Effect of Selenium Supplementation on Glycemic Control in Patients With Type 2 Diabetes or Prediabetes

Study Overview
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Brief Summary
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Although it has been suggested that selenium (Se) increases the risk of T2DM, most evidence comes from observational studies that cannot prove causality. A systematic review assessed randomized clinical trials and found that the risk of T2DM was not greater in those randomized to Se supplementation than in those randomized to placebo. Se is a toxic element in animals and humans, and overexposure to Se has also been linked to detrimental health effects in humans. Previous studies were mostly conducted in Se-sufficient areas. Moreover, the effectiveness of low-dose Se supplementation on participants with elevated glycemic status was unknown. This cross-over, double blinded, randomized controlled trail aimed to investigate the effectiveness of Se supplementation for glucose control among participants with diabetes or prediabetes. Moreover, we also aimed to examine whether selenoprotein P genotypes, Se-related gut microbiota and their related metabolite modified the effectiveness.

Official Title
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Effect of Selenium Supplementation on Glycemic Control in Patients With Type 2 Diabetes or Prediabetes: a Double Blinded, Randomized Controlled Trail

Conditions
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Type 2 Diabetes, PreDiabetes

Intervention / Treatment
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* Dietary Supplement: Se-yeast
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: FPG ≥ 5.6 mmol/L; HbA1c ≥ 5.7%; OGTT 2h or postprandial blood glucose ≥ 7.8 mmol/L. T2D patients with stable anti-diabetic medication and blood glucose controlled well for 4 weeks prior. Exclusion Criteria: Under 30 years old or above 70 years old; Pregnancy; Major surgery in the previous 6 months or planned to occur during the trail; Insulin injection for diabetes; Suffering from severe obesity (BMI > 40 kg/m2), immunodeficiency syndrome, thyroid disease, coronary heart disease, stroke, malignant neoplasm, kidney or liver disease, or other serious diseases, such as mental illness; Reduced kidney function (GFR < 60 mL/min/1.73m2, creatinine > 1.2 times the normal upper limit [male, > 133.2 μmol/L; female > 100 μmol/L]); Systolic or diastolic blood pressure greater than 160 or 100 mmHg; Taking dietary supplements (e.g., selenium, vitamin, fish oil, etc.) for nearly one month before the intervention; Taking antibiotics or probiotics within 12 weeks of screening.

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Se-yeast<br>Selenium-enriched yeast tablet (Se, 50 μg/d) | Dietary Supplement: Se-yeast<br>* The participants will be asked to take Se-yeast tablet. The intervention period is about 3 months. Do not take any other medicine, traditional Chinese medicine, or dietary supplements.<br>|
| Placebo Comparator: Placebo<br>placebo-yeast tablet | Dietary Supplement: Placebo<br>* The participants will be asked to take placebo-yeast tablet. The intervention period is about 3 months. Do not take any other medicine, traditional Chinese medicine, or dietary supplements.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of HbA1c concentration | Change of glycated hemoglobin concentration | 0 week, 4th week, 8th week, and 12th week in the intervention period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of FPG concentration | Change of fasting plasma glucose concentration | 0 week, 4th week, 8th week, and 12th week in the intervention period | 
| Change of FPI concentration | Change of fasting plasma insulin concentration | 0 week, 4th week, 8th week, and 12th week in the intervention period | 
| Change of HOMA-IR | Change of homeostasis model of assessment-insulin resistance | 0 week, 4th week, 8th week, and 12th week in the intervention period | 
| Change of TG concentration | Change of serum triglyceride concentration | 0 week, 4th week, 8th week, and 12th week in the intervention period | 
| Change of TC concentration | Change of total cholesterol concentration | 0 week, 4th week, 8th week, and 12th week in the intervention period | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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prediabetes, selenium, Type 2 Diabetes