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Acta Medica Portuguesa Dec 2018Subclinical hypothyroidism, defined as an increase of thyroid stimulating hormone levels with normal levels of thyroid hormones, could have a multiorgan impact. There... (Review)
Review
INTRODUCTION
Subclinical hypothyroidism, defined as an increase of thyroid stimulating hormone levels with normal levels of thyroid hormones, could have a multiorgan impact. There seem to be differences in the elderly (over 65 years of age) which indicate that there should be a different approach in terms of diagnosis and the treatment.
MATERIAL AND METHODS
Electronic database search and narrative bibliographical review.
RESULTS
Different case studies showing the multiorgan consequences of subclinical hypothyroidism suggest that, in the elderly, there is a minor impact or even a lack of repercussion, especially in those over 80 - 85 years old. Additionally, there is evidence indicating that the levels of thyroid stimulating hormone rise with the age of the patient. The standard treatment, in the beginning, is a low dose of levothyroxine when the levels of thyroid stimulating hormone are over 10.0 mIU/L, when there are noticeable symptoms or positive anti-thyroid antibodies. However, the treatment is not consensual when the levels of thyroid stimulating hormone are between 4.5 and 10.0 mIU/L, in such a way that the TRUST study concluded that no benefits have outcome from treating these patients.
DISCUSSION
The non-definition of the reference range and the age gap are the key factors that contribute the most to biased results. However, there is consensus regarding non-treatment of mild thyroid dysfunctions (4.5 - 7.0 mIU/L) in the elderly, particularly above 80 years of age. Nevertheless, for positive anti-thyroid antibodies, suggestive ultrasound changes or iatrogenic side effects, the reference level should be 4.5 mIU/L.
CONCLUSION
The general impact of subclinical hypothyroidism is different in elderly people, meaning that an individualized therapeutic approach and long-term monitoring is the appropriate strategy.
Topics: Age Factors; Aged; Aged, 80 and over; Asymptomatic Diseases; Humans; Hypothyroidism; Reference Values; Thyroid Gland; Thyroid Hormones; Thyrotropin; Thyroxine
PubMed: 30684374
DOI: 10.20344/amp.10991 -
Medicina (Kaunas, Lithuania) Aug 2022Preconception counseling is an essential tool for preventing adverse pregnancy outcomes associated with thyroid dysfunction. The high prevalence of thyroid disease among... (Review)
Review
Preconception counseling is an essential tool for preventing adverse pregnancy outcomes associated with thyroid dysfunction. The high prevalence of thyroid disease among women of reproductive age, and the increased risk of adverse pregnancy outcomes associated with thyroid dysfunction, emphasize the necessity for well-established screening and treatment criteria in the preconception period. We therefore conducted a literature review for relevant information on the screening, diagnosis and treatment of subclinical and overt hypothyroidism in women seeking pregnancy. While screening for thyroid disease is recommended only in the presence of risk factors, iodine supplementation should be recommended in most regions, with higher doses in areas with severe deficiency. Known hypothyroid women should be counseled about increasing their levothyroxine dose by 20-30% in the case of suspected or confirmed pregnancy (missed menstrual cycle or positive pregnancy test). Treating subclinical hypothyroidism appears to be beneficial, especially in the presence of autoimmunity or in patients undergoing artificial reproductive techniques. Regarding the management of TPOAb negative SCH women or euthyroid women with positive TPOAb, further research is necessary in order to make evidence-based recommendations.
Topics: Autoimmunity; Counseling; Female; Humans; Hypothyroidism; Pregnancy; Thyroid Diseases; Thyroxine
PubMed: 36013589
DOI: 10.3390/medicina58081122 -
The Journal of Clinical Endocrinology... Jun 2015The objective was to determine the risk of stroke associated with subclinical hypothyroidism. (Review)
Review
OBJECTIVE
The objective was to determine the risk of stroke associated with subclinical hypothyroidism.
DATA SOURCES AND STUDY SELECTION
Published prospective cohort studies were identified through a systematic search through November 2013 without restrictions in several databases. Unpublished studies were identified through the Thyroid Studies Collaboration. We collected individual participant data on thyroid function and stroke outcome. Euthyroidism was defined as TSH levels of 0.45-4.49 mIU/L, and subclinical hypothyroidism was defined as TSH levels of 4.5-19.9 mIU/L with normal T4 levels.
DATA EXTRACTION AND SYNTHESIS
We collected individual participant data on 47 573 adults (3451 subclinical hypothyroidism) from 17 cohorts and followed up from 1972-2014 (489 192 person-years). Age- and sex-adjusted pooled hazard ratios (HRs) for participants with subclinical hypothyroidism compared to euthyroidism were 1.05 (95% confidence interval [CI], 0.91-1.21) for stroke events (combined fatal and nonfatal stroke) and 1.07 (95% CI, 0.80-1.42) for fatal stroke. Stratified by age, the HR for stroke events was 3.32 (95% CI, 1.25-8.80) for individuals aged 18-49 years. There was an increased risk of fatal stroke in the age groups 18-49 and 50-64 years, with a HR of 4.22 (95% CI, 1.08-16.55) and 2.86 (95% CI, 1.31-6.26), respectively (p trend 0.04). We found no increased risk for those 65-79 years old (HR, 1.00; 95% CI, 0.86-1.18) or ≥ 80 years old (HR, 1.31; 95% CI, 0.79-2.18). There was a pattern of increased risk of fatal stroke with higher TSH concentrations.
CONCLUSIONS
Although no overall effect of subclinical hypothyroidism on stroke could be demonstrated, an increased risk in subjects younger than 65 years and those with higher TSH concentrations was observed.
Topics: Adult; Asymptomatic Diseases; Female; Humans; Hypothyroidism; Incidence; Male; Risk Factors; Stroke; Thyrotropin
PubMed: 25856213
DOI: 10.1210/jc.2015-1438 -
Frontiers in Endocrinology 2022Clinical hypothyroidism is defined by the inadequate production of thyroid hormone from the thyroid gland to maintain normal organ system functions. For nearly all... (Review)
Review
Clinical hypothyroidism is defined by the inadequate production of thyroid hormone from the thyroid gland to maintain normal organ system functions. For nearly all patients with clinical hypothyroidism, lifelong treatment with thyroid hormone replacement is required. The primary goal of treatment is to provide the appropriate daily dose of thyroid hormone to restore normal thyroid function for each individual patient. In current clinical practice, normalization of thyrotropin (TSH) level is the primary measure of effectiveness of treatment, however the use of a single biomarker to define adequate thyroid hormone replacement is being reevaluated. The assessment of clinical health outcomes and patient-reported outcomes (PROs), often within the context of intensity of treatment as defined by thyroid function tests (i.e., undertreatment, appropriate treatment, or overtreatment), may play a role in evaluating the effectiveness of treatment. The purpose of this narrative review is to summarize the prominent health outcomes literature in patients with treated hypothyroidism. To date, overall mortality, cardiovascular morbidity and mortality, bone health and cognitive function have been evaluated as endpoints in clinical outcomes studies in patients with treated hypothyroidism. More recent investigations have sought to establish the relationships between these end results and thyroid function during the treatment course. In addition to clinical event outcomes, patient-reported quality of life (QoL) has also been considered in the assessment of adequacy of hypothyroidism treatment. From a health care quality perspective, treatment of hypothyroidism should be evaluated not just on its effectiveness for the individual patients but also to the extent to which patients of different sociodemographic groups are treated equally. Ultimately, more research is needed to explore differences in health outcomes between different sociodemographic groups with hypothyroidism. Future prospective studies of treated hypothyroidism that integrate biochemical testing, PROs, and end result clinical outcomes could provide a more complete picture into the effectiveness of treatment of hypothyroidism.
Topics: Humans; Thyroxine; Quality of Life; Prospective Studies; Hypothyroidism; Thyroid Hormones; Treatment Outcome
PubMed: 36329885
DOI: 10.3389/fendo.2022.1026262 -
Indian Pediatrics Nov 2014Subclinical hypothyroidism is a biochemical diagnosis characterized by raised thyroid stimulating hormone and normal free T4, without clinical features of... (Review)
Review
NEED AND PURPOSE OF REVIEW
Subclinical hypothyroidism is a biochemical diagnosis characterized by raised thyroid stimulating hormone and normal free T4, without clinical features of hypothyroidism. This review analyzes the current evidence to arrive at a consensus and algorithm to manage this condition.
METHODS
We searched Pubmed, Cochrane and Embase for articles published between 1990 to 2014, and identified 13 relevant articles dealing with pediatric subclinical hypothyroidism which were suitable to include in our review.
CONCLUSIONS
Subclinical hypothyroidism is often a benign problem which requires expectant management with periodic monitoring of thyroid function tests and natural progression to overt hypothyroidism occur lot less frequently than expected. There is a paucity of robust randomized intervention studies, especially studies focusing on clinical outcomes. Thyroid replacement therapy is not justified in children with subclinical hypothyroidism when Thyroid stimulating hormone is <10 mIU/L. The main risk factors for progression to overt hypothyroidism are female sex, goiter, family history of thyroid disorder, strongly positive thyroid peroxidase antibodies and symptoms suggesting hypothyroidism. An algorithm for managing this condition is suggested.
Topics: Female; Goiter; Humans; Hypothyroidism; Male; Thyroid Function Tests; Thyrotropin; Thyroxine
PubMed: 25432218
DOI: 10.1007/s13312-014-0522-9 -
Frontiers in Endocrinology 2023Hysterosalpingography (HSG) using oil-soluble contrast medium (OSCM) improves pregnancy rates but results in severe and persistent iodine excess, potentially impacting... (Clinical Trial)
Clinical Trial
CONTEXT
Hysterosalpingography (HSG) using oil-soluble contrast medium (OSCM) improves pregnancy rates but results in severe and persistent iodine excess, potentially impacting the fetus and neonate.
OBJECTIVE
To determine the incidence of thyroid dysfunction in newborns conceived within six months of OSCM HSG.
DESIGN
Offspring study of a prospective cohort of women who underwent OSCM HSG.
SETTING
Auckland region, New Zealand (2020-2022).
PARTICIPANTS
Offspring from the SELFI (Safety and Efficacy of Lipiodol in Fertility Investigations) study cohort (n=57).
MEASUREMENTS
All newborns had a dried blood spot card for TSH measurement 48 hours after birth as part of New Zealand's Newborn Metabolic Screening Programme. Forty-one neonates also had a heel prick serum sample at one week to measure thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3). Maternal urine iodine concentration (UIC) and TSH in the six months after OSCM HSG were retrieved from the SELFI study for analyses.
PRIMARY OUTCOME
Incidence of hypothyroidism in the neonatal period.
RESULTS
There was no evidence of primary hypothyroidism on newborn screening (TSH 2-10 mIU/L). All neonates tested at one week had normal serum TSH, FT4, and FT3 levels. However, increasing maternal peak UIC levels during pregnancy were associated with lower TSH levels (p= 0.006), although also associated with lower FT4 levels (p=0.032).
CONCLUSIONS
While pre-conceptional OSCM HSG in women did not result in neonatal hypothyroidism, gestational iodine excess was associated with a paradoxical lowering of neonatal TSH levels despite lower FT4 levels. These changes likely reflect alterations in deiodinase activity in the fetal hypothalamic-pituitary axis from iodine excess.
TRIAL REGISTRATION
https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12620000738921, identifier 12620000738921.
Topics: Female; Humans; Infant, Newborn; Pregnancy; Contrast Media; Hypothyroidism; Iodine; Prospective Studies; Thyrotropin; Thyroxine
PubMed: 36798662
DOI: 10.3389/fendo.2023.1080330 -
Frontiers in Endocrinology 2023Previous observational studies have reported a positive correlation between obesity and susceptibility to hypothyroidism; however, there is limited evidence from...
INTRODUCTION
Previous observational studies have reported a positive correlation between obesity and susceptibility to hypothyroidism; however, there is limited evidence from alternative methodologies to establish a causal link.
METHODS
We investigated the causal relationship between obesity and hypothyroidism using a two-sample bidirectional Mendelian randomization (MR) analysis. Single-nucleotide polymorphisms (SNPs) associated with obesity-related traits were extracted from a published genome-wide association study (GWAS) of European individuals. Summarized diagnostic data of hypothyroidism were obtained from the UK Biobank. Primary analyses were conducted using the inverse variance-weighted (IVW) method with a random-effects model as well as three complementary approaches. Sensitivity analyses were performed to ascertain the correlation between obesity and hypothyroidism.
RESULTS
MR analyses of the IVW method and the analyses of hypothyroidism/myxedema indicated that body mass index (BMI) and waist circumference (WC) were significantly associated with higher odds and risk of hypothyroidism. Reverse MR analysis demonstrated that a genetic predisposition to hypothyroidism was associated with an increased risk of elevated BMI and WC, which was not observed between WC adjusted for BMI (WCadjBMI) and hypothyroidism.
DISCUSSION
Our current study indicates that obesity is a risk factor for hypothyroidism, suggesting that individuals with higher BMI/WC have an increased risk of developing hypothyroidism and indicating the importance of weight loss in reducing the risk of hypothyroidism.
Topics: Humans; Genome-Wide Association Study; Mendelian Randomization Analysis; Hypothyroidism; Causality; Obesity
PubMed: 38260160
DOI: 10.3389/fendo.2023.1287463 -
Frontiers in Immunology 2023Hypothyroidism and hyperthyroidism are observationally associated with rheumatoid arthritis (RA), but causality is unclear. To evaluate the causal relationship between...
BACKGROUND
Hypothyroidism and hyperthyroidism are observationally associated with rheumatoid arthritis (RA), but causality is unclear. To evaluate the causal relationship between thyroid function and RA, we conducted a two-Sample bidirectional Mendelian Randomization (MR) study.
METHODS
Single nucleotide polymorphisms associated with six phenotypes were selected from the FinnGen biobank database, The ThyroidOmics Consortium database, and the IEU Open GWAS database. For the forward MR analysis, we selected hypothyroidism (N=213,390), Graves' disease (GD) (N=199,034), other types of hyperthyroidism (N=190,799), free thyroxine (FT4, N=49,269), and thyroid-stimulating hormone (TSH, N=54,288) as the five related thyroid function phenotypes for exposure, with RA (N=58,284) as the outcome. Reverse MR analysis selected RA as the exposure and five phenotypes of thyroid function as the outcome. The Inverse variance weighting (IVW) method was used as the primary analysis method, supplemented by weighted median (WM) and MR-Egger methods. Cochran's Q test, MR-PRESSO, MR-Egger regression methods, and leave-one-out analysis were employed to assess sensitivity and pleiotropy.
RESULTS
Forward MR evidence indicates that genetic susceptibility to hypothyroidism is associated with an increased risk of RA (OR=1.758, P=7.61×10). Reverse MR evidence suggests that genetic susceptibility to RA is associated with an increased risk of hypothyroidism (OR=1.274, P=3.88×10), GD (OR=1.269, P=8.15×10), and other types of hyperthyroidism (OR=1.141, P=1.80×10). There is no evidence to support a forward or reverse causal relationship between genetic susceptibility to RA and FT4, TSH.
CONCLUSION
Our results provide genetic evidence supporting bidirectional causal relationships between thyroid function and RA. These findings inform preventive strategies and interventions targeting RA and thyroid dysfunction.
Topics: Humans; Mendelian Randomization Analysis; Hyperthyroidism; Hypothyroidism; Arthritis, Rheumatoid; Graves Disease; Genetic Predisposition to Disease; Thyrotropin
PubMed: 38090574
DOI: 10.3389/fimmu.2023.1238757 -
Endocrine Jan 2021The incidence of primary congenital hypothyroidism (CH) has grown progressively and literature data indicate an association between CH and congenital malformations. The...
PURPOSE
The incidence of primary congenital hypothyroidism (CH) has grown progressively and literature data indicate an association between CH and congenital malformations. The purpose of this study is to establish the current incidence of CH in the Italian Region of Piedmont and verify the relationship between CH diagnostic categories and associated malformations.
METHODS
The biochemical and clinical data of 105 newborns with CH diagnosed in the period January 2014 to December 2019 were analyzed.
RESULTS
The incidence of CH in the Italian Piedmont region in the 2014-2019 period increased to 1:1090. Thyroid dysgenesis was responsible for 47.6% (50/105) of all cases, with agenesis in 14.3% (15/105), while ectopia and hypoplasia in 23.8% (25/105) and 9.5% (10/105) of the cases, respectively; dyshormonogenesis defects were found in 52.4% (55/105) of cases. Congenital extra-thyroid anomalies were identified in 33/105 (31.4%) of newborns with CH and mainly involve the cardiac system (17/85, 16.1%), urogenital tract (7/85, 6.7%), gastrointestinal tract (5/105, 4.8%), and the musculoskeletal system (5/105, 4.8%). The highest rate of malformations was observed in patients with thyroid agenesis and dyshormonogenesis, respectively, in 53.5% and 36.4% of cases, while in the presence of thyroid ectopia and hypoplasia, the rate was 12% and 20%, respectively, (p = 0.03).
CONCLUSION
In the Italian region of Piedmont, the incidence of primary CH has been increased over time, with a variation in the percentage of the different forms of CH. Congenital malformations, especially affecting the cardiovascular, urogenital, gastrointestinal, and musculoskeletal systems, seem to be mainly associated with thyroid agenesis or defects in hormonogenesis.
Topics: Congenital Hypothyroidism; Humans; Incidence; Infant, Newborn; Italy; Neonatal Screening; Thyroid Dysgenesis
PubMed: 32507964
DOI: 10.1007/s12020-020-02370-w -
Advances in Therapy Jul 2020Hypothyroidism is one of the most common chronic endocrine conditions. However, as symptoms of hypothyroidism are non-specific, up to 60% of those with thyroid... (Review)
Review
Hypothyroidism is one of the most common chronic endocrine conditions. However, as symptoms of hypothyroidism are non-specific, up to 60% of those with thyroid dysfunction are unaware of their condition. Left untreated, hypothyroidism may contribute to other chronic health conditions. In the Arabian Gulf States, hypothyroidism is thought to be common, but is underdiagnosed, and management approaches vary. An advisory board of leading Saudi endocrinologists and policy advisers was convened to discuss and formulate recommendations for the diagnosis and management of hypothyroidism in Saudi Arabia based on their clinical expertise. The final document was shared with leading endocrinologists from the other Gulf Cooperation Council (GCC) and aconsensus report was generated and summerized in this article. While there is no consensus regarding population screening of hypothyroidism, current recommendations suggest screening patients with risk factors, including those with a history of head or neck irradiation, a family history of thyroid disease or pharmacological treatment that may affect thyroid function. Evidence from a cross-sectional study in Saudi Arabia suggests screening the elderly (> 60 years), at least in the primary care setting. In Saudi Arabia, the incidence of congenital hypothyroidism is approximately 1 in every 3450 newborns. Saudi nationwide population prevalence data are lacking, but a single-centre study estimated that the prevalence of subclinical hypothyroidism in the primary care setting was 10%. Prevalence rates were higher in other cross-sectional studies exclusively in women (13-35%). The recommendations included in this article aim to streamline the diagnosis and clinical management of hypothyroidism in the GCC, especially in the primary care setting, with the intention of improving treatment outcomes. Further study on the incidence, prevalence and risk factors for, and clinical features of, hypothyroidism in the GCC countries is required.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Cross-Sectional Studies; Diagnostic Techniques and Procedures; Female; Humans; Hypothyroidism; Incidence; Infant; Infant, Newborn; Male; Middle Aged; Practice Guidelines as Topic; Prevalence; Saudi Arabia; Symptom Assessment; Thyroxine; Young Adult
PubMed: 32488658
DOI: 10.1007/s12325-020-01382-2