Ezetimibe reduces α-tocopherol levels in type 2 diabetes.

OBJECTIVE: α-tocopherol has a protective role against free radical-induced damage. The intestinal absorption of α-tocopherol is in part carried out by Nieman-Pick1-like1 protein, which is the target of ezetimibe, a drug used for the treatment of hypercholesterolemia. Ezetimibe is frequently prescribed to patients with type 2 diabetes in combination with statins. Therefore, the aim of the present study was to investigate the impact of ezetimibe treatment on the blood level of α-tocopherol. MATERIALS AND METHODS: Two hundred patients affected by type 2 diabetes, regularly attending the diabetes clinic, were recruited. All patients should not have received vitamin supplements in the six months preceding the study. α-tocopherol was measured by reverse-phase high-performance liquid chromatography with UV detection. Other laboratory parameters were determined by standard laboratory procedures. Patients were analyzed according to ezetimibe treatment. A linear multivariate regression analysis was used to estimate the factors associated with α-tocopherol level. RESULTS: The majority of patients were on ezetimibe/statin treatment. Patients taking ezetimibe showed a significantly lower α-tocopherol level, 29.9±5.7 vs. 32.9±7.0 μmol/L (p=0.006) compared to those not taking the drug. Ezetimibe was significantly and negatively associated with α-tocopherol level in the multivariate analysis (β standardized coefficient = -.217, p = .002). CONCLUSIONS: Treatment with ezetimibe can reduce α-tocopherol plasma levels by inhibiting the Niemann-Pick C1-like protein. Future studies are required to address the clinical implications of this finding.