemi
O
O
Solakivi
T
T
D000328:Adult; D000368:Aged; D003300:Copper / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008148:Lovastatin / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D014810:Vitamin E / Q000494:pharmacology*
D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D014810:Vitamin E; D003300:Copper; D008148:Lovastatin