Optimization of Selenoprotein P in Chinese Subjects

Study Description

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Brief Summary:

The purpose of this study is to determine the amount of selenium as selenomethionine that is required to optimize selenoprotein P in selenium-deficient Chinese subjects

Condition or disease	Intervention/treatment	Phase
Selenium Deficiency	Dietary Supplement: 20 µg selenium; Dietary Supplement: 40 µg selenium; Dietary Supplement: 60 µg selenium; Dietary Supplement: 80 µg selenium; Dietary Supplement: 100 µg selenium; Dietary Supplement: 120 µg selenium; Dietary Supplement: placebo	Not Applicable

Detailed Description:

Selenium is an essential nutrient. The Recommended Dietary Allowance (RDA) for selenium is considered to be the amount required to optimize plasma selenoproteins. There are two selenoproteins present in the plasma: selenoprotein P (Se-P) and glutathione peroxidase 3 (GPX-3). Although the amount of selenium required to optimize GPX-3 has been determined, the amount required to optimize Se-P in the plasma remains unknown. We aim to determine this amount by supplementing selenium deficient subjects with varying amounts of selenium as selenomethionine.

The study will take place in Mianning County, China, where selenium status is low. Approximately 150 people will be screened for eligibility to participate in this study. 98 subjects will be enrolled. Background information obtained from each participant will be: age, height, weight and smoking status.

Subjects will be randomized to a selenium supplement group. The selenium supplement will contain either 0, 20, 40, 60, 80, 100, or 120 µg of selenium as selenomethionine. A CDC worker will visit each participant daily to give them their selenium supplement. The CDC worker will watch them take their supplement and will ask if they have any unanticipated problems. Blood samples of 20 ml will be obtained at weeks 0, 4, 8, 12, 16, 20, 24, 32, and 40. Hair samples and 24-hr urine collections will be obtained at 0, 20 and 40 weeks. The total study duration is 40 weeks.

Study Design

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Study Type :	Interventional (Clinical Trial)
Actual Enrollment :	98 participants
Allocation:	Randomized
Intervention Model:	Parallel Assignment
Masking:	Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose:	Prevention
Official Title:	Optimization of Selenoprotein P in Chinese Subjects
Study Start Date :	March 2007
Actual Primary Completion Date :	December 2007
Actual Study Completion Date :	October 2008

Arms and Interventions

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Arm	Intervention/treatment
Experimental: 1; 20 µg selenium as selenomethionine	Dietary Supplement: 20 µg selenium; 20 µg selenium as selenomethionine
Experimental: 2; 40 µg selenium as selenomethionine	Dietary Supplement: 40 µg selenium; 40 µg selenium as selenomethionine
Experimental: 3; 60 µg selenium as selenomethionine	Dietary Supplement: 60 µg selenium; 60 µg selenium as selenomethionine
Experimental: 4; 80 µg selenium as selenomethionine	Dietary Supplement: 80 µg selenium; 80 µg selenium as selenomethionine
Experimental: 5; 100 µg selenium as selenomethionine	Dietary Supplement: 100 µg selenium; 100 µg selenium as selenomethionine
Experimental: 6; 120 µg selenium as selenomethionine	Dietary Supplement: 120 µg selenium; 120 µg selenium as selenomethionine
Placebo Comparator: 7; placebo	Dietary Supplement: placebo; placebo

Outcome Measures

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Primary Outcome Measures :

1. Plasma selenoprotein P levels at 0, 4, 8, 12, 16, 20, 24, 32, and 40 weeks [ Time Frame: 40 weeks ]

Secondary Outcome Measures :

1. Total plasma selenium concentrations at 0, 4, 8, 12, 16, 20, 24, 32, and 40 weeks [ Time Frame: 40 weeks ]
2. Plasma glutathione peroxidase activity at 0, 4, 8, 12, 16, 20, 24, 32, and 40 weeks [ Time Frame: 40 weeks ]
3. 24hr urinary selenium excretion at 0, 20 and 40 weeks [ Time Frame: 40 weeks ]
4. Hair selenium levels at 0, 20 and 40 weeks [ Time Frame: 40 weeks ]

Eligibility Criteria

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Ages Eligible for Study:	17 Years and older (Child, Adult, Senior)
Sexes Eligible for Study:	All
Accepts Healthy Volunteers:	Yes

Criteria

Inclusion Criteria:

• aged 17 years or older
• healthy
• resident of Mianning County for at least 1 year
• hematocrit (PCV) of 30 or greater

Exclusion Criteria:

• subject has taken selenium supplements within the year prior to study
• subject plans to relocate during study

Contacts and Locations

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Locations

China, Sichuan
Sichuan Center for Disease Control and Prevention (Sichuan CDC)
Chengdu, Sichuan, China

Sponsors and Collaborators

Vanderbilt University

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Investigators

Principal Investigator:	Raymond F Burk, M.D.	Vanderbilt University
Study Director:	Yiming Xia, Ph.D.	Sichuan CDC, Chengdu

More Information

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Publications:

Xia Y, Hill KE, Byrne DW, Xu J, Burk RF. Effectiveness of selenium supplements in a low-selenium area of China. Am J Clin Nutr. 2005 Apr;81(4):829-34.

Casey CE, Guthrie BE, Friend GM, Robinson MF. Selenium in human tissues from New Zealand. Arch Environ Health. 1982 May-Jun;37(3):133-5.

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Xia Y, Hill KE, Li P, Xu J, Zhou D, Motley AK, Wang L, Byrne DW, Burk RF. Optimization of selenoprotein P and other plasma selenium biomarkers for the assessment of the selenium nutritional requirement: a placebo-controlled, double-blind study of selenomethionine supplementation in selenium-deficient Chinese subjects. Am J Clin Nutr. 2010 Sep;92(3):525-31. doi: 10.3945/ajcn.2010.29642. Epub 2010 Jun 23.

Responsible Party:	RBurk, M.D., Vanderbilt University
ClinicalTrials.gov Identifier:	NCT00428649 History of Changes
Other Study ID Numbers:	DK58763-opt; R01DK058763 ( U.S. NIH Grant/Contract )
First Posted:	January 30, 2007
Last Update Posted:	March 7, 2012
Last Verified:	March 2012

Keywords provided by RBurk, Vanderbilt University:

Selenium supplements; Selenoprotein P; Optimization

Additional relevant MeSH terms:

Selenium; Antioxidants; Molecular Mechanisms of Pharmacological Action; Protective Agents	Physiological Effects of Drugs; Trace Elements; Micronutrients; Growth Substances