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United States Department of Agriculture

Agricultural Research Service

Research Project: DIETARY MODULATION OF OBESITY-RELATED CANCER BY SELENIUM

Location: Dietary Prevention of Obesity-related Disease Research

Title: Determinants of selenium status in healthy adults)

Author
item Combs, Gerald
item Watts, Jennifer
item Jackson, Matthew
item Johnson, Luann
item Zeng, Huawei
item Scheett, Angela
item Uthus, Eric
item Schomburg, Lutz
item Hoeg, Antonia
item Hoefig, Carolin
item Davis, Cindy
item Milner, John

Submitted to: Nutrition Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2011
Publication Date: 7/18/2011
Publication URL: http://handle.nal.usda.gov/10113/58185
Citation: Combs, G.F., Watts, J.J., Jackson, M.I., Johnson, L.K., Zeng, H., Scheett, A.J., Uthus, E.O., Schomburg, L., Hoeg, A., Hoefig, C.S., Davis, C.D., Milner, J.A. 2011. Determinants of selenium status in healthy adults. Nutrition Journal. 10(75):1-10.

Interpretive Summary: Because levels of selenium (Se) poorly reflect nutritional Se status of non-deficient individuals, including most Americans, a more informative means of characterizing Se status in such individuals is needed. Therefore, we conducted a study to elucidate the relationships among biomarkers of Se status and relevant metabolic and genetic factors in non-deficient individuals. In a cohort of 261 healthy men and women, we measured several biomarkers of Se status, evaluating them in relation to selenoprotein genotypes, dietary Se intake, and parameters of single-carbon metabolism. We found plasma Se level to average 142 ng/ml and Se intake to be about 114 µg/d. Two specific selenoproteins, glutathione peroxidase and selenoprotein P, comprised just over half of plasma Se. Our results showed that genotype, methyl-group status and body mass index (BMI) contributed to variation in Se biomarkers in this Se-adequate cohort. Individual differences in plasma Se concentration were largely due to differences in the non-specific component of plasma Se.

Technical Abstract: Background: Supplemental Se may reduce cancer risk in individuals below a threshold Se status, e.g., a plasma Se concentration of ca.106 ng/ml. A more informative means of characterizing Se status in non-deficient individuals is needed. Objective: Elucidate the relationships among biomarkers of Se status and relevant metabolic and genetic factors in non-deficient individuals. Design: In a cohort of healthy men (n=106) and women (n=155), several biomarkers of Se status (plasma Se, plasma selenoprotein P [SEPP1], plasma glutathione peroxidase activity [GPX3], buccal cell Se, urinary Se) were evaluated in relation to selenoprotein genotypes (GPCX1, GPX3, SEPP1, selenoprotein 15), dietary Se intake, and parameters of single-carbon metabolism. Results: Plasma Se concentration was 142.0±23.5 ng/ml and estimated Se intake was 114.4±47.9 µg/d. Plasma GPX3 and SEPP1 comprised 10% and 34%, respectively, of plasma Se, with 47% present as non-specific components accounting for virtually all of the interindividual variation. Buccal cell Se was associated with age and plasma homocysteine (hCys), but not plasma Se. SEPP1 showed a quadratic relationship with body mass index, peaking at BMI 25-30. Urinary Se was greater in women than men, and was associated with metabolic body weight (kg0.75), plasmas folate, vitamin B12 and hCys (negatively). A GPX1 genotype (679T/T) had lower plasma Se than other allelic variants. Fasting plasma glucose and HbA1C were not associated with plasma Se. Conclusions: Genotype, methyl-group status and BMI contributed to variation in Se biomarkers in this Se-adequate cohort. Individual differences in plasma Se concentration were largely due to differences in the non-specific component of plasma Se.

Last Modified: 8/24/2016
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