Search Results (109)

Background/Objectives: The effect of metformin on the secretory function of thyrotropic cells is sex-dependent. The current study aimed to investigate whether the impact of this drug on activity of the hypothalamic–pituitary–thyroid axis in women is impacted by the androgen status of patients. Methods: The study population included 48 levothyroxine-naïve reproductive-aged women with subclinical hypothyroidism and prediabetes receiving 3.0 g of metformin daily. Women with (n = 24) and without (n = 24) polycystic ovary syndrome were matched for age, insulin sensitivity, TSH, and reasons for thyroid hypofunction. Circulating levels of glucose, glycated hemoglobin, insulin, TSH, thyroid hormones, gonadotropins, androgens, estradiol, SHBG, prolactin, ACTH, and IGF-1 were measured before metformin treatment and six months later. Results: At entry, women with and without polycystic ovary syndrome differed in LH, LH/FSH ratio, androgens, and estradiol. The decrease in TSH, fasting glucose and glycated hemoglobin, and the improvement in insulin sensitivity were less pronounced in women with than in women without polycystic ovary syndrome. In each group, there were no differences in the impact on TSH and thyroid hormones between patients with subclinical hypothyroidism of autoimmune and non-autoimmune origin. The changes in TSH inversely correlated with total testosterone and free androgen index. Only in women with coexisting polycystic ovary syndrome, did metformin slightly reduce LH, LH/FSH ratio, testosterone, and free androgen index. Conclusions: The results suggest that concurrent polycystic ovary syndrome attenuates metformin action on TSH secretion, which can be explained by increased androgen production. Moreover, the drug seems to alleviate PCOS-associated changes in the activity of the reproductive axis. Full article

Thyroid hormones play a crucial role in regulating metabolism and cardiovascular function, with even mild dysfunction—such as subclinical hypothyroidism—negatively impacting heart health. While previous studies have confirmed the effects of iodine, selenium, and vitamin D on thyroid regulation and inflammation, the combined role of these nutrients in reducing cardiovascular disease (CVD) risk in autoimmune thyroid disorders remains insufficiently understood. This review explores the influence of specific micronutrients—including selenium, iodine, and zinc—and dietary patterns, particularly the Mediterranean diet, on the pathophysiology of hypothyroidism and Hashimoto’s thyroiditis. We introduce a novel framework that integrates emerging data on sex-specific micronutrient interactions and nutritional immunomodulation. Unlike the existing literature, this review introduces original hypotheses related to sex-specific nutritional immunomodulation and proposes a novel framework for micronutrient-driven dietary intervention in Hashimoto’s thyroiditis. Full article

Background: Psoriasis is a chronic inflammatory skin disease linked to systemic comorbidities, including metabolic, cardiovascular, and autoimmune disorders. Thyroid dysfunction, particularly hypothyroidism, has been observed in patients with moderate-to-severe psoriasis, suggesting possible shared inflammatory pathways. Objectives: This study aims to explore the relationship between psoriasis and thyroid dysfunction in adults with moderate-to-severe psoriasis undergoing biologic therapy to determine whether psoriasis predisposes individuals to thyroid disorders and to identify demographic or clinical factors influencing this association. Materials and Methods: A cross-sectional study included adult patients with moderate-to-severe psoriasis receiving biologic therapy, recruited from the Psoriasis Unit at the Dermatology Department of Hospital Universitario San Cecilio in Granada, Spain, from 2017 to 2023. Patients with mild psoriasis or those treated with conventional systemic therapies were excluded. The data collected included demographics and clinical characteristics, such as age, sex, BMI (body mass index), and psoriasis severity (psoriasis severity was evaluated using the Psoriasis Area Severity Index (PASI), body surface area (BSA) involvement, Investigator’s Global Assessment (IGA), pruritus severity using the Numerical Rating Scale (NRS), and impact on quality of life through the Dermatology Life Quality Index (DLQI)). Thyroid dysfunction, including hypothyroidism and subclinical hypothyroidism, was assessed based on records from the Endocrinology Department. Results: Thyroid dysfunction was found in 4.2% of patients, all classified as hypothyroidism, primarily subclinical. The affected patients were generally older, with a mean age of 57.4 years. No significant differences in psoriasis severity (PASI, BSA) or treatment response were observed between patients with and without thyroid dysfunction. Conclusion: Our findings suggest hypothyroidism is the main thyroid dysfunction in psoriatic patients, independent of psoriasis severity. The lack of impact on psoriasis severity suggests hypothyroidism may be an independent comorbidity, warranting further research into shared inflammatory mechanisms. Full article

Background/Objectives: Hypothyroidism and thyroid autoimmunity have a negative effect on women’s sexual health, which is only partially reversed by thyroid hormone substitution. Sexual functioning in thyroid disorders after delivery has been poorly researched. The aim of our study was to compare the effect of levothyroxine on sexual response and depressive symptoms in women with postpartum thyroiditis (PPT) and different vitamin D status. Methods: The study population consisted of three matched groups of women with the hypothyroid phase of PPT: two groups with subclinical and one with overt thyroid hypofunction. Each group included similar numbers of women with normal and low vitamin D status. For the following six months, one group of women with subclinical hypothyroidism and all women with overt thyroid hypofunction received levothyroxine. At the beginning and at the end of the study, all participants completed questionnaires evaluating female sexual function (FSFI) and depressive symptoms (BMI-II). The remaining outcomes of interest included thyroid antibody titers, and the serum levels of 25-hydroxyvitamin D, TSH, free thyroid hormones, sex hormones, and prolactin. Results: Before levothyroxine substitution, women with overt and subclinical disease differed in the total FSFI score, all domain scores, and the overall BDI-II score. Within each study group, domain scores for desire were greater in women with vitamin D sufficiency than in those with vitamin D deficiency/insufficiency. Testosterone and estradiol levels were lower in women with overt than in women with subclinical hypothyroidism, while the opposite relationship was found for prolactin. Levothyroxine treatment improved all domains of female sexual function and reduced the total BDI-II score in both patients with overt and subclinical hypothyroidism and normal vitamin D status. In women with vitamin D deficiency/insufficiency, the impact of this agent was limited to arousal, lubrication, and sexual satisfaction. Levothyroxine replacement reduced thyroid antibody titers only in women with normal vitamin D status. The impact on testosterone was limited to women with normal vitamin D status, and was more pronounced in women with overt than subclinical disease. The effect on estradiol and prolactin, observed only in overt disease, was unrelated to vitamin D status. The increase in sexual functioning correlated with the following: 25-hydroxyvitamin D levels (in vitamin D-deficient/insufficient women); the impact on thyroid peroxidase antibodies, free triiodothyronine and testosterone (for desire and arousal); and the changes in the overall BDI-II score. Five years later, the quality of life was better in vitamin D-sufficient women receiving levothyroxine in the postpartum period. Conclusions: Low vitamin D status attenuates the impact of levothyroxine on female sexual function and depressive symptoms in women with the hypothyroid phase of PPT. Full article

Hashimoto’s thyroiditis is the most prevalent autoimmune thyroid disorder, and it disproportionately affects women of reproductive age. Its impact on fertility and assisted reproductive technologies [ART] has become an area of growing clinical interest. Thyroid autoimmunity can influence female reproductive health through multiple interconnected mechanisms, including subtle thyroid hormone imbalances, reduced ovarian reserve, altered endometrial receptivity, and dysregulated immune responses. Subclinical hypothyroidism and the presence of anti-thyroid antibodies have been linked to increased miscarriage risk and reduced success rates in ART, particularly in intracytoplasmic sperm injection (ICSI) cycles. Although levothyroxine supplementation is widely used, its benefits in euthyroid women remain uncertain. Recent studies suggest that gut microbiota may modulate immune function and affect fertility outcomes among women with autoimmune thyroid conditions. This narrative review synthesizes findings from a broad literature base of over 40 peer-reviewed publications published between 2010 and 2025, with 30 of the most relevant and methodologically robust studies selected for detailed analysis. The review integrates clinical, endocrine, immunological, and microbiome-related perspectives. The evidence supports the need for personalized fertility management in women with Hashimoto’s thyroiditis and highlights directions for future research into immune and microbiota-targeted therapies. Full article

Background and Clinical Significance: Pituitary apoplexy is an extremely rare condition in children and adolescents with a rapid onset due to acute hemorrhage, infarction, or both in the pituitary gland. Most frequently, pituitary apoplexy is an asymptomatic or subclinical entity. Few cases of pituitary apoplexy with concurrent SARS-CoV-2 infection or COVID-19 vaccination have been reported. Case Presentation: We present the case of a 13-year-8-month-old boy who presented in our pediatric endocrinology department for the evaluation of short stature. He was previously diagnosed with secondary hypothyroidism and was treated with levothyroxine. At admission, clinical examination revealed a height of 141 cm (−2.68 SD/−2.4 SD corrected for mid-parental height), normal weight (60th centile), Tanner-stage G2P1, and delayed bone age. Basal IGF1 was normal, but the tests performed to assess the GH reserve confirmed the GH deficiency (peak GH value 3.11 ng/mL after clonidine/0.95 ng/mL after insulin). The brain MRI revealed a subacute pituitary hemorrhage. Thrombophilia and coagulopathies were excluded by further testing. Anti-SARS-CoV-2 (anti-S-protein IgG) antibodies (>200 BAU/mL) were compatible with COVID-19 infection, indicating a possible association between these two entities. At 3-month follow-up, physical examination showed a 3 cm height gain and advancing pubertal development (G4P2). Newer MRI found changes consistent with resolving hemorrhage. The patient was provided immediately with recombinant human GH and aromatase inhibitor therapy to maximize GH treatment response. During follow-up, the rGH dose was adjusted based on IGF1 values, and after 3 years and 10 months, rGH treatment was stopped, reaching a height of 172.3 cm (−0.51 SD) and surpassing the initial prediction of 164.5 cm. Conclusions: Pituitary apoplexy, an even rarer complication in the pediatric population, may be associated with SARS-CoV-2 infection. Further studies are necessary to better understand the intertwining of those conditions. Full article

Background/Objectives: Metformin inhibits secretory function of overactive thyrotrophs, gonadotrophs, and lactotrophs. The clinical significance of an excess of high-molecular-weight prolactin (macroprolactinemia) remains unclear. The aim of the current study was to investigate for the first time whether macroprolactinemia determines the pituitary effects of this drug. Methods: This single-center prospective case–control study included two groups of postmenopausal women with subclinical hypothyroidism, who were matched for age, insulin sensitivity, and plasma concentrations of gonadotropins and TSH. Group A enrolled women with normal prolactin status, while group B included women with macroprolactinemia. Owing to concomitant type 2 diabetes or prediabetes, all the participants received metformin for six months. The outcomes of interest included glucose homeostasis markers (fasting glucose, glycated hemoglobin, and HOMA-IR), plasma prolactin (total and monomeric), macroprolactin, other pituitary hormones (FSH, LH, TSH, and ACTH), and peripheral hormones (estradiol, free thyroid hormones, and IGF-1). Results: Before metformin treatment, the study groups differed only in concentrations of total prolactin and macroprolactin. Metformin decreased FSH and TSH and tended to decrease LH only in group A, and the strength of this effect showed correlations with the baseline levels of these hormones, the degree of improvement in insulin sensitivity, and the macroprolactin content (only in group B). The decrease in fasting glucose, glycated hemoglobin, and HOMA-IR was more pronounced in group A than group B. There were no differences between the pretreatment and posttreatment values of total prolactin, monomeric prolactin, macroprolactin, ACTH, estradiol, free thyroid hormones, and IGF-1. Conclusions: The obtained results suggest that macroprolactinemia may counteract the pituitary effects of metformin. Full article

Thyroid scintigraphy is a key tool for diagnosing and staging hyperthyroidism in cats, but follow-up scintigraphic studies after radioiodine treatment are limited. This multicentric study evaluated ^99mTc-pertechnetate scintigraphy findings in 234 hyperthyroid cats before and 6 months after radioiodine treatment. Based on serum T4 and TSH concentrations, 165 (70.5%) became euthyroid, 54 (23.1%) had subclinical hypothyroidism, and 15 (6.4%) developed overt hypothyroidism. On post-treatment scintigraphy, all cats showed reduced size and radionuclide uptake of “hot” thyroid nodules. Of 99 cats with unilateral nodules, 60 (61%) recovered function in the contralateral lobe. Among 135 cats with bilateral nodules, both lobes remained visible in 108 (80%). Persistent “hot” nodules with high thyroid/salivary (T/S) ratios or thyroidal pertechnetate uptake (TcTU) occurred in 26 (11%) cats, all of which were euthyroid. Conversely, 24 (10.4%) cats had minimal or absent thyroid tissue with 17 (71%) being hypothyroid, but seven (29%) were euthyroid. As a diagnostic test for iatrogenic hypothyroidism, TcTU showed the highest sensitivity (62.3), with the T/S ratio (7.3) and background-corrected T/S ratio (30.4) being much lower (p < 0.01). While follow-up scintigraphy aids in assessing thyroid tumor destruction and residual function, its diagnostic utility for differentiating euthyroidism and hypothyroidism is limited, especially for cats with mild (subclinical) hypothyroidism. Full article

Background/Objectives: The presence of autoimmune thyroiditis was found to be associated with an increased prevalence of sexual dysfunction. Women’s sexual health was not investigated in postpartum disorders of the thyroid gland. The aim of this study was to assess female sexual functioning and depressive symptoms in postpartum thyroiditis. Methods: This study compared four groups of non-lactating women who gave birth within 12 months before the beginning of the study: women with postpartum thyroiditis and overt hypothyroidism (group A), women with postpartum thyroiditis and subclinical hypothyroidism (group B), euthyroid females with postpartum thyroiditis (group C) and healthy euthyroid females without thyroid disease (group D). All patients completed questionnaires assessing female sexual function (FSFI), and the presence and severity of depressive symptoms (BDI-II). Moreover, we assessed thyroid peroxidase and thyroglobulin antibodies, as well as serum levels of thyroid-stimulating hormone (TSH), free thyroid hormones, testosterone, dehydroepiandrosterone sulfate (DHEAS), estradiol and prolactin. Results: The mean total FSFI score was lower in women with overt hypothyroidism (22.74 ± 4.12) than in the remaining groups of women, lower in groups B (25.71 ± 3.84) and C (29.67 ± 4.00) than in group D (32.15 ± 2.98), as well as lower in group B than in group C. Compared to healthy controls, both groups of women with postpartum thyroiditis and thyroid hypofunction had lower scores for all domains, while euthyroid patients with postpartum thyroiditis had lower scores for sexual desire, sexual arousal and lubrication. The total BDI-II score was highest in group A (15.6 ± 3.2) and lowest in group D (7.8 ± 3.2). Serum testosterone and DHEAS levels were lower while serum prolactin levels were higher in women with postpartum thyroiditis than in healthy subjects. The lowest testosterone levels (1.02 ± 0.35 nmol/L) and estradiol levels (190 ± 80 pmol/L) and the highest prolactin concentration (39.9 ± 13.9 ng/mL) were found in group A. Conclusions: The obtained results show that postpartum thyroiditis is complicated by multidimensional impairment of female sexual functioning, which is accompanied by mood deterioration. Severity of sexual dysfunction and depressive symptoms in this clinical entity depends on the degree of thyroid autoimmunity and hypothyroidism. It seems that assessment of sexual functioning and mood should be recommended to all women with postpartum thyroiditis. Full article

Background: Pregnancy simulates a metabolic syndrome-like state and predisposes to iodine deficiency and hypothyroidism through increased iodine renal loss and transplacental transfer to the fetus. Iodine deficiency is thought to predispose to dyslipidemia through elevation of serum TSH. Obesity, dyslipidemia, and hypothyroidism are established risk factors of preeclampsia. Hence, pregnant women with iodine deficiency are likely to be at increased risk of dyslipidemia and preeclampsia. We investigated the pattern of dyslipidemia among preeclamptic and normotensive pregnant women with and without iodine deficiency. Methods: The pathophysiological mechanisms linking iodine deficiency and dyslipidemia were delineated using bivariate correlations, logistic regression, and exploratory factor analysis of anthropometric, lipid profile, urine iodine concentration (UIC), and thyroid function data from 240 women with preeclampsia and 120 normotensive pregnant controls at term who attended Lomo Medical Centre, Democratic Republic of Congo (DRC). Results: Preeclamptic women with iodine deficiency had significantly lower HDL-C but higher triglyceride levels than those with sufficient iodine intake. Both normotensive and preeclamptic participants with elevated TSH had high serum oxidized LDL-C but low NO, p < 0.001. Conclusions: SCH, secondary to iodine deficiency, is associated with elevated serum oxidized LDL and decreased Nitric Oxide (NO) among both normotensive and preeclamptic women, while insufficient iodine nutrition among preeclamptic women predisposes to reduced HDL-C and increased serum Triglycerides, which are risk factors of atherosclerosis and cardiovascular disease. Full article

Background: Polycystic ovary syndrome (PCOS) and autoimmune thyroid disease (AITD) have a high prevalence in women of reproductive age. PCOS can lead to long-term adverse health effects such as obesity, diabetes, and increased metabolic and cardiovascular risk. Although it is known that subclinical and clinical hypothyroidism may also worsen body mass index (BMI), lipid profile, and metabolic risk, there are few studies on the impact of elevated thyroid autoantibodies alone and associated chronic inflammation on metabolic complications in women with PCOS. The main aim of the study was to assess the prevalence of AITD among Polish women with PCOS and the metabolic impact of the co-occurrence of both diseases in euthyroid individuals. The additional aim was a review of the literature on the prevalence of co-occurrence of PCOS and AITD and the metabolic consequences of this condition. Methods: A total of 424 women aged 16–46 years were recruited into the study—230 women diagnosed with PCOS and 194 women diagnosed with PCOS and co-occurrence of euthyroid AITD. Before participating in the study, patients signed a written informed consent. The study was approved by the local ethics committee. Statistical analysis was performed using IBM SPSS Statistics (v.25). A mini-review of the literature was performed using the PubMed database. Results: Women with co-occurrence of PCOS and euthyroid AITD had statistically significantly higher serum levels of total cholesterol (189.57 mg/dL vs. 180.16 mg/dL; p = 0.005; d Cohen’s = −0.278), LDL-cholesterol (109.80 mg/dL vs. 102.01 mg/dL; p = 0.009; d Cohen’s = −0.256), and triglycerides (107.77 mg/dL vs. 96.82 mg/dL; p = 0.027; d Cohen’s = −0.219) compared to women with PCOS. The difference was observed regardless of body weight. BMI was also statistically significantly higher in the PCOS-AITD group (27.55 kg/m² vs. 25.46 kg/m²; p = 0.003; d Cohen’s = −0.319), as was the prevalence of obesity (32.5% vs. 20.7%; Chi-square = 7.956; p = 0.047). The mini-review of the literature did not find many studies evaluating the impact of thyroid autoantibodies on metabolic outcomes in PCOS euthyroid women, and the data are still inconclusive. Conclusions: The presence of elevated serum concentrations of thyroid autoantibodies in euthyroid women with PCOS increases the risk of obesity and metabolic consequences. It is observed even in euthyroid and non-obese individuals. Consequently, the cardiovascular risk in these women may be higher than in PCOS women without elevated thyroid autoantibodies. It is important to assess thyroid autoantibodies in all women with PCOS. In euthyroid PCOS women with co-occurrence of elevated serum levels of thyroid autoantibodies, it is crucial to pay more attention to maintaining an appropriate body mass index. There is an urgent need for further studies in large groups of women assessing the impact of elevated thyroid autoantibodies alone on metabolic outcomes in euthyroid women with PCOS to confirm and clarify the results. Full article

Background/Objectives: The standard evaluation of children and adolescents suspected of having thyroid disorders consists of anthropometric measurements. Body composition features provide additional information for enhanced therapeutic management. We explored the muscle-to-fat ratio of pediatric patients referred for thyroid disorders and its interaction with thyroid function and metabolic syndrome components. Methods: This retrospective cross-sectional study consisted of 147 pediatric subjects (ages 5–19 years) diagnosed with childhood-onset thyroid disorders treated at a tertiary medical center. Sociodemographic, clinical and laboratory data [thyroid-stimulating hormone (TSH), free T4 (FT4), and lipid profile] were extracted from the electronic medical records. Body composition was measured using bioimpedance analysis (Tanita MC-780 MA and GMON Professional Software). Body mass index (BMI), appendicular muscle mass (ASMM), and muscle-to-fat ratio (MFR) were converted to z-scores. Results: The diagnoses included Hashimoto thyroiditis (30.6%), subclinical hypothyroidism (26.5%), congenital hypothyroidism (21.7%), and Graves’ disease (21%). Based on BMI z-scores, 31.3% of the cohort was overweight or obese. The TSH levels were positively correlated with the BMI z-scores (r = 0.238, p = 0.005) and negatively with the MFR z-scores (r = 0.215, p = 0.012). The ASMM z-scores were negatively associated with the FT4 levels (r = −0.255, p = 0.003). Dyslipidemia was prevalent. TSH was correlated with LDL cholesterol (r = 0.472, p < 0.001) and triglycerides (r = 0.232, p = 0.05). Conclusions: Elevated thyroid-stimulating levels were linked to higher BMI and lower MFR levels. Our findings on the relationship between thyroid function and lipid profile underscore the necessity of optimizing thyroid balance and implementing targeted lifestyle interventions to improve body composition in young patients with thyroid disorders. Full article

Objectives: This study aimed to investigate the relationship between excessive postpartum iodine intake and the incidence of thyroid disease in mothers, as well as child growth and development. Methods: Of 1054 participants in the 2019 nationwide survey that assessed maternal postpartum iodine intake, 684 mothers participated in a follow-up study. Data on maternal thyroid disease incidence and child growth and development from infant or toddler health checkups were collected. Iodine and nutrient intake were assessed using three-day dietary records, and serum thyroid hormones (triiodothyronine (T3), thyroid-stimulating hormone (TSH), and free thyroxine (free T4)) were measured. Relative risks (RRs) were estimated using Poisson regression analysis. Results: Among the 684 participants, 23 (3.4%) were diagnosed with thyroid disease by a physician during the follow-up period. The incidence of maternal thyroid disease was not significantly associated with excessive iodine intake, even after adjusting for confounding factors. Additionally, excessive maternal iodine intake was not related to subclinical hypothyroidism in mothers or child growth and development. Conclusions: After a three-year follow-up, no relationship was observed between high postpartum iodine intake and the risk of thyroid disease. Large-scale longitudinal studies are required to evaluate the long-term effects of excessive postpartum iodine intake on maternal health and child growth and development. Full article

Objective: This study investigated the impact of maternal subclinical hypothyroidism on fetal thymus size and development and explored how inadequate thyroid hormone production in pregnant women affects the fetal thymus. Methods: Conducted at the Giresun Obstetrics, Gynecology, and Pediatrics Training and Research Hospital, this case–control study involved 86 pregnant women, 43 with hypothyroidism and 43 without. Maternal thyroid function was assessed using TSH and free T4 levels, and fetal thymus size and thymus–thorax ratio were measured using ultrasound. Exclusion criteria were chronic hypertension, gestational hypertension or eclampsia, multiple pregnancies, infectious diseases, renovascular diseases, diagnosed with hypothyroidism prior to pregnancy and other endocrine disorders, fetal cardiac diseases, and morbid obesity. Data collected included maternal age, gestational week, number of pregnancies, parity, number of living children, thyroid-stimulating hormone (TSH) and Free thyroxine 4 (T4) levels, and fetal thymus measurements (transverse diameter and thymus/thorax ratio). Statistical analyses were performed using the Mann–Whitney U test and logistic regression analysis. The relationships between TSH, thymus diameters, thorax diameters, and the thymus–thorax ratio were evaluated using Spearman’s correlation coefficient. Results: The thymus–thorax ratio was significantly reduced in the hypothyroid group (p = 0.003). Logistic regression analysis identified TSH as an independent risk factor for a low thymus–thorax ratio, with each unit increase in TSH associated with a 1.345-fold higher likelihood of having a low thymus–thorax ratio. A significant negative correlation was found between TSH levels and the TTR ratio (Spearman’s correlation coefficient r = −0.338, p = 0.001). Conclusions: An association was identified between maternal TSH levels and the thymus–thorax ratio, with increasing TSH levels correlating with a decrease in the thymus–thorax ratio. Regular monitoring of thyroid hormone levels during pregnancy and appropriate replacement treatment in cases of deficiency are crucial for optimal fetal thymus development. Further multicenter studies are needed to confirm these findings and investigate the long-term implications of altered fetal thymus development. Full article

Thyroid dysfunction is associated with a number of neuropsychiatric manifestations. Cognitive decline is a common feature of hypothyroidism and clinical or subclinical hyperthyroidism. In addition, there is a significant association between thyroid hormone (TH) levels and the degree of cognitive impairment in Parkinson’s disease (PD). The pathophysiology of TH-related neurodegeneration include changes in the blood–brain barrier, increased cellular stress, altered processing of β-amyloid precursor protein and the effect of TH on neuronal cell viability. The neurotoxicity of TH is partially mediated by the thyroid hormone responsive protein (THRP). This protein is 83% homologous to mouse c-Abl-interacting protein-2 (Abi2), a c-Abl-modulating protein with tumor suppressor activity. In cell cultures, increasing THRP expression either with TH treatment or exogenously through transfecting neuronal or PC 12 cells causes cell necrosis. The expression of exogenous THRP in other cells such as the colonic epithelial cell line Caco-2 and the glial cell line U251 has no effect on cell viability. The effect of THRP on cell viability is not modulated by c-Abl tyrosine kinase. The causal relationship between specific biochemical perturbations in cerebral tissue and thyroid dysfunction remains to be elucidated. Full article