A new compound-specific pleiotropic effect of statins: modification of plasma gamma-tocopherol levels.

Gamma tocopherol (gamma-T) is a recognized peroxynitrite scavenger, reputedly metabolized via the cytochrome P450 3A4 (CYP3A4). In this study, we assessed whether equipotent LDL-lowering doses of statins with or without inhibitory activity on CYP3A4 differently affect gamma-T metabolism. Patients with ATP III criteria for statin use (n=35) were randomly allocated to treatment with simvastatin 20mg/day or pravastatin 40 mg/day. Plasma lipids, alpha-tocopherol (alpha-T), gamma-T as well as the urinary excretion of the gamma-T metabolite 2,7,8-trimethyl-2-(2'carboxyethyl)-6-hydroxychroman (gamma-CEHC), were determined at baseline and after 6 weeks of treatment. Pravastatin and simvastatin equally reduced LDL-C (-42.8+/-2.9 and -42.1+/-3.0%) and alpha-T levels (-17.5+/-4.2 and -12.2+/-4.1%), and increased the alpha-T/LDL-C ratios (51.4+/-14.6 and 60.4+/-15%). Conversely, pravastatin did not affect whereas simvastatin significantly augmented plasma gamma-T levels (22+/-7.9%, p=0.009, between groups p=0.0045). Moreover, the gamma-T/LDL-C ratio increased significantly more with simvastatin than with pravastatin (124+/-23 versus 61.3+/-22.1%, p=0.05 between groups). In addition, pravastatin but not simvastatin increased the urinary excretion of gamma-CEHC (34.3+/-17.3%, p=0.056; between groups p=0.046). In conclusion, simvastatin and pravastatin produced distinct effects on gamma-T metabolism, presumably as a result of different statin-CYP interactions.

RCT Entities:   Population Interventions Outcomes