The chronic autoimmune thyroiditis quality of life selenium trial (CATALYST): study protocol for a randomized controlled trial.
BACKGROUND
Patients with chronic autoimmune thyroiditis have impaired health-related quality of life. The thyroid gland has a high selenium concentration, and specific selenoprotein enzyme families are crucial to immune function, and catalyze thyroid hormone metabolism and redox processes in thyroid cells. Previous randomized controlled trials have found that selenium supplementation decreases thyroid-disease-specific antibody levels. We hypothesize that selenium might be beneficial in the treatment of chronic autoimmune thyroiditis.


METHODS
The CATALYST trial is an investigator-initiated randomized, blinded, multicentre clinical trial of selenium supplementation versus placebo in patients with chronic autoimmune thyroiditis.


METHODS
age ≥18 years; serum thyroid peroxidase antibody level ≥100 IU/ml within the previous 12 months; treatment with levothyroxine and written informed consent.


METHODS
previous diagnosis of toxic nodular goitre, Graves' hyperthyroidism, postpartum thyroiditis, Graves' orbitopathy; previous antithyroid drug treatment, radioiodine therapy or thyroid surgery; immune-modulatory or other medication affecting thyroid function; pregnancy, planned pregnancy or breastfeeding; allergy towards any intervention or placebo component; intake of selenium supplementation >55 μg/day; inability to read or understand Danish or lack of informed consent. The trial will include 2 × 236 participants. The experimental intervention and control groups will receive 200 μg selenium-enriched yeast or matching placebo tablets daily for 12 months. The experimental supplement will be SelenoPrecise®. The primary outcome is thyroid-related quality of life assessed by the Thyroid Patient-Reported Outcome (ThyPRO) questionnaire. Secondary outcomes include serum thyroid peroxidase antibody concentration; serum triiodothyronine/thyroxine ratio; levothyroxine dosage; adverse reactions and serious adverse reactions and events.


CONCLUSIONS
In this pragmatic trial, participating patients follow their usual treatment at their usual hospitals. In order to collect high-quality data on the clinical course and quality of life, and to minimize missing data, an elaborate trial management system has been designed. 12 months intervention duration was selected in consideration of the primary outcome, thyroid-related quality of life.


BACKGROUND
ClinicalTrials.gov ID: NCT02013479.
Department of Endocrinology and Metabolism, Odense University Hospital Kloevervaenget 4-6, DK-5000 Odense C, Odense, Denmark. kristian.winther@rsyd.dk.
Kristian Hillert
KH
Winther
Torquil
T
Watt
Jakob Bue
JB
Bjørner
Per
P
Cramon
Ulla
U
Feldt-Rasmussen
Christian
C
Gluud
Jeppe
J
Gram
Mogens
M
Groenvold
Laszlo
L
Hegedüs
Nils
N
Knudsen
Åse Krogh
ÅK
Rasmussen
Steen Joop
SJ
Bonnema
D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D002986:Clinical Trials as Topic; D003718:Denmark; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008297:Male; D011788:Quality of Life; D012107:Research Design; D012643:Selenium / Q000627:therapeutic use*; D011795:Surveys and Questionnaires; D013961:Thyroid Gland / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D013963:Thyroid Hormones / Q000097:blood; D013967:Thyroiditis, Autoimmune / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology / Q000523:psychology; D013997:Time Factors; D016896:Treatment Outcome; D015002:Yeast, Dried / Q000627:therapeutic use*
D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D033862:Iron-Binding Proteins; D013963:Thyroid Hormones; C056658:TPO protein, human; D007453:Iodide Peroxidase; D012643:Selenium