Association Between Serum α-Tocopherol and Serum Androgens and Estrogens in Older Men

Abstract

There is evidence supporting a role for sex hormones in the etiology of prostate cancer. Supplementation with α-tocopherol reduced prostate cancer in the α-Tocoph-erol, β-Carotene Prevention Study (ATBC Study). The objective of this study was to assess the relation of baseline levels of serum α-tocopherol and serum sex hormones in older men. A cross-sectional analysis of serum α-tocopherol and sex hormone concentrations was conducted within a subset of the ATBC Study. Serum was collected in the morning after an overnight fast at baseline from 204 men ages 50-69 years participating in the ATBC Study and free of prostate cancer. Hormones were measured by radioimmunoassay, and α-tocopherol was measured by high-performance liquid chromatography by standard procedures. Multivariate linear regression was used to evaluate the association of serum α-tocopherol with nine androgens and estrogens after controlling for age, body mass index, hormone assay batch, and serum cholesterol. Serum α-tocopherol was significantly inversely associated with serum androstenedione, testosterone, sex hormone-binding globulin, and estrone. The difference in hormone concentration per milligram of α-tocopherol was 1.8-2.6% for these four hormones. These results indicated that α-tocopherol is related to concentrations of several sex hormones in older men and may have implications for the observed protective effect of supplemental vitamin E in relation to prostate cancer in the ATBC Study.