0
selected
-
1.
Are probiotics, prebiotics, and synbiotics beneficial in primary thyroid diseases? A systematic review with meta-analysis.
Zawadzka, K, Kałuzińska, K, Świerz, MJ, Sawiec, Z, Antonowicz, E, Leończyk-Spórna, M, Abadi, AK, Trofimiuk-Müldner, M, Bała, MM
Annals of agricultural and environmental medicine : AAEM. 2023;30(2):217-223
-
-
-
Free full text
Plain language summary
Irregularities in intestinal microbial composition are thought to be correlated with thyroid dysfunction. Supplementation of prebiotics, probiotics and synbiotics are gaining momentum in recent times in improving health in general. This systematic review of randomised controlled trials was conducted to summarise the up-to-date evidence on the therapeutic potential of prebiotics, probiotics and synbiotics in the treatment of thyroid disease. The meta-analysis did not show beneficial effects on thyroid hormone balance, BMI or levothyroxine dosage reduction. Supplementation with Lactobacillus and Bifidobacterium resulted in improvement in constipation and a statistically non-significant reduction in thyroid-stimulating hormone in adult participants with hypothyroidism. Further robust long-term studies are required to evaluate the efficacy of prebiotics, probiotics and synbiotics in thyroid disease treatment as the availability of the number of studies included in this systematic review was limited. However, healthcare professionals can use the review to understand the current evidence in this area and the correlation between gut microbial alterations and thyroid disease.
Abstract
INTRODUCTION AND OBJECTIVE A number of studies indicate the presence of a thyroid-gut axis and the important influence of the gut microbiota on thyroid function. As prebiotics, probiotics and synbiotics show therapeutic potential in the treatment of intestinal dysbiosis, the aim of this review is to evaluate the efficacy of their supplementation in primary thyroid diseases. REVIEW METHODS Electronic databases (Ovid MEDLINE, Embase, CENTRAL), registers of clinical trials, and grey literature up to 6 October 2022 were searched for randomised controlled trials (RCTs) meeting pre-specified inclusion criteria. The protocol was registered in PROSPERO (CRD42021235054). BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE After screening 1,721 references, two RCTs were identified, which included 136 hypothyroid participants in total. Meta-analysis of the results after eight weeks of supplementation with predominantly Lactobacillus and Bifidobacterium strains indicated a clinically and statistically nonsignificant decrease in TSH (MD -0.19 mIU/L; 95% CI -0.43 to 0.06; I2= 0%), and no effect on fT3 levels (MD 0.01 pg/mL; 95% CI-0.16 to 0.18; I2= 0%). Data from single studies indicated no significant change in the levels of fT4, thyroid auto-antibodies, BMI, levothyroxine doses, and severity of symptoms measured with validated scales. Only constipation scores showed significant improvement (MD -8.71 points in the Faecal Incontinence Questionnaire; 95% CI -15.85 to -1.57; I2= 0%). SUMMARY Low-certainty evidence from two randomised trials, suggests that routine administration of probiotics, prebiotics or synbiotics may result in little to no benefit in patients with primary hypothyroidism.
-
2.
Do Dietary Supplements Affect Inflammation, Oxidative Stress, and Antioxidant Status in Adults with Hypothyroidism or Hashimoto's Disease?-A Systematic Review of Controlled Trials.
Kubiak, K, Szmidt, MK, Kaluza, J, Zylka, A, Sicinska, E
Antioxidants (Basel, Switzerland). 2023;12(10)
-
-
-
Free full text
Plain language summary
A deficiency of the thyroid hormone causes hypothyroidism (HT), whereas Autoimmune thyroiditis (AIT) is mainly an organ-specific autoimmune condition. Both HT and AIT are characterised by low-grade inflammation and inflammation in the thyroid gland. Dietary supplements may offer health benefits; however, previous research findings are inconclusive. This systematic review evaluated twenty-two controlled studies to understand the effectiveness of dietary supplements in reducing inflammation and oxidative stress and improving antioxidant and thyroid parameters in patients with HT or AIT. The efficacy of dietary supplements in improving thyroid health and reducing inflammation and oxidative stress was inconclusive due to the low quality of the included studies and the limited number of available studies. Selenium supplements might be beneficial in improving thyroid parameters and inflammation in patients with HT or AIT. Even though the therapeutic benefits of dietary supplements in treating thyroid disease were inconclusive, healthcare professionals can use them to address the common nutritional deficiencies in people with HT and AIT. Further, large, long-term, robust studies are required to assess the therapeutic utility of different dietary supplements in promoting the health of the thyroid gland.
Abstract
This systematic review aims to summarise the results of controlled trials on dietary supplements (DS) usage and inflammation, oxidative stress, antioxidant status, and thyroid parameter improvement in hypothyroidism (HT)/Hashimoto's thyroiditis (AIT) patients. The study protocol was registered with PROSPERO (no. CRD42022365149). A comprehensive search of the PubMed, Scopus, and Web of Science databases resulted in the identification of nineteen randomised controlled trials and three non-randomised studies for the review; three studies examined the effect of supplementation with vitamin D, twelve studies-with selenium, and seven studies-with other DS. Based on very limited evidence, the lack of influence of vitamin D supplementation on inflammatory parameters was found, while no studies have examined oxidative stress and antioxidant status parameters, and only one provided results for a single thyroid parameter after an intervention. Some evidence was found proving that selenium supplementation may decrease inflammation and improve thyroid parameters, but reaching a conclusion about its influence on oxidative stress and antioxidant status is not possible because of the insufficient number of studies. Additionally, due to examining other DS (e.g., multicomponent, Nigella sativa, and genistein) only in single studies, conclusions cannot be drawn. Further long-term, high-quality randomised controlled trials are necessary to better understand the influence of DS on inflammation, oxidative stress, and antioxidant status, as well as their potential to improve thyroid gland function in HT/AIT patients.
-
3.
Effect of selenium on thyroid autoimmunity and regulatory T cells in patients with Hashimoto's thyroiditis: A prospective randomized-controlled trial.
Hu, Y, Feng, W, Chen, H, Shi, H, Jiang, L, Zheng, X, Liu, X, Zhang, W, Ge, Y, Liu, Y, et al
Clinical and translational science. 2021;14(4):1390-1402
-
-
-
-
Free full text
-
Plain language summary
Hashimoto thyroiditis (HT) is the most common thyroid autoimmune disease. Multiple factors contribute to the development of the disease leading to immune system-mediated destruction of the thyroid gland. In the absence of specific therapeutic approaches that address the immunological activity, thyroid hormone replacement is the primary treatment. Selenium (Se) is an essential trace element for humans and the thyroid gland utilises high amounts of selenium for the production of enzymes and antioxidants. Supplementing Se has shown positive effects in HT, as demonstrated in some studies. Yet, there have been inconsistencies in the results and the understanding of the mechanisms involved are limited. The authors of this prospective, randomized controlled study tried to shed some light on the efficacy of Se supplementation and its mechanisms. 43 HT-patients on no thyroid medication, received 200mcg Se per day for 6 months. Various markers were assessed including antibodies, thyroid stimulating hormone (TSH), antioxidant enzymes and T-helper immune cells that regulate immunological activity, which were compared to the HT-control group (n=47) and healthy individuals (n=36). The outcome of the intervention showed that Se supplementation can reduce thyroid antibodies, and TSH and can increase antioxidant enzymes in patients with HT and along with the findings the authors discussed some potential mechanisms at play. This study suggests that supplementary Se can benefit HT, particularly subclinical HT.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Selenium supplementation is reported to reduce TPOAb, TGAb, and TSH levels, as well as increase Se, GPx3, and SePP1 concentrations in patients with HT without the use of levothyroxine replacement.
- Practitioners could consider selenium supplementation in patients with HT who have serum selenium levels less than 120ug/L.
Evidence Category:
-
X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
A prospective randomised controlled trial was conducted to investigate the effect of selenium (Se) supplementation in patients with Hashimoto’s thyroiditis (HT). The study also explored the potential mechanisms of action of Selenium in thyroid autoimmunity.
One hundred and twenty-six subjects (90 with HT and 36 healthy individuals) were included in the study. The patients with HT were randomly assigned into two groups. The Se-treated group (n=43) received 200ug of selenium in a selenious yeast tablet (SYT) per day for 6 months. No treatment was given to the control group (n=47). At the endpoint, 126/126 subjects completed the study.
Primary clinical outcomes were:
- Antithyroid peroxidase antibodies (TPOAb) levels were significantly lower compared with the control group at 6 months (ΔTPOAb [IU/ml] = −28.4 [−103.9,0] vs. 0 [−18.1, 20.5], p = 0.001).
- There was a significant difference in antithyroglobulin antibodies TGAb titers between the Se-treated group and the control group at 6 months (ΔTGAb [IU/ml] = −48.8 [−139.7, −2.0] vs. 18.3 [−23.5, 77.4], p = 0.001.
- Compared with baseline, thyroid stimulating hormone (TSH) presented slightly lower levels in the Se-treated group, whereas there was a statistical increase in the control group at 6 months (ΔTSH [mIU/L] = −0.16 [−2.1, 0.28] vs. 0.48 [−0.15, 1.47], p = 0.001).
Secondary clinical outcomes were:
- aTreg cells in the Se-treated group were significantly higher than the control group at 6 months (13.19 ± 3.5 vs. 11.49 ± 2.79, p = 0.012)
- There was a pronounced increase in glutathione peroxidase (GPx3) at 6 months of treatment in the Se-treated group compared with the control group (p=0.028).
- Furthermore, Selenoprotein P1 (SePP1) levels increased in the Se-treated group compared with the control group at 6 months (17.2 [9.8, 22.1] vs. 10.7 [8.9, 14.6], p = 0.007).
Clinical practice applications:
- There is no specific approach to suppress autoimmunity, thus thyroxine replacement has become the generally accepted therapy for patients with Hashimoto’s thyroiditis (HT) with hypothyroidism.
- The thyroid gland contains the highest concentration of selenium, which is incorporated into selenoproteins, such as glutathione peroxidase (GPx), selenoprotein P (SePP), thioredoxin reductase, and iodothyronine deiodinases. These selenoenzymes play important roles in thyroid hormone metabolism by acting as antioxidants and immunomodulators.
- Based on this study, practitioners could therefore consider using 200ug of selenium for six months as a supportive measure specifically in patients with serum selenium levels less than 120ug/L.
Considerations for future research:
- Although about 20 studies have investigated the treatment of selenium in HT further research is warranted to help explore the appropriate use of selenium.
- Furthermore, investigations are needed to establish if certain HT patients could benefit more from Se supplementation.
- Additionally, investigations are needed to understand the relationship between selenium and Treg cells and their impact on thyroid antibodies.
- This study was completed over six months, longer studies are required to investigate the effect of selenium supplementation over the clinical course of HT.
Abstract
Selenium (Se) is an essential trace element in human. Recent studies of Se supplementation on the effect of Hashimoto's thyroiditis (HT) have been reported, but the exact benefit is unclear as well as the underlying immunologic mechanism. We aimed to evaluate the clinical effect of Se supplement in patients with HT, and explore the potential mechanism against thyroid autoimmunity. A prospective, randomized-controlled study was performed in patients with HT assigned to two groups. Se-treated group (n = 43) received selenious yeast tablet (SYT) for 6 months, whereas no treatment in control group (n = 47). The primary outcome is the change of thyroid peroxidase antibody (TPOAb) or thyroglobulin antibody (TGAb). Second, thyroid function, urinary iodine, Se, Glutathione peroxidase3 (GPx3), and Selenoprotein P1 (SePP1) levels were measured during the SYT treatment. Meanwhile, regulatory T cells (Tregs) and their subsets activated Tregs (aTregs), resting Tregs, and secreting Tregs, as well as Helios and PD-1 expression on these cells were also detected. The results showed that SYT treatment significantly decreased TPOAb, TGAb, and thyroid stimulating hormone (TSH) levels, accompanied with the increased Se, GPx3, and SePP1, compared with the control group. Subgroup analysis revealed that subclinical HT may benefit more from this treatment in the decrease of TSH levels by interaction test. Moreover, the percentage of aTregs, Helios/Tregs, and Helios/aTregs were significantly higher in the Se-treated group than control. In conclusion, Se supplementation may have a beneficial effect on thyroid autoantibodies and thyroid function by increasing the antioxidant activity and upregulating the activated Treg cells.
-
4.
The correlation between selenium levels and autoimmune thyroid disease: a systematic review and meta-analysis.
Zuo, Y, Li, Y, Gu, X, Lei, Z
Annals of palliative medicine. 2021;10(4):4398-4408
-
-
-
Free full text
Plain language summary
Autoimmune thyroid disease (AITD) encompasses several autoimmune conditions affecting the thyroid gland. Genetics, environmental and lifestyle factors influence the condition. Part of the clinical presentation is an abnormal function of the thyroid and the presence of antibodies against thyroid proteins, such as antithyroglobulin antibody (TGAb) and anti-thyroid peroxidase antibody (TPOAb). Selenium is a trace mineral essential to the human body and an important building block for a particular family of proteins called Selenoproteins. This protein family exerts enzymatic functions and plays a major role in thyroid health, furthermore, also in hormone synthesis and managing oxidative stress. Previous research noted that supplemental selenium had beneficial effects on thyroid hormones and antibodies. This systematic review and meta-analysis sought to collectively examine the effect of selenium supplementation on hormone and antibody levels in people with AITD. Blood values investigated were TSH (thyroid stimulating hormone), FT3 (free triiodothyronine), FT4 (Thyroxine), TPOAb, and TGAb. The review included 17 randomised controlled trials, with a total of 1,095 subjects with AITD, plus controls. The cumulated results demonstrated that selenium can notably decrease blood levels of FT3, FT4, and TPOAb in patients with AITD. However, levels of TSH and TGAb seemed not to be significantly affected by selenium supplementation. The authors highlighted that the review was not specific to a particular AITD and that there was limited literature available concerning TGAb levels. More research is needed to clarify the benefits of selenium in AITD.
Abstract
BACKGROUND This investigation systematically evaluated the selenium levels and the effects of selenium supplementation in patients with autoimmune thyroid disease (AITD). METHODS Randomized controlled trials (RCTs) related to selenium supplementation in patients with AITD were selected from the PubMed, Medline, Web of Sciences, Embase, Cochrane Library, and Spring databases. All related literature published between January 2000 and November 2020 were included. The RCT bias risk assessment was conducted according to the Cochrane Handbook 5.0.2. The Review Manager 5.3 software was applied for meta-analysis of the included literature. RESULTS A total of 17 articles meeting the requirements were selected, including a total of 1,911 subjects. Meta-analysis results showed that the serum free triiodothyronine (FT3) levels in patients was greatly reduced after selenium supplementation compared to placebo treatment (MD =-0.40; 95% confidential interval (CI): -0.70--0.10; Z=2.61; P=0.009). Serum free thyroxine (FT4) levels and anti-thyroid peroxidase antibody (TPOAb) levels were also significantly reduced (MD = -0.76; 95% CI: -1.58--0.07; Z=1.79; P=0.07), and anti-thyroid peroxidase antibody (TPOAb) level was decreased observably (MD =-150.25; 95% CI: -04.06--96.43; Z=5.47; P<0.00001). The thyroid stimulating hormone (TSH) levels (MD =0.06; 95% CI: -0.53-0.66; Z=0.21; P=0.83) and anti-thyroglobulin antibody (TGAb) levels (MD =17.19; 95% CI: -254.86-289.25; Z=0.12; P=0.90) were not significantly different between the experimental group and the control group. CONCLUSIONS Selenium-containing drugs were effective in treating AITD patients, and greatly reduced the levels of FT3, FT4, and TPOAb in AITD patients. These results suggested that selenium level had a great effect on AITD and selenium supplementation showed a very important effect on AITD.
-
5.
A lecithin phosphatidylserine and phosphatidic acid complex (PAS) reduces symptoms of the premenstrual syndrome (PMS): Results of a randomized, placebo-controlled, double-blind clinical trial.
Schmidt, K, Weber, N, Steiner, M, Meyer, N, Dubberke, A, Rutenberg, D, Hellhammer, J
Clinical nutrition ESPEN. 2018;24:22-30
-
-
-
Free full text
Plain language summary
PMS is characterized by a cluster of somatic and psychological symptoms of varying severity. These symptoms occur only during the luteal phase of the menstrual cycle and resolve during the first days of menses. Recent observational data suggest that supplementation with Lipogen's phosphatidylserine and phosphatidic acid complex (PAS) alleviates these PMS symptoms. The aim of this study was to observe the effects of PAS on PMS symptom severity. This study is a prospective, randomised, placebo-controlled, double-blind single centre study with two arms (PAS or placebo). Participants were randomly assigned to one of the two groups. Results show beneficial effects of a daily intake of PAS over 3 cycles on symptom levels as assessed by several well-recognized instruments for PMS evaluation. The PAS complex alleviated the PMS symptoms, providing a safe alternative to standard pharmacological treatment. Authors conclude that their findings merit consideration of developing the PAS complex as a botanical drug for treatment of PMS symptoms.
Abstract
BACKGROUND & AIMS Many women experience emotional and physical symptoms around the time of ovulation and more so before menstruation interfering with their daily normal life also known as premenstrual syndrome (PMS). Recent observational data suggest that supplementation with Lipogen's phosphatidylserine (PS) and phosphatidic acid (PA) complex (PAS) alleviates these PMS symptoms. The aim of this study was to confirm these observations on the effects of PAS on PMS symptom severity within a controlled clinical trial setting. METHODS Forty women aged 18-45 years with a diagnosis of PMS were assigned to either take PAS (containing 400 mg PS & 400 mg PA per day) or a matching placebo. The study comprised 5 on-site visits including 1 baseline menstrual cycle followed by 3 treatment cycles. Treatment intake was controlled for by using an electronic device, the Medication Event Monitoring System (MEMS®). Primary outcome of the study was the PMS symptoms severity as assessed by using the Daily Record of Severity of Problems (DRSP). Further, SIPS questionnaire (a German version of the Premenstrual Symptoms Screening Tool (PSST)), salivary hormone levels (cortisol awakening response (CAR) and evening cortisol levels) as well as serum levels (cortisol, estradiol, progesterone and corticosteroid binding globulin (CBG)) were assessed. RESULTS PMS symptoms as assessed by the DRSP Total score showed a significantly better improvement (p = 0.001) over a 3 cycles PAS intake as compared to placebo. In addition, PAS treated women reported a greater improvement in physical (p = 0.002) and depressive symptoms (p = 0.068). They also reported a lower reduction of productivity (p = 0.052) and a stronger decrease in interference with relationships with others (p = 0.099) compared to the placebo group. No other DRSP scale or item showed significant results. Likewise, the reduction in the number of subjects fulfilling PMS or premenstrual dysphoric disorder (PMDD) criteria as classified by the SIPS did not differ between the PAS and the placebo group. For the biomarkers, the salivary cortisol percentage increase of the CAR was significantly less pronounced in the follicular phase of cycle 4 than in the follicular phase of cycle 1 for subjects taking PAS when compared to subjects taking placebo (p = 0.018). Furthermore, the change of serum cortisol levels between visit 1 and visit 5 differed significantly between groups (p = 0.043). While serum cortisol levels of PAS treated females slightly decreased between visit 1 and visit 5, cortisol levels of females treated with placebo increased. For all other biomarkers, no treatment effects were observed over the 4 cycles study period. Overall, this study confirms that a daily intake of PAS, containing 400 mg PS and 400 mg PA, can be considered as safe. CONCLUSIONS Results substantiate the efficacy of PAS in reducing symptoms of PMS. In view of the recent inclusion of severe PMS symptoms (PMDD) in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the positive results of this clinical study merits consideration of developing the PAS complex as a botanical drug for treatment of PMDD. CLINICAL TRIAL REGISTRATION The study is registered at Deutsches Register Klinischer Studien with the registration number DRKS00009005.
-
6.
Thyroid hormones and changes in body weight and metabolic parameters in response to weight loss diets: the POUNDS LOST trial.
Liu, G, Liang, L, Bray, GA, Qi, L, Hu, FB, Rood, J, Sacks, FM, Sun, Q
International journal of obesity (2005). 2017;41(6):878-886
-
-
-
Free full text
-
Plain language summary
The role of thyroid hormones in diet-induced weight loss and subsequent weight regain is largely unknown. The aim of this study was to examine the associations between thyroid hormones and changes in body weight and resting metabolic rate (RMR) in adults on a calorie-restricted diet. Data analysis was conducted among 569 overweight and obese adults with normal thyroid function participating in the 2-year Prevention of Obesity Using Novel Dietary Strategies (POUNDS) LOST clinical trial. Participants were assigned to diets that represented a reduced caloric intake of 750 kcal/day from estimated energy needs. Changes in body weight and RMR were assessed during the 2-year intervention. Thyroid hormones (free triiodothyronine (T3), free thyroxine (T4), total T3, total T4 and thyroid-stimulating hormone (TSH)), anthropometric measurements and biochemical parameters were assessed at baseline, 6 months and 24 months. Participants lost an average of 6.6 kg of body weight during the first 6 months and subsequently regained an average of 2.7 kg of body weight over the remaining period from 6 to 24 months. Baseline free T3, total T3 and free T4 were associated with baseline body weight, body mass index and RMR. Total T4 and TSH were not associated with these parameters. Higher baseline free T3 and free T4 levels were significantly associated with a greater weight loss during the first 6 months. Thyroid hormones did not predict weight regain in 6-24 months. In addition, changes in free T3 and total T3 levels were positively associated with changes in body weight, RMR, body fat mass, blood pressure, glucose, insulin, triglycerides and leptin at 6 months and 24 months. The authors concluded that on a reduced-calorie diet, higher baseline free T3 and free T4 predicted more weight loss, but not weight regain among overweight and obese adults with normal thyroid function. These findings reveal a role of thyroid hormones in body weight regulation and may help identify individuals more responsive to weight loss diets.
Abstract
BACKGROUND The role of thyroid hormones in diet-induced weight loss and subsequent weight regain is largely unknown. OBJECTIVES To examine the associations between thyroid hormones and changes in body weight and resting metabolic rate (RMR) in a diet-induced weight loss setting. SUBJECTS/METHODS Data analysis was conducted among 569 overweight and obese participants aged 30-70 years with normal thyroid function participating in the 2-year Prevention of Obesity Using Novel Dietary Strategies (POUNDS) LOST randomized clinical trial. Changes in body weight and RMR were assessed during the 2-year intervention. Thyroid hormones (free triiodothyronine (T3), free thyroxine (T4), total T3, total T4 and thyroid-stimulating hormone (TSH)), anthropometric measurements and biochemical parameters were assessed at baseline, 6 months and 24 months. RESULTS Participants lost an average of 6.6 kg of body weight during the first 6 months and subsequently regained an average of 2.7 kg of body weight over the remaining period from 6 to 24 months. Baseline free T3 and total T3 were positively associated, whereas free T4 was inversely associated, with baseline body weight, body mass index and RMR. Total T4 and TSH were not associated with these parameters. Higher baseline free T3 and free T4 levels were significantly associated with a greater weight loss during the first 6 months (P<0.05) after multivariate adjustments including dietary intervention groups and baseline body weight. Comparing extreme tertiles, the multivariate-adjusted weight loss±s.e. was -3.87±0.9 vs -5.39±0.9 kg for free T3 (Ptrend=0.02) and -4.09±0.9 vs -5.88±0.9 kg for free T4 (Ptrend=0.004). The thyroid hormones did not predict weight regain in 6-24 months. A similar pattern of associations was also observed between baseline thyroid hormones and changes in RMR. In addition, changes in free T3 and total T3 levels were positively associated with changes in body weight, RMR, body fat mass, blood pressure, glucose, insulin, triglycerides and leptin at 6 months and 24 months (all P<0.05). CONCLUSIONS In this diet-induced weight loss setting, higher baseline free T3 and free T4 predicted more weight loss, but not weight regain among overweight and obese adults with normal thyroid function. These findings reveal a novel role of thyroid hormones in body weight regulation and may help identify individuals more responsive to weight loss diets.