Selenium Supplementation in Youths With Autoimmune Thyroiditis
Condition: Autoimmune Thyroiditis
MeSH terms: Thyroiditis; Thyroiditis, Autoimmune; Hashimoto Disease
Study type: Interventional
Phase: Phase 4

Summary: 
      To investigate whether the supplementation of organic selenium at the "adult" dose (200 mcg
      per day in the form of L-selenomethionine) has a favorable impact on thyroid function,
      including the titer of anti-thyroid antibodies [Anti-thyroid peroxidase (anti-TPO) and
      Anti-thyroglobulin (anti-Tg) antibodies], in children and adolescents with autoimmune
      thyroiditis (AT).
    

Detailed description: 
      Background: Selenium in the form of seleno-cysteine is an essential component of enzymes that
      remove toxic substances from the body, such as glutathione peroxidase (GPX) in thyroid cells
      as well as seleno-dependent iodothyronine deiodinase that catalyses extra-thyroidal
      production of triiodothyronine (T3). In general, selenium deficiency may influence production
      of free radicals, conversion of thyroxine T4 to T3, cytokine production and immune
      mechanisms. Thus, it has been previously suggested that its supplementation may have a
      beneficial effect in patients with autoimmune thyroiditis, especially in those with increased
      inflammatory activity and a higher antibody titer. Although the two studies that have so far
      been conducted in pediatric populations demonstrated no significant effect of selenium
      administration on the titre of antibodies, the researchers did administer selenium either in
      the form of inorganic sodium selenite at the "adult" dose (100-200 mcg daily) or in the form
      of organic L-selenomethionine at the reduced dose (50 mcg daily). Therefore, to the best of
      our knowledge, selenium supplementation in the form of organic L-selenomethionine at the
      "adult" dose (200 mcg daily) has not been investigated in children and adolescents with
      autoimmune thyroiditis (AT) so far.

      Objective: Our aim is to investigate whether the supplementation of organic selenium at the
      "adult" dose (200 mcg per day in the form of L-selenomethionine) has a favorable impact on
      thyroid function, including the titer of anti-thyroid antibodies (thyroid-peroxidase antiTPO,
      and thyroglobulin -antiTg- antibodies), in children and adolescents with autoimmune
      thyroiditis (AT).

      Design and Methods: This is a randomized blinded placebo-controlled clinical trial of
      selenium supplementation versus placebo in children and adolescents with autoimmune
      thyroiditis (AT). The trial will include 100 consecutive participants (50 participants in
      each arm) from the Unit of Pediatric Endocrinology of the 4th Department of Pediatrics,
      Medical School, Aristotle University of Thessaloniki, Greece. The patients will be informed
      and given their written consent to be included in the study. The subjects will then be
      randomized to receive either organic selenium in the form of L-selenomethionine at the dose
      of 200mcg daily (intervention group) or placebo (control group) for 6 months. Both groups
      will receive oral tablets (one daily), which will be identical in appearance, taste and smell
      and will differ only in the type of active substance (L-selenomethionine or placebo). Six
      months of additional follow-up will lead to trial duration of 12 months. The experimental
      supplement will be given by the Pharmaceutical company marketing the product SEMED200®
      (INTERMED Pharmaceutical Laboratories). In all participants, determination of the
      concentrations of thyroid-stimulating hormone (TSH), free thyroxine (fT4), thyroid peroxidase
      antibodies (TPOAb), thyroglobulin antibody (TgAb) will be made at four times (0, 3, 6 and 12
      months). Thyroid volume and morphology will also be sonographically evaluated in three times
      (0, 6 and 12 months). Serum selenium levels in the form of selenomethionine will also be
      determined once (at the beginning of the study).

      Time-schedule: January- February 2015: protocol preparation. March 2015: first participant's
      first visit. March 2016: last participant's first visit. September 2016: last participant's
      last visit. September - October 2016: analysis of biological samples and data, preparation of
      manuscripts, March 2017: last participant's completion of follow-up.
    

Intervention name(s): L-selenomethionine; Placebo
Intervention type(s): Dietary Supplement; Other
Intervention description(s): The group will be randomized to receive organic selenium in the form of L-selenomethionine at the dose of 200mcg daily (intervention group) for 6 months; The group will be randomized to receive placebo (control group) for 6 months
Intervention MeSH terms: Selenium
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment