Active clinical trials for "Hypothyroidism"

This study is designed to test the hypothesis that the level of the thyroid hormone thyroxine (specifically, free thyroxine, FT4) circulating in the blood of pregnant women is the key thyroid-related factor to influence early fetal brain development. The investigators will recruit 5000 pregnant women with clinically normal thyroid function (normal thyroid stimulating hormone levels) in the second trimester. After the baby has been born, the investigators will measure FT4 in the second trimester maternal blood sample to identify 100 cases (very low FT4 levels) and 100 matched controls (normal FT4 levels). The children of cases and controls will undergo neurodevelopmental testing at 2 years of age to determine whether IQ differs according to maternal FT4 levels during pregnancy. The potential impact of the study is that if such an effect is found, it might be possible to avoid these adverse developmental consequences in children by designing and testing strategies to identify and treat high risk women.

Low RAIU in patients with hyperthyroidism represents a common obstacle in the treatment with RAI. Therefore, a higher dose of RAI must be administered to cure hyperthyroidism in these patients. If we treat patients with thiamazole before starting RAI treatment, serum TSH will rise and result in an increase in iodine uptake by the thyroid gland. By doing so, the dose of RAI to be administered might be lowered to achieve similar therapeutic efficacy. In the past, either calculated or fixed doses of 131I have been used to treat hyperthyroidism. The supposed advantage of a calculated dose compared to a fixed dose is the lowering of hypothyroidism frequency. However, various research papers have contradicted this statement. Antithyroid drugs and RAI therapy have been widely used in the past, either in combination, or independent from one another. This has been done primarily in older patients, to reduce the risk of exacerbation of hyperthyroid symptoms after initiation of RAI. The use of propylthiouracil has been shown to decrease the response rate after RAI due to radioprotective effects. The use of methimazole and carbimazole did not have a negative effect on treatment failure, as long as the medication was discontinued various days before RAI administration. Although this statement is contested in other studies. It is interesting to evaluate retrospective data of patients treated with RAI to evaluate prognostic factors of treatment respons and post RAI hypothyroidism.

Non invasive methods: maternal antithyroid antibodies and ultrasound measurement of the fetal thyroid gland could be an important tool for detecting fetal thyroid dysfunction in mothers with autoimmune thyroid disease.

Iodine is an essential component of thyroid hormone, which is necessary for many metabolic processes as well as the maturation of the CNS. Deficiencies of iodine have deleterious effects on both pregnant women and infants. The iodine status of the population after implementation of the universal salt iodization program in Zhejiang province has not been known. This study was to determine whether pregnant women show evidence of iodine deficiency, and to examine the correlation between maternal urine iodine concentration and newborn thyroid function.

The study tries to determine if post partum thyroiditis has marked long term (20 years after partum) risk for developing hypothyroidism.

Congenital hypothyroidism (CH) occurs in 1:4000 live births. Neurological disturbances like speech delay, motor delay and lower IQ were reported in children with CH. Evidence from animal experiments indicate that CH is associated with high frequency of deafness. Morphological changes of the external and internal cholera hairs were reported in mutagenic mice with CH. Anatomical changes of the internal ear and low hearing threshold were reported in mice bearing Dual oxidase 2 (Duox2) gene mutations, which is responsible of oxidation of iodide. Knockout of Pax8 gene in mice resulted in both agenesis of thyroid gland and deafness. Early L-thyroxin therapy prevented the development of deafness in those mice. The expression of thyroid receptor α (TRα) in the external and internal cholera hairs in mice indicates that the thyroid hormones have an important role in the development of the internal ear. The etiology of deafness in human is both genetic and environmental. The prevalence of deafness in live births is 1:1000 and among them 60% is genetic. Connexin 26 gene mutations are the most common cause of inherited deafness and account for about 40% of the genetic cases. In two conditions in human the coexistence of hypothyroidism and deafness were reported; Pendred syndrome and thyroid hormone resistance syndrome. The prevalence of hearing loss in human with CH was explored in only few studies and the results are contrary. The aim of the current study is to study the prevalence of hearing loss among children with CH and to compare the clinical, biochemical and genetic characteristics between subjects with hearing loss to those without hearing loss.

Congenital hypothyroidism is one of the most preventable causes of neurocognitive impairment because early treatment is possible in neonates. The thyroid hormone is important for normal growth and development in infancy. After introducing national screening test using capillary thyroid stimulating hormone level, the incidence of untreated congenital hypothyroidism has significantly decreased. According to the Italian Registry of Congenital Hypothyroidism, congenital heart disease is the most frequent disease condition associated with congenital hypothyroidism. Congenital heart disease is also reported to be a risk factor for non-autoimmune hypothyroidism in children. In addition, intravenous iodine contrast media is frequently used for diagnostic imaging and therapeutic intervention in congenital heart disease patients. Excess iodine exposed by iodine contrast media may disturb thyroid function in adult and pediatric population. However, there is no generally accepted guideline for screening thyroid dysfunction in congenital heart disease infants. An increased prevalence of thyroid disease, particularly sub-clinical hypothyroidism, has been reported in Down Syndrome. In children with Down Syndrome, a possible concomitant sub-clinical hypothyroidism-related impairment of cardiac function or structure may worsen their clinical condition and can ultimately affect their life expectancy.

Worldwide Data suggest that Iodine deficiency is a concern among healthy pregnant women. Thus, screening first trimester healthy pregnant women for iodine status is of clinical value for mother and child as iodine deficiency might have implications on thyroid function as well as pregnancy outcomes

Diabetes Mellitus is the most common disorder seen. The impact of this disease on the quality of life, and on morbidity and mortality through the complications that affect the small and large vessels resulting in retinopathy, nephropathy, neuropathy, and ischemic heart disease has been emphasized by the findings of the national commission (USA) on diabetes . So, there was curiosity to understand and learn the association of this disorder with another common endocrine gland function that is thyroid gland . The association between these two disorders has long been recognized although the prevalence of thyroid dysfunction in diabetic population varies widely between studies. With insulin and thyroid hormone being intimately involved in cellular metabolism and thus excess or deficit of these hormones result in functional derangement of the other.

Physiological changes necessitate the use of pregnancy-specific reference ranges for TSH and FT4 to diagnose thyroid dysfunction during pregnancy. Although many centers use fixed upper limits for TSH of 2.5 or 3.0 mU/L, this may lead to overdiagnosis or even overtreatment. The new guidelines of the American Thyroid Association have considerably changed recommendations regarding thyroid function reference ranges in pregnancy accordingly. Any hospital or physician that is still using the 2.5 or 3.0 mU/l cut-off for TSH during pregnancy should evaluate their own lab-specific cut-offs. The investigator's objective is to establish a rational reference range of serum TSH for diagnosis of subclinical hypothyroidism in the first and second trimester of pregnant women in west Black Sea region in Turkey.