The chronic autoimmune thyroiditis quality of life selenium trial (CATALYST): study protocol for a randomized controlled trial Selenium supplementation could restore euthyroidism in subclinical hypothyroid patients with autoimmune thyroiditis. Selenium and the thyroid: A close-knit connection Effects of Selenium Supplementation on Spontaneous Autoimmune Thyroiditis in NOD.H-2h4 Mice. Selenium supplementation in patients with autoimmune thyroiditis decreases thyroid peroxidase antibodies concentrations. [The effect of selenium therapy on autoimmune thyroiditis]. Selenium supplementation for patients with Graves’ hyperthyroidism (the GRASS trial): study protocol for a randomized controlled trial Does selenium supplementation affect thyroid function? Results from a randomized, controlled, double-blinded trial in a Danish population. Effect of low-dose selenium on thyroid autoimmunity and thyroid function in UK pregnant women with mild-to-moderate iodine deficiency Randomized controlled trial of the effect of selenium supplementation on thyroid function in the elderly in the United Kingdom. The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies. Effects of a six month treatment with selenomethionine in patients with autoimmune thyroiditis. Effects of selenomethionine supplementation on selenium status and thyroid hormone concentrations in healthy adults. A randomized-controlled, double-blind study of the impact of selenium supplementation on thyroid autoimmunity and inflammation with focus on the GPx1 genotypes Selenium in the treatment of autoimmune thyroiditis Multicenter, Phase III Trial Comparing Selenium Supplementation With Observation in Gynecologic Radiation Oncology Effect of Selenium Supplementation on Recurrent Hyperthyroidism Caused by Graves' Disease: A Prospective Pilot Study.
Background Patients with chronic autoimmune thyroiditis have impaired health-related quality of life . The thyroid gl and 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 r and omized 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 / Design The CATALYST trial is an investigator-initiated r and omized , blinded , multicentre clinical trial of selenium supplementation versus placebo in patients with chronic autoimmune thyroiditis . Inclusion criteria : age ≥18 years ; serum thyroid peroxidase antibody level ≥100 IU/ml within the previous 12 months ; treatment with levothyroxine and written informed consent . Exclusion criteria : 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 underst and 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 ) question naire . Secondary outcomes include serum thyroid peroxidase antibody concentration ; serum triiodothyronine/thyroxine ratio ; levothyroxine dosage ; adverse reactions and serious adverse reactions and events . Discussion 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 design ed . 12 months intervention duration was selected in consideration of the primary outcome , thyroid-related quality of life . Trial registration Clinical Trials.gov ID : NCT02013479 INTRIDUCTION The thyroid is an organ with one of the highest selenium concentrations , containing many selenoproteins implicated in thyroid hormone metabolism . Treatment with levothyroxine has been recommended for all sub clinical hypothyroid patients with TSH levels > 10 mU/L , whereas for those with TSH < 10 mU/L treatment remains controversial . AIM A r and omised controlled prospect i ve study was performed to investigate the effects of Se treatment on patients with autoimmune thyroiditis and mild sub- clinical hypothyroidism ( TSH < 10 mU/L ) . MATERIAL AND METHODS A total of 196 patients with autoimmune thyroiditis were recruited in the study . Patients were assigned to receive ( case ) or not receive ( control ) an oral selenomethionine treatment . Cases received 83 mcg selenomethionine/day orally for four months . All the patient 's charts were su bmi tted to thyroid hormonal profile ( TSH , fT4 ) and TPOAb evaluation upon enrolment and at the end of the study . RESULTS In total 192 patients completed the study . Cases and controls were superimposable for age , gender , thyroid hormonal profile , and TPOAb levels . At the end of the study , 33/192 ( 17.2 % ) participants restored euthyroidism ( Responders ) . Responders were significantly more frequent among Cases than Controls ( 30/96 [ 31.3 % ] vs. 3/96 [ 3.1 % ] , p < 0.0001 ) . CONCLUSION Selenium supplementation could restore euthyroidism in one third of sub clinical hypothyroidism patients with autoimmune thyroiditis . ( Endokrynol Pol 2016 ; 67 ( 6 ) : 567 - 571 ) Introduction : In areas with severe selenium deficiency higher incidence of thyroiditis has been reported due to a decreased activity of selenium-dependent glutathione peroxidase enzyme within thyroid cells . Aims and Objective : To study the effect of selenium supplementation in patients with autoimmune thyroid disease . Material s and Methods : This is a blinded placebo-controlled prospect i ve study done in 60 patients with autoimmune thyroid disease ( as defined by an anti-thyroid peroxidase antibody ( TPOAb ) level more than 150 IU/ml ) irrespective of the baseline thyroid status . Patients with overt hyperthyroidism who are on antithyroid drugs , patients on any other medication , which may alter the immunity status of the patients , and pregnant patients were excluded from the study . Patients were r and omized into two age and TPOAb-matched groups ; 30 patients  received 200 μg of sodium selenite/day , orally , for 3 months , and 30 patients  received placebo . All hypothyroid patients were given l-thyroxine replacement . Results : Of 30 patients in the selenium treated group , 6 patients were overtly hypothyroid , 15 were sub clinical hypothyroid , 6 were euthyroid , and 3 were sub clinical hyperthyroid . The mean TPOAb concentration decreased significantly by 49.5 % ( P < 0.013 ) in the selenium treated group versus 10.1 % ( P < 0.95 ) in the placebo-treated group . Conclusion : Selenium substitution has a significant impact on inflammatory activity in thyroid-specific autoimmune disease . It would be of interest to determine whether early treatment with selenium in patients with newly developed autoimmune thyroiditis may delay or even prevent the natural course of these diseases BACKGROUND Recent clinical studies have demonstrated the suppressive effect of selenium ( Se ) treatment on serum thyroid-specific antibody titers in patients with autoimmune thyroiditis ( AIT ) , but the mechanism underlying this process is not clear . The aim of the present study was to investigate the effects of selenium on the incidence and severity of AIT , titers of thyroid autoantibodies , and selenoprotein expression in thyroid in a spontaneous autoimmune thyroiditis ( SAT ) model . METHODS NOD.H-2(h4 ) mice at four weeks of age were r and omly divided into control , iodine supplement ( SAT ) , and selenium supplement groups ( SAT+Se ) . Mice were given 0.005 % sodium iodide water for eight weeks to induce SAT and then 0.3 mg/L sodium selenite in drinking water for 8 weeks and 16 weeks . The severity of lymphocytic infiltration in the thyroid , serum thyroglobulin antibody ( TgAb ) titers , serum selenium concentration , expression of glutathione peroxidase-1 ( GPx1 ) , thioredoxin reductase-1 ( Txnrd1 ) , and peroxiredoxin 5 were measured . RESULTS Serum selenium concentration significantly increased after selenium supplementation . Serum TgAb levels were significantly lower in the selenium group compared with the SAT group ( p<0.05 ) . The prevalence of thyroiditis and the degree of infiltration of lymphocytes decreased gradually over time in the group provided with selenium supplementation . The expression of GPx1 and Txnrd1 by Western blotting were found to be significantly higher in the SAT+Se group than in other groups ( p<0.05 ) . CONCLUSIONS These results indicate that selenium treatment can increase the function of antioxidation by upregulating the expression of selenoproteins in the thyroid and have an inhibitory effect on TgAb titers , which may have an impact on AIT In areas with severe selenium deficiency there is a higher incidence of thyroiditis due to a decreased activity of selenium-dependent glutathione peroxidase activity within thyroid cells . Selenium-dependent enzymes also have several modifying effects on the immune system . Therefore , even mild selenium deficiency may contribute to the development and maintenance of autoimmune thyroid diseases . We performed a blinded , placebo-controlled , prospect i ve study in female patients ( n = 70 ; mean age , 47.5 + /- 0.7 yr ) with autoimmune thyroiditis and thyroid peroxidase antibodies ( TPOAb ) and /or Tg antibodies ( TgAb ) above 350 IU/ml . The primary end point of the study was the change in TPOAb concentrations . Secondary end points were changes in TgAb , TSH , and free thyroid hormone levels as well as ultrasound pattern of the thyroid and quality of life estimation . Patients were r and omized into 2 age- and antibody (TPOAb)-matched groups ; 36 patients received  200 microg ( 2.53 micromol ) sodium selenite/d , orally , for 3 months , and 34 patients  received placebo . All patients were substituted with L-T(4 ) to maintain TSH within the normal range . TPOAb , TgAb , TSH , and free thyroid hormones were determined by commercial assays . The echogenicity of the thyroid was monitored with high resolution ultrasound . The mean TPOAb concentration decreased significantly to 63.6 % ( P = 0.013 ) in the selenium group vs. 88 % ( P = 0.95 ) in the placebo group . A subgroup analysis of those patients with TPOAb greater than 1200 IU/ml revealed a mean 40 % reduction in the selenium-treated patients compared with a 10 % increase in TPOAb in the placebo group . TgAb concentrations were lower in the placebo group at the beginning of the study and significantly further decreased ( P = 0.018 ) , but were unchanged in the selenium group . Nine patients in the selenium-treated group had completely normalized antibody concentrations , in contrast to two patients in the placebo group ( by chi(2 ) test , P = 0.01 ) . Ultrasound of the thyroid showed normalized echogenicity in these patients . The mean TSH , free T(4 ) , and free T(3 ) levels were unchanged in both groups . We conclude that selenium substitution may improve the inflammatory activity in patients with autoimmune thyroiditis , especially in those with high activity . Whether this effect is specific for autoimmune thyroiditis or may also be effective in other endocrine autoimmune diseases has yet to be investigated UNLABELLED Selenium as an essential trace element is capable of exerting complex effects on the endocrine and immune system by its antioxidant capacity . The role of selenium is important because the level of free oxygen radicals is elevated in the physiological thyroid hormone synthesis . THE AIM OF STUDY was to determine whether selenium therapy can influence the level of antithyroid peroxidase and antithyroglobulin antibodies or whether there is a correlation between antioxidant capacity and the titer of autoantibodies . METHOD 132 patient with autoimmune thyroiditis were investigated in a prospect i ve , blind and placebo-controlled study . L-thyroxine substitution therapy was made in both groups and the level of TSH remained in the normal range . The selenium-treated group ( n = 70 patients , 68 female , mean age 41,4 + /- 9,5 year ) was compared with the placebo-treated group ( n = 62 patients , 61 female , mean age 42,7 + /- 8,3 year ) . Selenium therapy was continued by L-seleno-methionine ( per os 2 x 100 microg/day ) for one year . Determination of TSH , fT4 , fT3 and autoantibodies was carried out by chemiluminescence method . Total antioxidant capacity was determined by R and ox kit , the level of selenium in the sera by atomic absorption technique was measured . In the follow-up study , patients were controlled every third month and at the end of a one-year observation period . RESULTS The level of selenium in the untreated patients was significantly lower than in treated patients and controls . The fT3/fT4 ration proved to be higher in patients after selenium therapy . The titer of antithyroid antibodies ( mostly the antithyroid peroxidase ) significantly decreased at the end of the study . An inverse correlation was found between antioxidant capacity and the level of antithyroid peroxidase antibodies . The volume of thyroid gl and slightly diminished in treated patients . Side effects were not observed . CONCLUSIONS Selenium completed with L-thyroxine is a suitable therapy for patients with autoimmune thyroiditis Background Graves ’ hyperthyroidism is an autoimmune disease causing hyperfunction of the thyroid gl and . The concentration of selenium is high in the thyroid gl and and two important groups of enzymes within the thyroid are selenoproteins , that is , they depend on selenium . Selenium may have beneficial effects on autoimmune hypothyroidism and on Graves ' orbitopathy , but the effects of selenium on Graves ' hyperthyroidism is unknown . We hypothesize that adjuvant selenium may be beneficial in the treatment of Graves ' hyperthyroidism . The objective is to investigate if selenium supplementation plus st and ard treatment with anti-thyroid drugs versus st and ard treatment with anti-thyroid drugs will lead to a decrease in anti-thyroid drug treatment failure ( that is , failure to remain euthyroid , without further treatment , one year after cessation of anti-thyroid drug treatment ) , faster and longer lasting remission ( that is , anti-thyroid drug treatment success ) , and improved quality of life in patients with Graves ’ hyperthyroidism . Methods and design The trial is an investigator-initiated , r and omised , blinded , multicentre clinical trial . Inclusion criteria are : age 18 years or older ; diagnosis of active Graves ' hyperthyroidism within the last two months ; and informed consent . Exclusion criteria are major co-morbidity ; previous radioactive iodine treatment ; ongoing anti-thyroid drug treatment for more than two months ; treatment with immunomodulatory drugs ; known allergy towards the components in the selenium and placebo pills ; pregnancy or breast-feeding ; and intake of selenium supplementation above 70 μg per day . We plan to include 492 participants , r and omised ( 1:1 ) to two tablets of 100 μg selenium once daily for the 24 to 30 months intervention period versus two identical placebo tablets once daily . The primary outcome is the proportion of participants with anti-thyroid drug treatment failure ( see above ) at the end of the intervention period ( 24 to 30 months ) . Secondary outcomes are : thyroid-specific quality of life during the first year after r and omisation ; level of thyroid stimulating hormone-receptor antibodies at 18 months after r and omisation and at the end of the intervention period ( 24 to 30 months ) ; hyperthyroid symptoms during the first year after r and omisation ; eye symptoms during the first year after r and omisation , and at the end of the intervention period ( 24 to 30 months ) ; adverse reactions during the intervention period ; and serious adverse events during the intervention period . Discussion It was of great importance to the initiators of this trial , that the results would be directly applicable to daily clinical practice . Therefore , it was design ed as a pragmatic trial : the patients follow their usual treatment at their usual hospitals . In order to still collect high quality data on the clinical course and quality of life , an elaborate trial management system was design ed to keep track of patient input , need for trial personnel input and action , and to collect data from medical chart systems . Meticulous follow-up on missing responses to the QoL measurements has been incorporated into the system , to minimise missing quality of life data . Monitoring of adverse reactions and events is achieved by thorough instruction of the participants , surveillance of patient-reported outcomes , and integration with national data bases regarding hospitalizations . A very long intervention period was necessary , since patients are not considered in remission until one year after stopping anti-thyroid drugs . Usually , patients are treated for 12 to 18 months with anti-thyroid drugs , yielding a total intervention period of 24 to 30 months . Trial registration Clinical Trials.gov : NCT01611896 OBJECTIVE Selenium is present in the active site of proteins important for thyroid hormone synthesis and metabolism . The objective of this study is to investigate the effect of selenium supplementation in different doses on thyroid function , under conditions of suboptimal dietary selenium intake . DESIGN The Danish PREvention of Cancer by Intervention with SElenium pilot study ( DK-PRECISE ) is a r and omized , double-blinded , placebo-controlled trial . A total of 491 males and females aged 60 - 74 years were r and omized to 100 μg ( n=124 ) , 200 μg ( n=122 ) , or 300 μg ( n=119 ) selenium-enriched yeast or matching yeast-based placebo tablets ( n=126 ) . A total of 361 participants , equally distributed across treatment groups , completed the 5-year intervention period . METHODS Plasma sample s were analyzed for selenium and serum sample s for TSH , free triiodothyronine ( FT3 ) , and free thyroxine ( FT4 ) at baseline , and after 6 months , and 5 years of supplementation . RESULTS Plasma selenium concentrations increased significantly and dose-dependently in treatment groups receiving selenium ( P<0.001 ) . Serum TSH and FT4 concentrations decreased significantly and dose-dependently by 0.066 mIU/l ( P=0.010 ) and 0.11 pmol/l ( P=0.015 ) , respectively , per 100 μg/day increase , with insignificant differences between 6 months and 5 years . No significant effects were found for FT3 and FT3:FT4 ratio . CONCLUSIONS In euthyroid subjects , selenium supplementation minutely and dose-dependently affects thyroid function , when compared with placebo , by decreasing serum TSH and FT4 concentrations . Based on these findings , selenium supplementation is not warranted under conditions of marginal selenium deficiency . However , a role for selenium supplementation in the treatment of autoimmune thyroid diseases is still unresolved Purpose Selenium is an essential trace mineral and a component of selenoproteins that are involved in the production of thyroid hormones and in regulating the immune response . We aim ed to explore the effect of low-dose selenium supplementation on thyroid peroxidase antibody ( TPO-Ab ) concentration and thyroid function in pregnant women from a mild-to-moderate iodine-deficient population . Methods Sample s and data were from a secondary analysis of Selenium in PRegnancy INTervention ( SPRINT ) , a double-blind , r and omized , placebo-controlled study that recruited 230 women with singleton pregnancies from a UK antenatal clinic at 12 weeks of gestation . Women were r and omized to receive 60 µg/day selenium or placebo until delivery . Serum thyroid peroxidase antibodies ( TPO-Ab ) , thyrotropin ( TSH ) and free thyroxine ( FT4 ) were measured at 12 , 20 and 35 weeks and thyroglobulin antibodies ( Tg-Ab ) at 12 weeks . Results 93.5 % of participants completed the study  . Se supplementation had no more effect than placebo in decreasing TPO-Ab concentration or the prevalence of TPO-Ab positivity during the course of pregnancy . In women who were either TPO-Ab or Tg-Ab negative at baseline ( Thy-Ab−ve ) , TSH increased and FT4 decreased significantly throughout gestation ( P < 0.001 ) , with no difference between treatment groups . In women who were Thy-Ab+ve at baseline , TSH tended to decrease and was lower than placebo at 35 weeks ( P = 0.050 ) . FT4 fell more on Se than placebo supplementation and was significantly lower at 35 weeks ( P = 0.029 ) . Conclusions Low-dose selenium supplementation in pregnant women with mild-to-moderate deficiency had no effect on TPO-Ab concentration , but tended to change thyroid function in Thy-Ab+ve women BACKGROUND Thyroid function depends on the essential trace mineral selenium , which is at the active center of the iodothyronine deiodinase enzymes that catalyze the conversion of the prohormone thyroxine ( T(4 ) ) to the active form of thyroid hormone , triiodothyronine ( T(3 ) ) . OBJECTIVE Because selenium intake in the United Kingdom has fallen during the past 25 y , we wanted to determine whether current selenium status might be limiting conversion of T(4 ) to T(3 ) in the elderly , in whom marginal hypothyroidism is relatively common . DESIGN We investigated the effect of selenium supplementation in a double-blind , placebo-controlled trial in 501 elderly UK volunteers . Similar numbers of men and women from each of 3 age groups , 60 - 64 y , 65 - 69 y , and 70 - 74 y , were r and omly allocated to receive 100 , 200 , or 300 microg Se/d as high-selenium yeast or placebo yeast for 6 mo . As part of the study , plasma selenium , thyroid-stimulating hormone , and total and free T(3 ) and T(4 ) were measured . Data from 368 euthyroid volunteers who provided blood sample s at baseline and 6 mo were analyzed . RESULTS Although selenium status at baseline correlated weakly with free T(4 ) ( r = -0.19 , P < 0.001 ) and with the ratio of free T(3 ) to free T(4 ) ( r = 0.12 , P = 0.02 ) , we found no evidence of any effect of selenium supplementation on thyroid function , despite significant increases in plasma selenium . However , baseline plasma selenium in our study ( x : 91 microg/L ) was somewhat higher than in previous supplementation studies in which apparently beneficial effects were seen . CONCLUSION We found no indication for increasing selenium intake to benefit T(4 ) to T(3 ) conversion in the elderly UK population CONTEXT Pregnant women who are positive for thyroid peroxidase antibodies [ TPOAb(+ ) ] are prone to develop  postpartum thyroid dysfunction ( PPTD ) and permanent hypothyroidism .  Selenium ( Se ) decreases thyroid inflammatory activity in patients with autoimmune thyroiditis . OBJECTIVE We examined whether Se supplementation , during and after pregnancy , influences the thyroidal autoimmune pattern and function . DESIGN This was a prospect i ve , r and omized , placebo-controlled study . SETTING The study was conducted in the Department of Obstetrics and Gynecology and Department of Endocrinology . PATIENTS A total of 2143 euthyroid pregnant women participated in the study ; 7.9 % were TPOAb(+ ) . INTERVENTIONS During pregnancy and the postpartum period , 77 TPOAb(+ ) women received selenomethionine 200 microg/d ( group S1 ) , 74 TPOAb(+ ) women received placebo ( group S0 ) , and 81 TPOAb(- ) age-matched women were the control group ( group C ) . MAIN OUTCOME MEASURES We measured the prevalence of PPTD and hypothyroidism . RESULTS PPTD and permanent hypothyroidism were significantly lower in group S1 compared with S0 ( 28.6 vs. 48.6 % , P<0.01 ; and 11.7 vs. 20.3 % , P<0.01 ) . CONCLUSION Se supplementation during pregnancy and in the postpartum period reduced thyroid inflammatory activity and the incidence of hypothyroidism OBJECTIVE Selenium ( Se ) in the form of selenocysteine is an essential component of the family of the detoxifying enzymes glutathione peroxidase ( Gpx ) and of the iodothyronine selenodeiodinases that catalyse the extrathyroidal production of tri-iodothyronine ( T(3 ) ) . Thus , Se deficiency may seriously influence the generation of free radicals , the conversion of thyroxine ( T(4 ) ) to T(3 ) and the autoimmune process . Therefore , we performed a r and omised , placebo-controlled prospect i ve study to investigate the effects of Se treatment on patients with autoimmune thyroiditis ( AIT ) . DESIGN AND METHODS Sixty five patients aged 22 - 61 years ( median age 48 years ) with AIT were recruited into two groups . Group I ( Gr I ) ( n=34 ) was treated with selenomethionine ( Seme ) 200 microg , plus L-thyroxine ( LT(4 ) ) to maintain TSH levels between 0.3 - 2.0 mU/l , whereas group II ( Gr II ) ( n=31 ) received LT(4 ) plus placebo over a period of 6 months . Moreover , the pharmacokinetics of Seme  were studied in 10 patients and eight volunteers at baseline and 2 h , 4 h , 6 h and 24 h after oral administration of a 200 microg tablet of Seme . Finally , Se levels were measured at the end of the study in some patients of both groups and their results were correlated with thyroid hormone levels . RESULTS In the pharmacokinetics study , basal serum concentration of Se ( 75+/-6 microg/l ) was within the reference range ( 70 - 125 microg/l ) , it promptly increased at 2 h , peaked at 4 h ( 147+/-17 microg/l ; P<0.0001 ) and it was abundant in serum at 24 h. In Gr I , antibodies against thyroid peroxidase ( anti-TPO ) levels showed an overall decrease of 46 % at 3 months ( from 1875+/-1039 U/l to 1013+/-382 U/l ; P<0.0001 ) and of 55.5 % at 6 months . In Gr II the overall decrease of anti-TPO amounted to 21 % at 3 months and to 27 % at 6 months ( from 1758+/-917 U/l to 1284+/-410 U/l ; P<0.005 ) . There were no significant changes of antibodies against thyroglobulin levels between the groups . At the end of this study Se levels were found to be statistically significantly increased in Gr I ( n = 9/34 ) compared with Gr II ( n=11/31 ) ( 97+/-8.4 vs 79+/-8 ; P<0.01 ) but no correlation with thyroid hormone was found . CONCLUSIONS Seme is proven to be rapidly absorbed by the gastrointestinal tract . It appears to be useful as adjunctive therapy with LT(4 ) in the treatment of AIT . The exact mechanism(s ) is not very well determined , it might enhance the activity of detoxifying enzymes and enforce the defense against oxidative stress BACKGROUND Selenium , a potential cancer prevention agent currently being tested against prostate cancer in the Selenium and Vitamin E Cancer Prevention Trial ( SELECT ) , plays an integral role in thyroid metabolism . The effects of long-term selenium supplementation on thyroid hormone concentrations are unknown . OBJECTIVE The objective was to investigate the effects of long-term selenium supplementation on thyroid hormone concentrations . DESIGN Twenty-eight healthy adults took 200 microg selenomethionine/d for 28 mo . The thyroid hormones triiodothyronine ( T3 ) , thyroxine ( T4 ) , and thyrotropin ( TSH ) were measured in plasma for 4 mo before supplementation and quarterly during supplementation . The assay methods were changed mid study ; the results of the 2 methods were not comparable . Therefore , one analysis was conducted based on the results of the first method , and a second analysis was based on all of the data , adjusted for the change . Serial data collection permitted a test for trends rather than simply a difference between initial and final values . RESULTS By 9 mo , mean ( + /-SEM ) plasma selenium concentrations had increased from 1.78 + /- 0.07 micromol/L at baseline to 2.85 + /- 0.11 micromol/L for men and from 1.64 + /- 0.04 to 3.32 + /- 0.1.2 micromol/L for women . T3 concentrations in men increased 5 % per year ( P = 0.01 ) . T4 and TSH concentrations were unchanged . CONCLUSIONS Selenium supplementation produced no clinical ly significant changes in thyroid hormone concentrations . A small but statistically significant increase in T3 concentrations was noted in men , with no corresponding decreases in TSH . A subset of SELECT subjects might be monitored periodically for changes during long-term selenium supplementation Purpose To analyze the impact of selenium supplementation on serum antiTPO levels and thyroid echogenicity in patients with CAT , evaluating the response in subgroups with different GPx1 genotypes . Methods CAT patients ( n = 55 ) with positive antiTPO were r and omized to selenomethionine ( SeMet ) 200 μg daily ( n = 28 ) or placebo ( n = 27 ) for 3 months . Assessment s included GPx1 genotyping at baseline and serum levels of plasma selenium , erythrocyte GPx1 activity , antiTPO and thyroid echogenicity at baseline , and 3 and 6 months . Results In the SeMet group , the increase in plasma levels of selenium and erythrocyte GPx1 activity was similar among patients with different GPx1 genotypes . In the overall cohort , patients r and omized to SeMet showed a 5 % decrease in antiTPO levels at 3 months ( p = non-significant ) and 20 % at 6 months ( p < 0.001 versus 3 months ) . In contrast , patients in the placebo group did not show significant changes in antiTPO levels at any time point . Subgroup analysis showed that patients with different GPx1 genotypes presented comparable responses in antiTPO levels and echogenicity index to SeMet . Conclusions Selenium supplementation decreased serum antiTPO levels in CAT patients , with similar response among patients with different GPx1 genotypes We recently conducted a prospect i ve , placebo‐controlled clinical study , where we could demonstrate , that a substitution of 200 μg sodium selenite for three months in patients with autoimmune thyroiditis reduced thyroid peroxidase antibody ( TPO‐Ab ) concentrations significantly . Forty‐seven patients from the initially 70 patients agreed to participate in a follow‐up cross‐over study for further six months . One group ( n = 13 ) , which initially received selenium continued to take 200 μg sodium selenite ( Se‐Se ) , one group stopped taking selenium ( Se‐0 ) ( n = 9 ) , another group which received placebo started to take 200 μg selenium ( n = 14 ) ( Plac‐Se ) and the last group was without selenium substitution ( Plac‐0 ) ( n = 11 ) . TPO‐Ab concentrations were measured at beginning and the end of the study . In the Se‐Se group , the TPO‐Ab concentrations further significantly p = 0.004 ) decreased from 625 ± 470 U/ml to 354 ± 321 U/ml , in the Se‐0 group the TPO‐Ab concentrations increased significantly p = 0.017 ) from 450 ± 335 to 708 ± 313 U/ml . In the placebo group , the TPO‐Ab concentrations in those patients who were followed without selenium substitution were unchanged ( 1351 ± 940 vs. 1724 ± 1112 U/ml , p = 0.555 ) . In contrast , the patients who received 200 μg sodium selenite after  placebo , the TPO‐Ab concentrations decreased significantly ( p = 0.029 ) from 1182 ± 723 to 643 ± 477 U/ml Purpose . In 2010 , we reported that selenium ( Se ) supplementation during radiation therapy ( RT ) is effective for increasing blood Se levels in Se-deficient cervical and uterine cancer patients , and reduced the number of episodes and severity of RT-induced diarrhea . In the current study , we examine whether of Se supplementation during adjuvant RT affects long-term survival of these patients . Patients and Methods . Former patients were identified and question ed with respect to their health and well-being . Results . A total of 81 patients were r and omized in the initial supplementation study , 39 of whom received Se ( selenium group , SeG )  and 42 of whom served as controls ( control group , CG ) . When former patients were reidentified after a median follow-up of 70 months ( range = 0 - 136 ) , the actuarial 10-year disease-free survival rate in the SeG was 80.1 % compared to 83.2 % in the CG ( P = .65 ) , and the actuarial 10-year overall survival rate of patients in the SeG was 55.3 % compared to 42.7 % in the CG ( P = .09 ) . Conclusions . Our extended follow-up analysis demonstrates that Se supplementation had no influence on the effectiveness of the anticancer irradiation therapy and did not negatively affect patients ’ long-term survival . In view of its positive effects on RT-induced diarrhea , we consider Se supplementation to be a meaningful and beneficial adjuvant treatment in Se-deficient cervical and uterine cancer patients while undergoing pelvic radiation therapy The effect of selenium supplementation on recurrent hyperthyroidism caused by Graves ' disease is unclear . Our study aim ed to assess the efficacy of selenium supplementation therapy on recurrent Graves ' disease . Forty-one patients with recurrent Graves ' disease were enrolled in this study . All patients received the routine treatment using methimazole ( MMI ) , while patients allocated to the selenium group received additional selenium therapy for 6 months . The influence of selenium supplementation on the concentrations of thyroid stimulating hormone ( TSH ) , anti-TSH-receptor antibodies ( TRAb ) , free thyroxine ( FT4 ) , and free triiodothyronine ( FT3 ) were assessed . The remission rate was also compared between 2 groups . There was no obvious difference in the demographic data and the levels of serum FT4 , FT3 , TSH , and TRAb between the 2 groups at baseline . Both FT4 and FT3 decreased more at 2 months in the selenium group than the controls , while the TSH level increased more in patients receiving selenium supplementation ( p<0.05 ) . The TRAb level was significantly lower in patients receiving selenium supplementation ( 2.4 IU/l vs. 5.6 IU/l , p=0.04 ) . The percentages of patients with normal TRAb level at 6 months was also significantly higher in the selenium group ( 19.0 vs. 0 % , p=0.016 ) . Kaplan-Meier survival curve showed patients receiving selenium supplementation had a significantly higher rate of remission than controls ( Log-rank test p=0.008 ) . In conclusion , selenium supplementation can enhance the effect of antithyroid drugs in patients with recurrent Graves ' disease . R and omized trials with large number of participants are needed to vali date the finding above
Two systematic review s have evaluated controlled trials among patients with autoimmune thyroiditis and report that selenium supplementation decreases circulating thyroid autoantibodies .
The immunomodulatory effects of selenium might involve reducing proinflammatory cytokine release .
In Graves ’ disease , some , but not all , trials indicate that adjuvant selenium supplementation enhances the restoration of biochemical euthyroidism , and might benefit patients with mild Graves ’ orbitopathy .
The available evidence from trials does not support routine selenium supplementation in the st and ard treatment of patients with autoimmune thyroiditis or Graves ’ disease .
However , correction of moderate to severe selenium deficiency may offer benefits in preventing , as well as treating , these disorders .
Purpose of review This review provides an appraisal of recent evidence for or against selenium supplementation in patients with autoimmune thyroid diseases , and discusses possible effect mechanisms .
Recent findings Epidemiological data suggest an increased prevalence of autoimmune thyroid diseases under conditions of low dietary selenium intake .
However , clinical ly relevant effects of selenium supplementation , including improvement in quality of life , are more elusive .