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Nutrients Nov 2023Iron deficiency (ID) is the most prevalent nutritional deficiency worldwide. Low levels of serum ferritin (SF) could affect the thyroid gland and its functioning. The... (Meta-Analysis)
Meta-Analysis Review
Iron deficiency (ID) is the most prevalent nutritional deficiency worldwide. Low levels of serum ferritin (SF) could affect the thyroid gland and its functioning. The purpose of this systematic review and meta-analysis is to summarize the main currently available evidence and analyze data on the relationship between ID and thyroid function. This study included all articles evaluating the relationship between ID and thyroid function. Quality assessment was performed using Cambridge Quality Checklists. The search strategy included the following combination of Medical Subjects Headings terms and keywords: "iron deficiency", "thyroid function", "thyroid disease", "thyroid dysfunction", and "hypothyroidism". A meta-analysis was performed to evaluate whether thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) levels differed between patients with ID and healthy controls without ID. For statistical comparison between cases and controls, the mean difference (MD) was calculated, and a subgroup analysis of pregnant and non-pregnant women was performed. Cochran's Q testing and heterogeneity indices () were used to assess statistical heterogeneity. Sensitivity analysis and publication bias analyses were also performed, both qualitatively and quantitatively. Finally, a meta-regression analysis was performed to evaluate the correlation between serum TSH or FT4 levels and SF in the study population. Ten cross-sectional studies were identified and reviewed. Patients with ID showed TSH (MD: -0.24 mIU/L; 95% CI -0.41, -0.07; = 100%, = 0.005), FT4 (MD: -1.18 pmol/L; 95% CI -1.43, -0.94; = 99%, < 0.000001), and FT3 (MD: -0.22 pmol/L; 95% CI -0.32, -0.12; = 99%, < 0.00001) levels that were significantly lower. Subgroup analysis confirmed significantly lower TSH, FT4, and FT3 levels in pregnant women. Non-pregnant women showed significantly lower serum FT4 and FT3 levels but no difference in TSH values. Meta-regression analysis showed that serum TSH and FT4 levels were positively correlated with SF levels. Our systematic review of the literature found that ID significantly increases the prevalence of thyroid autoantibody (anti-thyroglobulin antibodies and anti-thyroid peroxidase antibodies) positivity both individually and collectively. Studies currently published in the literature indicate a possible relationship between ID, thyroid function, and autoimmunity, especially in some patient groups. Data analysis shows that thyroid hormone levels are lower in patients with ID and, in particular, in pregnant women. Further studies are needed to understand the role played by iron in thyroid metabolism.
Topics: Humans; Female; Pregnancy; Thyroxine; Thyroid Function Tests; Cross-Sectional Studies; Thyroid Hormones; Thyroid Diseases; Thyrotropin; Iron Deficiencies
PubMed: 38004184
DOI: 10.3390/nu15224790 -
Thyroid : Official Journal of the... Mar 2024Hashimoto thyroiditis (HT) is the most common cause of hypothyroidism in iodine-sufficient areas. Selenium is an essential trace element required for thyroid hormone... (Meta-Analysis)
Meta-Analysis
Hashimoto thyroiditis (HT) is the most common cause of hypothyroidism in iodine-sufficient areas. Selenium is an essential trace element required for thyroid hormone synthesis and exerts antioxidant effects. Therefore, it may be of relevance in the management of HT. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of selenium supplementation on thyroid function (thyrotropin [TSH], free and total thyroxine [fT4, T4], free and total triiodothyronine [fT3, T3]), thyroid antibodies (thyroid peroxidase antibodies [TPOAb], thyroglobulin antibodies [TGAb], thyrotropin receptor antibody [TRAb]), ultrasound findings (echogenicity, thyroid volume), immune markers, patient-reported outcomes, and adverse events in HT. The study protocol was registered on PROSPERO (CRD42022308377). We systematically searched MEDLINE, Embase, CINHAL, Web of Science, Google Scholar, and the Cochrane CENTRAL Register of Trials from inception to January 2023 and searched citations of eligible studies. Two independent authors reviewed and coded the identified literature. The primary outcome was TSH in patients without thyroid hormone replacement therapy (THRT); the others were considered secondary outcomes. We synthesized the results as standardized mean differences (SMD) or odds ratio (OR), assessed risk of bias using the Cochrane RoB 2 tool, and rated the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We screened 687 records and included 35 unique studies. Our meta-analysis found that selenium supplementation decreased TSH in patients without THRT (SMD -0.21 [confidence interval, CI -0.43 to -0.02]; 7 cohorts, 869 participants; = 0%). In addition, TPOAb (SMD -0.96 [CI -1.36 to -0.56]; 29 cohorts; 2358 participants; = 90%) and malondialdehyde (MDA; SMD -1.16 [CI -2.29 to -0.02]; 3 cohorts; 248 participants; = 85%) decreased in patients with and without THRT. Adverse effects were comparable between the intervention and control groups (OR 0.89 [CI 0.46 to 1.75]; 16 cohorts; 1339 participants; = 0%). No significant changes were observed in fT4, T4, fT3, T3, TGAb, thyroid volume, interleukin (IL)-2, and IL-10. Overall, certainty of evidence was moderate. In people with HT without THRT, selenium was effective and safe in lowering TSH, TPOAb, and MDA levels. Indications for lowering TPOAb were found independent of THRT.
Topics: Humans; Autoantibodies; Dietary Supplements; Hashimoto Disease; Randomized Controlled Trials as Topic; Selenium; Thyrotropin
PubMed: 38243784
DOI: 10.1089/thy.2023.0556 -
Frontiers in Endocrinology 2023In recent years, the outbreak of COVID-19 caused by SARS-CoV-2 has been witnessed globally. However, the impact of SARS-CoV-2 infection on thyroid dysfunction and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
In recent years, the outbreak of COVID-19 caused by SARS-CoV-2 has been witnessed globally. However, the impact of SARS-CoV-2 infection on thyroid dysfunction and subclinical thyroid dysfunction remains unclear. Therefore, this meta-analysis aimed to assess the effects of SARS-CoV-2 infection on thyroid dysfunction and its relationship with the severity of COVID-19.
METHODS
We systematically searched databases including PubMed, Willey Library, Embase, Web of Science, CNKI, Wanfang, and VIP. We focused on randomized controlled trials, case-control studies, and cohort studies published between December 2019 and August 2023, examining the association between SARS-CoV-2 infection and hypothyroidism, with a specific emphasis on the severity of the infection. The quality of the research was assessed using the Newcastle-Ottawa Scale (NOS), while statistical analysis was conducted using the meta and metafor packages in R 4.2.1 software.
RESULTS
For the meta-analysis, a total of eight articles were identified based on strict inclusion and exclusion criteria. For the association between SARS-CoV-2 infection and hypothyroidism, three studies (266 samples) comparing TSH levels of COVID-19 and control groups showed no difference in TSH levels [SMD=-0.04,95%CI(-1.22,1.15),]. Additionally, two studies examining TT3 (a sample of 176 cases) and two studies examining TT4 (a sample of 176 cases) also showed no difference in TT3 and TT4 between the COVID-19 group and the control group, respectively. However, when evaluating the severity of COVID-19, six studies (565 samples) showed that TSH in the severe group was significantly lower than in the mild group [SMD = -0.55, 95% CI (-0.96, -0.14)], while FT3 was also lower in the severe group [SMD = -0.96, 95% CI (-1.24, -0.67)]. No noticeable differences were observed between the severe and mild groups in their TT3, FT4, and TT4 levels.
CONCLUSION
SARS-CoV-2 infection may have detrimental effects on thyroid function in individuals with severe symptoms. More research is needed to confirm and explore this relationship.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023486042.
Topics: Humans; COVID-19; SARS-CoV-2; Hypothyroidism; Thyroid Diseases; Thyrotropin
PubMed: 38111709
DOI: 10.3389/fendo.2023.1291774 -
Cancers Aug 2023(1) Background: Radiotherapy (RT) is a central component for the treatment of many head and neck cancers. In this systematic review of the literature, we aimed to... (Review)
Review
(1) Background: Radiotherapy (RT) is a central component for the treatment of many head and neck cancers. In this systematic review of the literature, we aimed to characterize and quantify the published evidence on RT-related hypothyroidism, including estimated incidence, clinical risk factors, and dosimetric parameters that may be used to guide clinical decision making. Furthermore, we aimed to identify potential areas of improvement in the prevention and clinical management of RT-induced hypothyroidism, including the role of modern advanced therapeutic techniques. (2) Methods: We conducted a systemic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. PubMed and Google Scholar were searched to identify original research articles describing the incidence, mechanism, dosimetry, treatment, or prevention of radiation-related hypothyroidism for adults receiving RT for the treatment of head and neck cancers. The snowball method was used to identify additional articles. For identified articles, we tabulated several datapoints, including publication date, patient sample size, estimated hypothyroidism incidence, cancer site/type, follow-up period, radiation modality and technique, use of multimodality therapy, method of thyroid function evaluation, and proposed dosimetric predictors of hypothyroidism. (3) Results: One hundred and eleven articles met inclusion criteria, reflecting a range of head and neck cancer subtypes. There was a large variation in the estimated incidence of RT-related hypothyroidism, with a median estimate of 36% (range 3% to 79%). Reported incidence increased in later publication dates, which was likely related to improved screening and longer follow up. There were a wide variety of predictive metrics used to identify patients at high risk of hypothyroidism, the most common of which were volumetric and mean dosimetrics related to the thyroid gland (Vxx%, Dmean). More recently, there has been increasing evidence to suggest that the thyroid gland volume itself and the volume of the thyroid gland spared from high-dose radiation (VSxx) may better predict thyroid function after RT. There were no identified studies investigating the role of advanced radiotherapeutic techniques such as MRI-guided RT or particle therapy to decrease RT-related hypothyroidism. Conclusions: Hypothyroidism is a common toxicity resulting from therapeutic radiation for head and neck cancer with recent estimates suggesting 40-50% of patients may experience hypothyroidism after treatment. Dosimetric predictive models are increasingly able to accurately identify patients at risk of hypothyroidism, especially those utilizing thyroid VS metrics. Further investigation regarding the potential for advanced radiotherapeutic therapies to decrease RT-induced thyroid dysfunction is needed.
PubMed: 37686597
DOI: 10.3390/cancers15174321 -
BMC Public Health Sep 2023Knowledge surrounding the association between exposure to pesticides and hypothyroidism is inconsistent and controversial. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Knowledge surrounding the association between exposure to pesticides and hypothyroidism is inconsistent and controversial.
METHODS
The aim of present study was, therefore, to review scientific evidence systematically and conduct a meta-analysis into the contribution of exposure to pesticides to hypothyroidism. PubMed, Scopus, Web of Science, and Google Scholar were searched. The findings are presented as OR, HR, PR, IRR, and 95% confidence interval (95%CI). A fixed-effect model using the inverse-variance method and random-effects inverse-variance model with DerSimonian-Laird method were used for estimating the pooled estimates. Cochran Q and I tests were used to confirm the heterogeneity of selected studies.
RESULTS
Twelve studies were included in the systematic review, and 9 studies in the meta-analysis. Epidemiological evidence suggested that exposure to insecticides including organochlorines, organophosphates, and pyrethroids increased risk of hypothyroidism (adjusted odds ratio (aOR) = 1.23, 95%CI = 1.14, 1.33 for organochlorines, aOR = 1.12, 95%CI = 1.07, 1.17 for organophosphates, aOR = 1.15, 95%CI = 1.03, 1.28 for pyrethroids). Exposure to herbicides also increased risk of hypothyroidism (aOR = 1.06, 95%CI = 1.02, 1.10). However, exposure to fungicides and fumigants was not found to be associated with hypothyroidism.
CONCLUSION
To increase current knowledge and confirm evidence to date future research needs to center on large-scale longitudinal epidemiological and biological studies, examination of dose-response relationships, the controlling of relevant confounding variables, using standardized and high sensitivity tools, and investigating the effects of environmental exposure.
Topics: Humans; Pesticides; Insecticides; Environmental Exposure; Hypothyroidism; Pyrethrins
PubMed: 37752464
DOI: 10.1186/s12889-023-16721-5 -
The Journal of Maternal-fetal &... Dec 2023This study aimed to explore the effects of levothyroxine on pregnancy outcomes and thyroid function in recurrent pregnancy loss (RPL) women with subclinical... (Meta-Analysis)
Meta-Analysis Review
Effect of levothyroxine on the pregnancy outcomes in recurrent pregnancy loss women with subclinical hypothyroidism and thyroperoxidase antibody positivity: a systematic review and meta-analysis.
OBJECTIVE
This study aimed to explore the effects of levothyroxine on pregnancy outcomes and thyroid function in recurrent pregnancy loss (RPL) women with subclinical hypothyroidism (SCH) or thyroperoxidase antibody positivity (TPOAb).
METHODS
Literature search was performed from inception to 24 June 2022. The heterogeneity for each outcome was evaluated using Cochran's test and quantified with I-squared (). Pooled effect sizes were expressed as relative risk (RR) and weighted mean differences (WMD) with 95% confidence intervals (95% CIs). Stability of the results were assessed using the sensitivity analysis.
RESULTS
Fifteen eligible studies with 1911 participants were included in this meta-analysis. The pooled data showed that levothyroxine decreased premature delivery rate (RR = 0.48, 95%CI: 0.32, 0.72), miscarriage rate (RR = 0.59, 95%CI: 0.44, 0.79), premature rupture of membranes (PROM) rate (RR = 0.44, 95%CI: 0.29, 0.66), and fetal growth restriction rate (RR = 0.33, 95%CI: 0.12, 0.89) in RPL women with TPOAb. In RPL women with SCH, live birth rate was elevated (RR = 1.20, 95%CI: 1.01, 1.42) and miscarriage rate was reduced (RR = 0.65, 95%CI: 0.44, 0.97) by levothyroxine. In addition, levothyroxine substantially decreased TSH level (WMD = -0.23, 95% CI: -0.31, -0.16) and TPO level (WMD = -23.48, 95%CI: -27.50, -19.47).
CONCLUSIONS
Levothyroxine improved pregnancy outcomes and thyroid function in RPL women with TPOAb or SCH, indicating that levothyroxine may be beneficial for RPL women if TPOAb or SCH occurs. Future studies are needed to verify our findings.
Topics: Pregnancy; Female; Humans; Thyroxine; Pregnancy Outcome; Hypothyroidism; Premature Birth; Abortion, Habitual
PubMed: 37433649
DOI: 10.1080/14767058.2023.2233039 -
Advances in Radiation Oncology 2023The aim of this study was to comprehensively review all studies examining clinical outcomes of craniospinal irradiation with proton radiotherapy for medulloblastoma (MB)... (Review)
Review
PURPOSE
The aim of this study was to comprehensively review all studies examining clinical outcomes of craniospinal irradiation with proton radiotherapy for medulloblastoma (MB) to determine whether theoretical dosimetric advantages have translated into superior clinical outcomes (including survival and toxicities) compared with traditional photon-based techniques.
METHODS AND MATERIALS
We performed a systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles reporting on clinical outcomes of pediatric and/or adult patients with MB treated with proton radiotherapy were included. Evidence quality was assessed using a modified Newcastle Ottawa scale and GRADE score.
RESULTS
Thirty-five studies were included, with a total of 2059 patients reported (representing an estimated 630-654 unique patients). None of the studies were randomized, 12 were comparative, 9 were prospective, 3 were mixed, and 22 were retrospective. Average mean/median follow-up was 5.0 years (range, 4 weeks to 12.6 years). The majority of studies (n = 19) reported on treatment with passive scatter proton beams exclusively. Average study quality was 6.0 out of 9 (median, 6; standard deviation, 1.6). Nine studies scored ≥8 out of 9 on the modified Newcastle Ottawa Scale; an overall "moderate" GRADE score was assigned. Well-designed comparative cohort studies with adequate follow-up demonstrate superior neurocognitive outcomes, lower incidence of hypothyroidism (23% vs 69%), sex hormone deficiency (3% vs 19%), greater heights, and reduced acute toxicities in patients treated with protons compared to photons. Overall survival (up to 10 years), progression-free survival (up to 10 years), brain stem injury, and other endocrine outcomes were similar to those reported for photon radiation. There was insufficient evidence to make conclusions on endpoints of quality of life, ototoxicity, secondary malignancy, alopecia, scoliosis, cavernomas, and cerebral vasculopathy.
CONCLUSIONS
Moderate-grade evidence supports proton radiotherapy as a preferred treatment for craniospinal irradiation of MB based on equivalent disease control and comparable-to-improved toxicity versus photon beam radiation therapy.
PubMed: 37008255
DOI: 10.1016/j.adro.2023.101189 -
Endocrine May 2024To assess the prospective association between metabolic syndrome (MetS), its components, and incidence of thyroid disorders by conducting a systematic review and... (Meta-Analysis)
Meta-Analysis
PURPOSE
To assess the prospective association between metabolic syndrome (MetS), its components, and incidence of thyroid disorders by conducting a systematic review and meta-analysis.
METHODS
A systematic search was performed in Ovid Medline, Embase.com, and Cochrane CENTRAL from inception to February 22, 2023. Publications from prospective studies were included if they provided data on baseline MetS status or one of its components and assessed the incidence of thyroid disorders over time. A random effects meta-analysis was conducted to calculate the odds ratio (OR) for developing thyroid disorders.
RESULTS
After full-text screening of 2927 articles, seven studies met our inclusion criteria. Two of these studies assessed MetS as an exposure (N = 71,727) and were included in our meta-analysis. The association between MetS at baseline and incidence of overt hypothyroidism at follow-up yielded an OR of 0.78 (95% confidence interval [CI]: 0.52-1.16 for two studies, I = 0%). Pooled analysis was not possible for subclinical hypothyroidism, due to large heterogeneity (I = 92.3%), nor for hyperthyroidism, as only one study assessed this association. We found evidence of an increased risk of overt (RR: 3.10 (1.56-4.64, I = 0%) and subclinical hypothyroidism (RR 1.50 (1.05-1.94), I = 0%) in individuals with obesity at baseline. There was a lower odds of developing overt hyperthyroidism in individuals with prediabetes at baseline (OR: 0.68 (0.47-0.98), I = 0%).
CONCLUSIONS
We were unable to draw firm conclusions regarding the association between MetS and the incidence of thyroid disorders due to the limited number of available studies and the presence of important heterogeneity in reporting results. However, we did find an association between obesity at baseline and incidence of overt and subclinical hypothyroidism.
Topics: Humans; Metabolic Syndrome; Incidence; Thyroid Diseases; Hypothyroidism
PubMed: 37688711
DOI: 10.1007/s12020-023-03503-7 -
Medicine Dec 2023Hashimoto's thyroiditis (HT) is the prevailing form of autoimmune thyroiditis and the leading cause of hypothyroidism in iodine-sufficient regions worldwide. This study... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Hashimoto's thyroiditis (HT) is the prevailing form of autoimmune thyroiditis and the leading cause of hypothyroidism in iodine-sufficient regions worldwide. This study aims to evaluate the efficacy of vitamin D supplementation on HT through a meta-analysis of randomized controlled trials (RCTs).
METHODS
The databases searched included PubMed, and others. We included RCTs that the treatment group received vitamin D, while the control group received either a placebo or no treatment. The studies measured the baseline and endpoint levels of 25-hydroxyvitamin D [25(OH)D], thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), anti-thyroid peroxidase antibody (TPO-Ab), and thyroglobulin antibody (TG-Ab). We performed a meta-analysis to calculate the standardized mean difference (SMD) and 95% confidence interval (CI).
RESULTS
A total of 12 studies involving 862 individuals were included. Vitamin D supplementation has a significant impact on reducing the titers of TPO-Ab (SMD = -1.084, 95% CI = -1.624 to -0.545) and TG-Ab (SMD = -0.996, 95% CI = -1.579 to -0.413) in patients with HT, and it also improves thyroid function by decreasing TSH level (SMD = -0.167, 95% CI = -0.302 to 0.031) and increasing FT3 (SMD = 0.549, 95% CI = 0.077-1.020) and FT4 (SMD = 0.734, 95% CI = 0.184-1.285) levels. Active vitamin D (calcitriol) significantly reduces the titer of TPO-Ab compared to naive forms of vitamin D (vitamin D2 or D3); treatment durations > 12 weeks result in a more effective reduction of TPO-Ab levels and a more significant increase in FT4 and FT3 levels in patients with HT (meta-regression P < .05).
CONCLUSION
Vitamin D supplementation may have beneficial effects on HT patients by modulating immune responses and improving thyroid function.
Topics: Humans; Autoantibodies; Dietary Supplements; Hashimoto Disease; Thyrotropin; Vitamin D
PubMed: 38206745
DOI: 10.1097/MD.0000000000036759 -
Ear, Nose, & Throat Journal Aug 2023Thyroid nodules are common entities, with 5% malignancy. Differentiated thyroid cancer represents 90% of thyroid malignancies, with papillary carcinoma being the most... (Review)
Review
Effectiveness and Safety of Percutaneous Treatment in Lesions Suggestive of Thyroid Cancer (Bethesda V and VI-T1aN0M0) Compared to Surgical Treatment: Systematic Review and Meta-Analysis.
INTRODUCTION
Thyroid nodules are common entities, with 5% malignancy. Differentiated thyroid cancer represents 90% of thyroid malignancies, with papillary carcinoma being the most common. Management is generally surgical; among its complications are injury to the recurrent laryngeal and superior laryngeal nerve, causing hoarseness, postsurgical hypoparathyroidism, hypothyroidism, and pain. Other noninvasive percutaneous interventions of thermal ablation such as microwave, radiofrequency, or laser incur lower costs and could be an option for treatment.
OBJECTIVE
To determine the effectiveness and safety of thermal ablation in lesions suspected of thyroid cancer (Bethesda V and VI/T1aN0M0) compared to surgical treatment.
METHODS
Systematic review/meta-analysis of observational studies and clinical trials. Database search includes MEDLINE/PUBMED, Embase, Scopus, Scielo, and BVS/LILACS. Studies on patients over 18 years of age with lesions suspicious of thyroid cancer were included.
RESULTS
A total of 10 studies were obtained, with 2939 patients: 1468 subjected to thermal ablation and 1471 to surgery. Regarding effectiveness, no differences were found in local recurrence [relative risk (RR) 1.17 (95% CI 0.69-1.99)] and cervical lymph node metastasis [RR 0.76 (95% CI 0.43-1.36)]. Regarding safety, infection [RR 0.29 (95% CI 0.05-1.74)], hematoma [RR 0.57 (95% CI 0.17-1.94)], and transient hoarseness [RR 0.77 (95% CI 0.39-1.51)] were evaluated, without difference. However, permanent hoarseness had significant differences in favor of thermal ablation [RR 0.29 (95% CI 0.11-0.75)].
CONCLUSIONS
Thermal ablation for the treatment of T1aN0M0 papillary thyroid carcinoma is equally effective when compared to surgical techniques and offers a better safety profile, particularly in permanent hoarseness.
PubMed: 37605444
DOI: 10.1177/01455613231189067