Optimization of Selenoprotein P in Chinese Subjects

Study Overview
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Brief Summary
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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

Detailed Description
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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.

Official Title
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Optimization of Selenoprotein P in Chinese Subjects

Conditions
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Selenium Deficiency

Intervention / Treatment
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* 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


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>20 µg selenium as selenomethionine | Dietary Supplement: 20 µg selenium<br>* 20 µg selenium as selenomethionine<br>|
| Experimental: 2<br>40 µg selenium as selenomethionine | Dietary Supplement: 40 µg selenium<br>* 40 µg selenium as selenomethionine<br>|
| Experimental: 3<br>60 µg selenium as selenomethionine | Dietary Supplement: 60 µg selenium<br>* 60 µg selenium as selenomethionine<br>|
| Experimental: 4<br>80 µg selenium as selenomethionine | Dietary Supplement: 80 µg selenium<br>* 80 µg selenium as selenomethionine<br>|
| Experimental: 5<br>100 µg selenium as selenomethionine | Dietary Supplement: 100 µg selenium<br>* 100 µg selenium as selenomethionine<br>|
| Experimental: 6<br>120 µg selenium as selenomethionine | Dietary Supplement: 120 µg selenium<br>* 120 µg selenium as selenomethionine<br>|
| Placebo Comparator: 7<br>placebo | Dietary Supplement: placebo<br>* placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma selenoprotein P levels at 0, 4, 8, 12, 16, 20, 24, 32, and 40 weeks |  | 40 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total plasma selenium concentrations at 0, 4, 8, 12, 16, 20, 24, 32, and 40 weeks |  | 40 weeks | 
| Plasma glutathione peroxidase activity at 0, 4, 8, 12, 16, 20, 24, 32, and 40 weeks |  | 40 weeks | 
| 24hr urinary selenium excretion at 0, 20 and 40 weeks |  | 40 weeks | 
| Hair selenium levels at 0, 20 and 40 weeks |  | 40 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Selenium supplements, Selenoprotein P, Optimization