scholarly journals Understanding the Pathogenesis of Gestational Hypothyroidism

2021 ◽  
Vol 12 ◽  
Author(s):  
Oshini Mallawa Kankanamalage ◽  
Qiongjie Zhou ◽  
Xiaotian Li
Keyword(s):  
Thyroid Function ◽  
Fetal Loss ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Premature Delivery ◽  
Overt Hypothyroidism ◽  
Thyroglobulin Level ◽  
Vulnerable Individual ◽  
Levothyroxine Treatment ◽  
Free Thyroxine Level

Pregnancy is a complex state with many endocrinological challenges to a woman’s physiology. Gestational Hypothyroidism (GHT) is an emerging condition where insufficiency of the thyroid gland has developed during pregnancy in a previously euthyroid woman. It is different to overt hypothyroidism, where marked elevation of thyroid-stimulating hormone with corresponding reduction in free thyroxine levels, is well known to cause detrimental effects to both the mother and the baby. During the past couple of decades, it has been shown that GHT is associated with multiple adverse maternal and fetal outcomes such as miscarriage, pre-eclampsia, placental abruption, fetal loss, premature delivery, neurocognitive and neurobehavioral development. However, three randomized controlled trials and a prospective cohort study performed within the last decade, show that there is no neurodevelopmental improvement in the offspring of mothers who received levothyroxine treatment for GHT. Thus, the benefit of initiating treatment for GHT is highly debated within the clinical community as there may also be risks associated with over-treatment. In addition, regulatory mechanisms that could possibly lead to GHT during pregnancy are not well elucidated. This review aims to unravel pregnancy induced physiological challenges that could provide basis for the development of GHT. During pregnancy, there is increased renal clearance of iodine leading to low iodine state. Also, an elevated estrogen level leading to an increase in circulating thyroglobulin level and a decrease in free thyroxine level. Moreover, placenta secretes compounds such as human chorionic gonadotropin (hCG), placental growth factor (PIGF) and soluble FMS-like tyrosine kinase-1 (s-Flt1) that could affect the thyroid function. In turn, the passage of thyroid hormones and iodine to the fetus is highly regulated within the placental barrier. Together, these mechanisms are hypothesized to contribute to the development of intolerance of thyroid function leading to GHT in a vulnerable individual.

scholarly journals Association between ultrasonography echogenicity and heterogeneity and thyroid function in autoimmune diffuse thyroid diseases in children and adolescents 

2021 ◽  
Author(s):  
Ji Eun Park ◽  
Sook Min Hwang ◽  
Ji-Young Hwang ◽  
Jin Hee Moon ◽  
Ik Yang ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Thyroid Dysfunction ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Diseases ◽  
Overt Hypothyroidism ◽  
Thyroid Ultrasound ◽  
Thyroid Status ◽  
Children And Adolescent ◽  
Overt Hyperthyroidism

Abstract Purpose: To evaluate the association between thyroid echogenicity and heterogeneity seen on ultrasonography (US) and thyroid function in pediatric and adolescent populations with autoimmune diffuse thyroid diseases (AITD).Methods: From 2000 to 2020, we reviewed thyroid ultrasound (US) images and thyroid function statuses in 133 children and adolescent AITD patients. Our review of the images focused on decreased echogenicity and heterogeneity, which were classified into four grades.Results: Among patients with overt hypothyroidism or overt hyperthyroidism, 94.2% (65/69) showed a US grade of 3 or 4. In patients with subclinical hyper/hypothyroidism or euthyroidism, 45.3% (29/64) showed grades 1 or 2. There were no overt hyper/hypothyroidism patients with US grade 1. When we compared US grades according to thyroid status, more severe thyroid dysfunction was significantly associated with higher US grade (p=0.047). Thyroid stimulating hormone (TSH) level differed significantly according to US grades when we evaluated hyperthyroid (p=0.035) and hypothyroid (p=0.027) states independently. 11 patients showed both US grade and thyroid function status changes on follow-up US.Conclusions: In children and adolescent AITD patients, there was an association between decreased echogenicity and heterogeneity on US and thyroid dysfunction.

scholarly journals Status of Thyroid Function among Patients of National Medical College and Teaching Hospital

Med Phoenix ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 64-70
Author(s):  
Anup Shamsher Budhathoki ◽  
Suprita Gupta ◽  
Sanjay Kumar Sah ◽  
Navin Kumar Sah ◽  
Navin Kumar Sah ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Teaching Hospital ◽  
Thyroid Dysfunction ◽  
Thyroid Stimulating Hormone ◽  
Overt Hypothyroidism ◽  
Central Laboratory ◽  
National Medical College ◽  
Medical College ◽  
National Medical ◽  
High Prevalence

Background: Thyroid dysfunction is one of the most common endocrinopathies after Diabetes Mellitus. Thyroid dysfunction is defined as the alteration in Thyroid Stimulating Hormone (TSH) with normal or abnormal thyroid hormones. Nepalese population have a high risk for thyroid dysfunction with a high prevalence of iodine deficiency. Objective: To study the prevalence of thyroid dysfunction among the patients visiting National Medical College, Birgunj, Nepal for checkup and suggested to assess thyroid function. Materials and Methods: The hospital-based study was conducted in Central Laboratory, National Medical College and Teaching Hospital (NMCTH), Birgunj in collaboration with the Department of Biochemistry. Total 7040 patients visiting Central Laboratory for thyroid function assessment were included in the study between July 2017 to December 2019. The venous blood sample was collected and serum-free triiodothyronine(fT3), free tetraiodothyronine(fT4) and thyroid stimulating hormone (TSH) was estimated by Chemiluminescence Immunoassay (CLIA) method using Access 2 Beckman Coulter analyser. (Beckman Coulter Inc., California, USA). Results: Among 7040 subjects under study, 2138(30%) were found to have thyroid dysfunction with 13% having subclinical hypothyroidism, about 8% of overt hypothyroidism, about 4% with subclinical hyperthyroidism and 5% with overt hyperthyroidism. Majority of the thyroid dysfunction study group belonged to the 16-30 years age group followed by 31-45 years. Mean±SE for TSH, fT4 and fT3 levels show statistically significant differences in different thyroid disorders. Conclusion: The study revealed a high prevalence of subclinical hypothyroidism followed by overt hypothyroidism among the patients visiting National Medical College and Teaching Hospital, Birgunj, Nepal. A higher percentage of females were found to have thyroid dysfunction compared to male.

Subclinical hypothyroidism

2011 ◽  
pp. 543-547
Author(s):  
Jayne A. Franklyn
Keyword(s):  
Thyroid Function ◽  
Subclinical Hypothyroidism ◽  
Expert Panel ◽  
Elevated Serum ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Free Triiodothyronine ◽  
Function Tests ◽  
Serum Tsh

Subclinical hypothyroidism is defined biochemically as the association of a raised serum thyroid-stimulating hormone (TSH) concentration with normal circulating concentrations of free thyroxine (T4) and free triiodothyronine (T3). The term subclinical hypothyroidism implies that patients should be asymptomatic, although symptoms are difficult to assess, especially in patients in whom thyroid function tests have been checked because of nonspecific complaints such as tiredness. An expert panel has recently classified individuals with subclinical hypothyroidism into two groups (1): (1) those with mildly elevated serum TSH (typically TSH in the range 4.5–10.0 mU/l) and (2) those with more marked TSH elevation (serum TSH >10.0 mU/l).

scholarly journals Thyroid dysfunction in preeclampsia and related fetomaternal outcomes

2019 ◽  
Vol 8 (5) ◽  
pp. 1928
Author(s):  
Puja Banik ◽  
R. K. Praneshwari Devi ◽  
Aheibam Bidya ◽  
Akoijam Tamphasana ◽  
M. Agalya ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Thyroid Dysfunction ◽  
Birth Asphyxia ◽  
Normal Pregnancy ◽  
Thyroid Stimulating Hormone ◽  
Severe Preeclampsia ◽  
Intrauterine Fetal Death ◽  
Overt Hypothyroidism ◽  
Thyroid Function Tests ◽  
Cross Sectional

Background: Changes in thyroid function in normal pregnancy are well-documented but in complicated pregnancy like preeclampsia, very little is known. Studies have shown evidences of hypothyroidism in preeclampsia necessitating thyroid function tests to be done in preeclampsia. The study was done to analyze the fetomaternal outcome of preeclampsia with coexisting thyroid dysfunction.Methods: A cross-sectional analytical study was done over 18 months on 95 preeclamptic patients admitted at the antenatal ward and fetomaternal outcomes were analyzed according to thyroid status.Results: Out of 95 patients with preeclampsia, 42 (44.2%) had thyroid dysfunction. Among these 42 patients, 37 (38.9%) patients had subclinical hypothyroidism, 4 (4.2%) had overt hypothyroidism and 1 (1%) had hyperthyroidism. Severe preeclampsia was seen in 64.3% of the patients with thyroid dysfunction compared with 39.6% in euthyroid patients. The mean thyroid stimulating hormone (TSH) level was significantly higher and means free thyroxine (fT4) level was significantly lower in severe preeclampsia compared with non-severe preeclampsia. Complications like abruption, intrauterine fetal death (IUD), intrauterine growth restriction (IUGR), oligohydramnios, preterm deliveries, postpartum hemorrhage (PPH), low birth weight babies, birth asphyxia in babies and subsequent neonatal intensive care unit (NICU) admissions were significantly higher (p <0.05) in the preeclampsia patients with thyroid dysfunction in comparison with euthyroid ones.Conclusions: Hypothyroidism may be a modifiable risk factor for preeclampsia. Thyroid screening early in pregnancy may be helpful in predicting the occurrence of preeclampsia and timely thyroid hormone administration can reduce the maternal and perinatal morbidity and mortality associated with preeclampsia.

Hypothyroidism following Treatment for Head and Neck Cancer

1981 ◽  
Vol 90 (5) ◽  
pp. 449-453 ◽  
Author(s):  
Donald P. Vrabec ◽  
Timothy J. Heffron
Keyword(s):  
Radiation Therapy ◽  
Head And Neck ◽  
Thyroid Function ◽  
Elevated Serum ◽  
Thyroid Stimulating Hormone ◽  
Primary Hypothyroidism ◽  
Overt Hypothyroidism ◽  
Patient Will ◽  
Effects Of Radiation ◽  
Tsh Levels

One hundred ninety-six head and neck patients were studied to determine the effects of radiation therapy and surgery on thyroid function. Serum thyroid-stimulating hormone (TSH) levels were obtained as a screening test for primary hypothyroidism. Elevated TSH levels were found in 57 of the 196 patients (29.1%). The highest incidence of abnormal TSH values (66%) occurred in the group treated with combination radiation therapy and surgery, including partial thyroidectomy. TSH levels rose early in the posttreatment period with 60% of the abnormal values occurring within the first three posttreatment years. Posttreatment thyroid dysfunction was twice as common in women (48.6%) as in men (25.4%). When serum thyroxine levels by radioimmunoassay (T4RIA) were correlated with the elevated serum TSH levels, a similar pattern was seen with 65% of the patients in Group 3 having a decreased T4RIA level indicating overt hypothyroidism. Pretreatment levels of thyroid function including thyroid antibody studies should be established for all patients. Serial TSH levels should be done every three months during the first three posttreatment years and semiannually thereafter as long as the patient will return for follow-up care. All patients treated with combination radiation therapy and surgery who develop elevated TSH levels should be treated with thyroid replacement therapy. Patients receiving radiation therapy alone should receive replacement thyroid therapy if they develop a depressed T4RIA value or a pattern of gradually increasing TSH levels.

scholarly journals Obesity and hypothyroidism

2013 ◽  
Vol 10 (2) ◽  
pp. 54-58 ◽  
Author(s):  
S M Zakharova ◽  
L V Savelieva ◽  
M I Fadeeva
Keyword(s):  
Weight Loss ◽  
Energy Expenditure ◽  
Thyroid Function ◽  
Thyroid Dysfunction ◽  
Thyroid Stimulating Hormone ◽  
Overt Hypothyroidism ◽  
Obese Patients ◽  
Common Diseases ◽  
The Relationship ◽  
Stimulating Hormone

Obesity and hypothyroidism are common diseases, and consequently clinicians should be particularly alert to the possibility of thyroid dysfunction in obese patients. The relationship between thyroid function and obesity is likely to be bidirectional, with hypothyroidism affecting weight, but obesity also influencing thyroid function. Both serum thyroid-stimulating hormone and fT3 are typically increased in obese individuals, an effect likely mediated by leptin. Following L-T4 treatment for overt hypothyroidism, weight loss appears to be modest and mediated primarily by loss of water weight rather than fat. Selected thyroid analogs might be a means by which to improve weight loss by increasing energy expenditure in obese patients during continued caloric deprivation

Thyroid evaluation of children and adolescents with Williams syndrome in Zhejiang Province

2017 ◽  
Vol 30 (12) ◽  
Author(s):  
Wei-Jun Chen ◽  
Chai Ji ◽  
Dan Yao ◽  
Zheng-Yan Zhao
Keyword(s):  
Children And Adolescents ◽  
Thyroid Function ◽  
Williams Syndrome ◽  
Subclinical Hypothyroidism ◽  
Thyroid Stimulating Hormone ◽  
Zhejiang Province ◽  
Overt Hypothyroidism ◽  
Thyroid Peroxidase ◽  
Thyroid Antibodies ◽  
Free Triiodothyronine

AbstractBackground:The objective of the study was to describe the prevalence of abnormal thyroid function and volume in children and adolescents with Williams syndrome (WS) in Zhejiang Province, China.Methods:Thyroid function, including thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and thyroid antibodies (thyroid peroxidase and thyroglobulin) were measured in 83 patients with WS, aged 0.2–16.5 years. Twenty-three patients were followed for an average of 1.7 years (0.4–4.1), and multiple TSH determinations were considered. Thyroid ultrasonography was performed on 49 patients.Results:One patient was diagnosed with overt hypothyroidism, and 23 patients (27%) had subclinical hypothyroidism (SH). Thyroid antibodies were absent in all patients. In five age groups (0–1 years, 1–3 years, 3–6 years, 6–9 years, 9–18 years), the prevalence of patients with subclinical hypothyroidism was 25%, 28.5%, 44.4%, 16.7% and 4.7%, respectively. Through ultrasound examination, 21 patients (42%) were observed to have thyroid hypoplasia (TH), and there were no cases of thyroid haemiagenesis. The incidence rate of TH increased with age, rising from 20% in the youngest group to 66% in the oldest.Conclusions:SH and TH is common in children and adolescents with WS. Yearly evaluation of thyroid must be performed in all patients in this population, regardless of the result of the neonatal screening. Age under 6 years and existing thyroid abnormalities are risk factors for developing SH, and a shorter follow-up interval is needed for screening in these individuals, SH is often self-limiting, and clinicians should be alert to overt hypothyroidism.

scholarly journals Changes in the prevalence of hypothyroidism: the HUNT Study in Norway

2013 ◽  
Vol 169 (5) ◽  
pp. 613-620 ◽  
Author(s):  
Bjørn Olav Åsvold ◽  
Lars J Vatten ◽  
Trine Bjøro
Keyword(s):  
Thyroid Function ◽  
Subclinical Hypothyroidism ◽  
Prevalence Ratio ◽  
Easy Access ◽  
Overt Hypothyroidism ◽  
Population Surveys ◽  
Thyroid Function Testing ◽  
Hunt Study ◽  
Function Testing ◽  
Levothyroxine Treatment

ObjectiveUntreated hypothyroidism is common in iodine-replete areas. Frequent thyroid function testing and use of levothyroxine treatment for subclinical hypothyroidism suggest that the prevalence may have decreased. Therefore, in this study, we examined changes in the prevalence of hypothyroidism in a Norwegian county from 1995–1997 to 2006–2008.DesignPopulation surveys of 33 917 individuals in 1995–1997 and 49 180 individuals in 2006–2008 were carried out.MethodsWe compared the prevalence of untreated overt, untreated subclinical, and treated hypothyroidism between 1995–1997 and 2006–2008.ResultsThe prevalence of untreated overt hypothyroidism among women decreased by 84% from 1995–1997 (0.75%) to 2006–2008 (0.12%) (prevalence ratio (PR) 0.16; 95% CI 0.10–0.26). The corresponding decrease among men was 43% from 0.21 to 0.12% (PR 0.57; 95% CI 0.28–1.16). The prevalence of untreated subclinical hypothyroidism decreased by 64% from 3.0 to 1.1% in women (PR 0.36; 95% CI 0.31–0.42) and decreased by 54% from 2.1 to 1.0% in men (PR 0.46; 95% CI 0.38–0.56). Conversely, the prevalence of treated hypothyroidism among women increased by 60% from 5.0 to 8.0% (PR 1.60, 95% CI 1.50–1.71), and the corresponding prevalence in men doubled from 1.0 to 2.0% (PR 1.96; 95% CI 1.59–2.41). The prevalence of any form of hypothyroidism remained essentially similar at 9% in women and 3% in men.ConclusionsThe prevalence of untreated hypothyroidism in this Norwegian county decreased strongly from 1995–1997 to 2006–2008. The findings suggest that the prevalence of untreated hypothyroidism in populations with easy access to thyroid function testing and levothyroxine treatment may now be low.

scholarly journals Pattern of Thyroid Dysfunction in Women with Menstrual Disorders

2016 ◽  
Vol 2 (1) ◽  
pp. 3-6
Author(s):  
Saroj Khatiwada ◽  
Sharad Gautam ◽  
Rajendra KC ◽  
Shruti Singh ◽  
Shrijana Shrestha ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Subclinical Hypothyroidism ◽  
Thyroid Dysfunction ◽  
Thyroid Stimulating Hormone ◽  
Overt Hypothyroidism ◽  
Endocrine Disorders ◽  
Thyroid Disorder ◽  
Menstrual Disorders ◽  
Free Triiodothyronine ◽  
Menstrual Disorder

BACKGROUNDThyroid disorders are among the commonest endocrine disorders worldwide. Thyroid dysfunction can interfere in multiple metabolic and physiological processes including menstrual cycle. This study was conducted to find pattern of thyroid dysfunction among women with menstrual disorders.METHODSTwo hundred thirty three females with menstrual disorders were screened for thyroid dysfunction. Thyroid function was assessed by measuring serum free triiodothyronine (T3), free thyroxine (T4) and thyroid stimulating hormone (TSH) levels.RESULTSThe mean age of study patients was 25.7±6.8 years. The most common menstrual disorder observed was irregular cycle (72.5%, n=169) followed by amenorrhea (21.9%, n=51) and menorrhagia (5.6%, n=13). Most of the patients were in the age group 15-24 years (51.1%, n=119), followed by 25-34 years (36.1%, n=84) and 35-45 years (12.9%, n=30). Mean level of free T3 and T4 was 2.91±1.05 pg/ml, 1.42±0.57 ng/dl respectively. Median TSH was 2.0 mIU/L (IQR, 1.0-4.0). Thyroid dysfunction was seen in 25.8% (n=60) women. Most common thyroid dysfunction was subclinical hypothyroidism (14.2%, n=33) followed by subclinical hyperthyroidism (6.9%, n=16), overt hyperthyroidism (3%, n=7) and overt hypothyroidism (1.7%, n=4).CONCLUSIONSThe study finds thyroid dysfunction especially subclinical hypothyroidism to be common among women with menstrual disorders. Thus, it may be beneficial to screen menstrual disorder patients for thyroid function especially to rule out thyroid disorder as potential etiological agent for menstrual disturbance.

scholarly journals Challenges in Interpreting Thyroid Stimulating Hormone Results in the Diagnosis of Thyroid Dysfunction

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Salman Razvi ◽  
Sindeep Bhana ◽  
Sanaa Mrabeti
Keyword(s):  
Thyroid Function ◽  
Thyroid Disease ◽  
Reference Range ◽  
Routine Care ◽  
Time Of Day ◽  
Thyroid Stimulating Hormone ◽  
Overt Hypothyroidism ◽  
Measured Signal ◽  
Pituitary Hormone ◽  
Reference Ranges

The pituitary hormone, thyrotropin (TSH), is regarded as the primary biomarker for evaluating thyroid function and is useful in guiding treatment with levothyroxine for patients with hypothyroidism. The amplified response of TSH to slight changes in thyroid hormone levels provides a large and easily measured signal in the routine care setting. Laboratories provide reference ranges with upper and lower cutoffs for TSH to define normal thyroid function. The upper limit of the range, used to diagnose subclinical (mild) hypothyroidism, is itself a matter for debate, with authoritative guidelines recommending treatment to within the lower half of the range. Concomitant diseases, medications, supplements, age, gender, ethnicity, iodine status, time of day, time of year, autoantibodies, heterophilic antibodies, smoking, and other factors influence the level of TSH, or the performance of current TSH assays. The long-term prognostic implications of small deviations of TSH from the reference range are unclear. Correction of TSH to within the reference range does not always bring thyroid and other biomarkers into range and will not always resolve the patient’s symptoms. Overt hypothyroidism requires intervention with levothyroxine. It remains important that physicians managing a patient with symptoms suggestive of thyroid disease consider all of the patient’s relevant disease, lifestyle, and other factors before intervening on the basis of a marginally raised TSH level alone. Finally, these limitations of TSH testing mitigate against screening the population for the undoubtedly substantial prevalence of undiagnosed thyroid disease, until appropriately designed randomised trials have quantified the benefits and harms from this approach.

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