Higher Risk Of Thyroid Dysfunction Research Articles

Thyroid dysfunction in India: what is different

Thyroid dysfunction (TD) is a common endocrine condition worldwide. Thyroid hormone is essential for growth, development, and energy metabolism. TD if left untreated leads to various serious health consequences. Various risk factors for the development of TD are iodine deficiency, ageing, genetic susceptibility, smoking status, ethnicity, and endocrine disruptors. Indians are at high risk for the development of TD as compared to Caucasians. Indian thyroid patients differ than Caucasians in many aspects such as higher prevalence of congenital hypothyroidism and other TD, higher rate of progression of subclinical hypothyroidism (SCH) to overt hypothyroidism (OH), and lower prevalence of thyroid associated ophthalmopathy (TAO). In this article, we tried to summarize the current evidences regarding environmental and biological factors that place Indians at high risk of TD as compared to other ethnic groups. High prevalence and different characteristics of Indian TD call for investigation into cause of increased susceptibility and way to prevent TD at individual and population levels.

Cadmium Exposure was Associated with Sex-Specific Thyroid Dysfunction: Consistent Evidence from Two Independent Cross-Sectional Studies Based on Urinary and Blood Cadmium Measurements.

Population-based studies on the association between cadmium (Cd) exposure and thyroid function are limited and have shown conflicting results. Two independent cross-sectional studies using different Cd biomarkers were carried out in six rural areas with different soil Cd levels in China. Thyroid dysfunction was defined based on levels of thyroid stimulating hormone (TSH) and free thyroxine (FT4). Multivariable linear regression, multiple logistic regression, and restrictive cubic splines models were used to estimate the association between Cd and thyroid dysfunction. For both of the two independent studies, higher Cd levels were observed to be associated with lower TSH levels and higher risk of thyroid dysfunction. The negative relationship between urinary Cd and TSH was found in both total participants (β = - 0.072, p = 0.008) and males (β = - 0.119, p = 0.020) but not in females; however, the negative relationship between blood Cd and TSH was only found in females (β = - 0.104, p = 0.024). Higher urinary Cd was associated with higher risk of thyroid dysfunction (OR = 1.77, p = 0.031), while higher blood Cd was associated with higher risk of thyroid dysfunction (OR = 1.95, p = 0.011). Results from the two independent cross-sectional studies consistently suggested that higher Cd levels were associated with sex-specific thyroid dysfunction.

Roxadustat and transfusional iron overload induced hypothyroidism in a hemodialysis patient: a case report with a literature review

BackgroundAlthough roxadustat has been reported to cause central hypothyroidism, the details of the mechanisms and clinical characteristics of patients who are prone to developing hypothyroidism with roxadustat are uncertain.Case presentationA 53-year-old man with a 3-year history of hemodialysis due to diabetic kidney disease who had been treated with roxadustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, for 2 years was admitted to the hospital because of worsening gait disturbance and impaired consciousness. He had also acquired pure red cell aplasia associated with T-cell large granular lymphocytic leukemia and received multiple blood transfusions. Because his serum concentration of thyroid hormones was low, we diagnosed him with hypothyroidism, and his consciousness level recovered to normal with thyroid hormone replacement therapy. Computed tomography revealed a high-intensity atrophic thyroid gland, and magnetic resonance imaging showed diffusely reduced T2 and T1 signals of the pituitary anterior gland. These findings confirmed the accumulation of iron in the pituitary and thyroid glands. Combined pituitary stimulation tests with thyrotropin-releasing hormone, luteinizing hormone-releasing hormone, and corticotropin-releasing hormone revealed that the patient had pan-hypopituitarism. After discontinuation of roxadustat, the patient was treated with another hypoxia-inducible factor prolyl hydroxylase inhibitor, vadadustat. One month after switching medication, a stimulation test with thyrotropin-releasing hormone showed normal responses to thyroid-stimulating hormone. The patient was treated with levothyroxine 50 μg daily without any significant symptoms and is currently under follow-up observation as an outpatient.ConclusionsWe encountered a dialysis patient with roxadustat-induced hypothyroidism associated with transfusion iron overload. To our knowledge, this is the first case to clearly show that roxadustat can impair thyroid-stimulating hormone secretion in repeated thyrotropin-releasing hormone stimulation tests. Because the present patient had received roxadustat for more than 2 years before hypothyroidism became apparent, regular monitoring of the thyroid function may be needed in patients with renal anemia who have been treated with roxadustat, especially those at high risk of thyroid dysfunction.

Association of COVID-19 Infection with Subsequent Thyroid Dysfunction: An International Population-Based Propensity Score Matched Analysis.

Background: The COVID-19 pandemic's impact on thyroid function is a growing concern. Previous studies have produced inconclusive results, and there is a lack of comprehensive research into the long-term risks of thyroid dysfunction following COVID-19 infection. Methods: In this retrospective cohort study, we used data from the TriNetX international database, which includes electronic health records from a broad, diverse patient population. We compared patients with COVID-19 (cases) to those without (controls), matching for age, sex, race, and comorbidities using propensity score matching. The primary outcome was the diagnosis of thyroid dysfunction (thyrotoxicosis or hypothyroidism) within a 12-month period, analyzed using hazard ratios (HRs) and Kaplan-Meier curves, and stratified by age and sex. Results: Initially, the study included 1,379,311 COVID-19 patients and 6,896,814 non-COVID-19 patients from the TriNetX database. After matching, the cohorts were comparable in demographics and baseline characteristics. This study consistently demonstrated a significant increase in the risk of thyroid dysfunction, including thyrotoxicosis and hypothyroidism, among COVID-19 patients compared to non-COVID-19 patients. In the short term (3 months postexposure), the COVID-19 group exhibited a HR of 2.07 (95% confidence interval [CI] 2.01-2.12) for thyroid dysfunction, which included both thyrotoxicosis (HR 2.10, CI 1.92-2.29) and hypothyroidism (HR 2.08, CI 2.01-2.13). This heightened risk persisted over the long term (up to 12 months), with HRs indicating an ∼2.01-fold increased risk for overall thyroid dysfunction, a 1.8-fold increased risk for thyrotoxicosis, and a 2.04-fold increased risk for hypothyroidism. Subgroup analysis, stratified by age and sex, revealed a notably higher risk of thyroid dysfunction in patients aged 65 and above (HR 2.18, CI 2.11-2.25), compared to those in the under-65 age group (HR 1.97, CI 1.91-2.03). Both male and female patients were associated with an elevated risk, with females showing a slightly higher association with thyroid dysfunction (HR 2.12, CI 2.06-2.16) compared to males (HR 1.76, CI 1.69-1.82). Conclusions: COVID-19 infection was associated with an increased risk of thyroid dysfunction, including thyrotoxicosis and hypothyroidism, regardless of age or sex, during a 12-month follow-up period. Further research is required to validate these findings.

Navigating Thyroid Dysfunction and Comorbidities Among University Students in Abbottabad, Pakistan - A Cross-Sectional Evaluation of Screening Tool for Thyroid Dysfunction.

Thyroid dysfunction has a direct role in diagnosing, and assessment and indicates the development of thyroid carcinoma. This study aimed to assess thyroid dysfunction through medical camps in different age and sex groups in students of Comsats University Abbottabad Pakistan. In this study, a cross-sectional survey design was used. For data collection, a two-day medical camp was set in the Comsats University Abbottabad campus. The students were examined physically for symptoms of thyroid dysfunction using the survey questionnaire specifically designed for this study. The current research revealed that 78 out of 1032 students, or 7.6% of the population, had thyroid disease. Although 39.3% (=406) were found to have low risk, followed by 36.7% (n=379) had moderate risk and 23.9% (n=247) had high risk of thyroid dysfunction. Altogether, 6.1% (n=63) of the students had high blood pressure (BP), 3.2% (n=33) had high cholesterolemia, 3.4% (n=33) had angina, and 0.9% (n=9) had diabetes mellitus (DM). In relation, students who exhibit signs and symptoms that last longer than five weeks include 42.2% (n=435) who felt the need for excessive sleep, 35.3% (n=364) who felt tired, 36.8% (n=380) who had trouble concentrating and 30.1% (n=311) who had palpitations. The high risk of thyroid being seen predominantly in students between the ages of 15-20 years (31.2%, n=148), as opposed to other age groups (p=0.001). Similar to this, women having a higher risk of thyroid disease (26.5%) than men (22.8%) (p =0.001). In conclusion, few students suffer with thyroid found to have high risk of thyroid disease. This method of questionnaire-based screening for thyroid dysfunction is cost-effective, with no additive risk of adverse effects from excessive screening, and could help in the early detection of thyroid and help avoid excess costs related to thyroid dysfunction and cancer screening.

Thyroid function analysis after roxadustat or erythropoietin treatment in patients with renal anemia: a cohort study

Purpose This cohort study was designed to explore whether roxadustat or erythropoietin could affect thyroid function in patients with renal anemia. Methods The study involved 110 patients with renal anemia. Thyroid profile and baseline investigations were carried out for each patient. The patients were divided into two groups: 60 patients taking erythropoietin served as the control group (rHuEPO group) and 50 patients using roxadustat served as the experimental group (roxadustat group). Results The results indicated that there were no significant differences in serum total thyroxine (TT4), total triiodothyronine (TT3), free triiodothyronine (FT3), free thyroxine (FT4) or thyroid stimulating hormone (TSH) between the two groups at baseline. After treatment, TSH, FT3, and FT4 were significantly lower in the roxadustat group than in the rHuEPO group (p < 0.05). After adjusting for age, sex, dialysis modality, thyroid nodules and causes of kidney disease, Cox regression showed that roxadustat was an independent influencing factor on thyroid dysfunction (HR 3.37; 95% CI 1.94–5.87; p < 0.001). After 12 months of follow-up, the incidence of thyroid dysfunction was higher in the roxadustat group than in the rHuEPO group (log-rank p < 0.001). Conclusion Roxadustat may lead to a higher risk of thyroid dysfunction, including low TSH, FT3 and FT4, than rHuEPO in patients with renal anemia.

TO STUDY SMALL FOR GESTATIONAL AGE AS A RISK FACTOR FOR THYROID DYSFUNCTION

Introduction: Babies with a birth weight and/or length below the 10th percentile of a population of the same gestational age are dened small-forgestational-age (SGA). Children born prematurely or small for gestational age are at a higher risk of thyroid dysfunction. Intrauterine growth retardation and the delivery of SGA infants may have a variety of reasons. This illness is characterised by several endocrine-metabolic changes and pathophysiological processes. It has been shown that there are greater rates of diseases including cardiovascular events, metabolic syndrome, hypertension, and obesity. These changes may also have an impact on future health in infancy and adulthood. There aren't many research that compare the thyroid function of SGA and AGA neonates. For newborn plasma concentrations of T4 and TSH, contradictory ndings have been reported. The study was conducted to observe the relationship that the weight and/ Objective: or the gestational age plays on the thyroid function of the babies. This retrospective study was conducted in a tertiary care cent Materials And Methods: re. This study focused on the day 3 TSH, Ft4 value of the SGA babies compared with the AGA babies. Preterm and term Results: SGA babies had considerably lower blood T4 concentrations and higher TSH values as compared to AGA neonates (P=0.0001). SGA babies had a hi Conclusion: gher incidence of transient hypothyroidism and required accurate follow-up and close monitoring of thyroid function.

Thyroid dysfunction as a long-term post-COVID-19 complication in mild-to-moderate COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), may lead to thyroid disorders, including both thyrotoxicosis and suppression of thyroid function. The aim of the present study was to assess the post-COVID-19 effects on thyroid function in patients without history of thyroid disease after complete recovery from mild-to-moderate COVID-19. Thyroid function tests [thyroid-stimulating hormone (TSH), free thyroxine (fT4), antithyroid antibodies] were performed on 113 patients (median age of 43.0 years; 31.0% male) two months after initial SARS-CoV-2 infection. TSH and fT4 were determined again one month later in this observational, prospective study. Thyroid dysfunction was registered in 61.1% of the patients (78.3% subclinical hypothyroidism, 13% subclinical hyperthyroidism and 8.7% overt hypothyroidism) two months after COVID-19. Moderate rather than mild manifestation of COVID-19 was significantly associated with a higher risk of thyroid dysfunction (OR 5.33; 95% CI: 1.70–16.69, p = 0.002), presence of thyroglobulin antibodies and need for levothyroxine therapy. At the follow-up, the subclinical hypothyroidism persisted in 28.3% of the subjects. Moreover, the TSH level was significantly reduced in comparison to the second month after the initial COVID-19 infection in all the patients (p < 0.001), but not in those with subclinical hypothyroidism and without hormone replacement therapy. Our findings indicate that COVID-19 could have long-term, negative effects on thyroid function. Therefore, thyroid function testing should be included in the follow-up algorithm of COVID-19 survivors.

Thyroid function in < 32 weeks gestation preterm infants

IntroductionPreterm newborns (PN) have a higher risk of thyroid dysfunction than term newborns (TN). This condition may go unnoticed in neonatal screening due to a late elevation of thyrotropin (TSH) in these patients. ObjectiveEvaluate thyroid function in the second week of life in PN of < 32 weeks gestation (WG), and to identify factors associated to its alteration. Patients and methodsA retrospective study was performed in neonates of < 32 weeks gestation (WG), in whom thyroid function was determined. An analysis was performed on thyroxine (T4L) and TSH levels, as well as their association with perinatal and neonatal outcomes. ResultsThe study included a total of 358 patients with mean gestational age (GA) of 29.3 weeks, and mean birth weight (BW) 1127 grams. A linear correlation was found between T4L and BW (correlation coefficient (R) 0.356; p < 0.001) and GA (R = 0.442; p < 0.001). TSH values were associated with small for gestational age (SGA 5.3 mU/L [1.5-37]; non-SGA 2.89 mU/L [0.2-19.5]; p < 0.001), inotropic support (Yes 3.98 mU/L [0.6-22.9]; No 3.16 mU/L [0.2-37]; p = 0.019) and BW (R = -0.249; p < 0.001). Nine (2.5%) patients were treated with levothyroxine, of whom six were SGA. ConclusionsThyroid function analysis in the second week of life helps to identify asymptomatic newborns with risk of thyroid dysfunction. SGA newborns are at higher risk of thyroid function alterations.

Significant Association of Antiepileptic Drug Polytherapy with Decreased FT4 Levels in Epileptic Patients.

Epileptic patients have to continue anti-epileptic drugs (AED) over a long period of time which can have deleterious effects on the endocrine system including the thyroid hormones with rare check. Risk factors for the development of thyroid dysfunction are still unclear. Therefore the aim of study was to evaluate thyroid functions in epileptic patients receiving anti-epileptic drugs (AED) as monotherapy and polytherapy and to determine potential risk of low thyroid function in epileptic patients receiving treatment. This cross-sectional study included 100 epilepsy patients more than 12years of age. Serum levels of free thyroxin (FT4), free triiodothyronine (FT3), and thyroid stimulating hormone (TSH) were evaluated in all subjects in addition to serum AED levels. TSH levels were found to be significantly higher in the polytherapy subgroup (p < 0.05) in comparison to the monotherapy group. 44% of the patients in the VPA monotherapy group had raised TSH levels and 41.2% of the patients on CBZ had low FT4. A significant negative correlation was observed between CBZ and FT4 (p < 0.05). Female sex and old age were additional risk factors detected for deranged thyroid function. Female patients with epilepsy, an older age and AED polytherapy were found to be associated with a higher risk of thyroid dysfunction. Thus, Thyroid function in these patients should be monitored closely. In conclusion, we observed significant changes in thyroid hormone levels in patients receiving antiepileptic treatment in both monotherapy and polytherapy. Elevated CBZ levels were significantly associated with decreased FT4 levels.

Función tiroidea en el recién nacido prematuro con edad gestacional igual o menor a 32 semanas

IntroductionPreterm newborns (PN) have a higher risk of thyroid dysfunction than term newborns (TN). This condition may go unnoticed in neonatal screening due to a late elevation of thyrotropin (TSH) in these patients. ObjectiveEvaluate thyroid function in the second week of life in PN of < 32 weeks gestation (WG), and to identify factors associated to its alteration. Patients and methodsA retrospective study was performed in neonates of < 32 weeks gestation (WG), in whom thyroid function was determined. An analysis was performed on thyroxine (T4L) and TSH levels, as well as their association with perinatal and neonatal outcomes. ResultsThe study included a total of 358 patients with mean gestational age (GA) of 29.3 weeks, and mean birth weight (BW) 1127 grams. A linear correlation was found between T4L and BW (correlation coefficient (R) 0.356; p < 0.001) and GA (R = 0.442; p < 0.001). TSH values were associated with small for gestational age (SGA 5.3 mU/L [1.5-37]; non-SGA 2.89 mU/L [0.2-19.5]; p < 0.001), inotropic support (Yes 3.98 mU/L [0.6-22.9]; No 3.16 mU/L [0.2-37]; p = 0.019) and BW (R = -0.249; p < 0.001). Nine (2.5%) patients were treated with levothyroxine, of whom six were SGA. ConclusionsThyroid function analysis in the second week of life helps to identify asymptomatic newborns with risk of thyroid dysfunction. SGA newborns are at higher risk of thyroid function alterations.

Amiodarone-associated thyroid dysfunction in adult patients with congenital heart disease: a nationwide health insurance data analysis including &amp;gt;50.000 individuals

Abstract Background Arrhythmias are common in adult patients with congenital heart disease (ACHD). Amiodarone is widely used as an antiarrhythmic agent. Thyroid dysfunction represents a serious complication of amiodarone treatment. Systematic data on the prevalence of thyroid dysfunction, risk factors for complications and treatment options are lacking. Purpose Based on data from one of the largest German Health Insurance Companies (BARMER GEK, approx. 9 million members), we performed a retrospective analysis investigating the rate of thyroid complications under active amiodarone therapy in ACHD patients and a comparison group of cardiac patients without congenital heart disease on amiodarone between 2005 and 2018. Result Overall, 910 ACHD (34% female; median age 66 y; CHD complexity mild, moderate, severe in 64.6%, 23.6%,11.8%, respectively) and 49,782 non-ACHD patients (37% female, median age 73.4 y) received prescriptions for amiodarone without documented pre-existing thyroid disease or use of thyroid medication. Over a treatment period of 184,770 patient-years, 10,874 incidents of thyroid dysfunction occurred in the non-ACHD and 201 in the ACHD cohort, corresponding to an event-rate of 6% and 5.3% per patient year, respectively. Overall, 23.5% of the ACHD patients developed thyroid dysfunction (56.71% hypothyroidism, 43.3% hyperthyroidism). Risk factors for developing thyroid dysfunction on time dependent Cox-analysis were female gender (hazard ratio [HR] 1.44, 95% CI: 1.39–1.50; p&amp;lt;0.001), lower patient age (HR: 0.96 per 10 years, 95% CI: 0.94–0.98, p&amp;lt;0.001) renal dysfunction (HR 1.24, 95% CI: 1.19–1.29, p&amp;lt;0.001), history of alcohol abuse (HR 1.17, 95% CI: 1.07–1.27, p,0.001) and smoking (HR 1.12, 95% CI: 1.06–1.19, p&amp;lt;0.001). Congenital heart disease itself was not associated with a higher risk of thyroid dysfunction (HR 0.96, 95% CI: 0.83–1.10, p=0.53). Within the ACHD group, patients with complex disease had a significantly higher risk of thyroid dysfunction (HR 1.5, 95% CI: 1.00–2.25, p=0.049) compared to patients with simple diagnoses. Once thyroid disease occurred, 48.5% of patients were continued on amiodarone therapy, 12.8% of patients underwent an electrophysiologic procedure and only 2.1% of patients received class I antiarrhythmics. Specific thyroid therapy included thyroxine (62.6% of hypothyroid patients) or thiamazole (22.6% of hyperthyroid patients). Only 2.3% of patients required surgery or radiotherapy within 6 months after thyroid dysfunction. Conclusion Amiodarone-associated thyroid dysfunction is a frequent complication in ACHD patients. Overall, one in 4 ACHD patients on amiodarone developed thyroid dysfunction in our study. In itself, ACHD does not seem to increase the risk of thyroid dysfunction. However, female gender, complexity of disease, younger age and renal dysfunction emerged as independent risk factors. When amiodarone therapy can not be avoided, close follow-up and regular thyroid function tests are recommended. Funding Acknowledgement Type of funding source: None

Liver toxicity as a limiting factor to the increasing use of immune checkpoint inhibitors.

SummaryImmune checkpoint inhibitors (ICIs) improve clinical outcomes in patients suffering from different types of cancer. Liver toxicity is one of the immune-related adverse events associated with immunotherapy; although not common, its management is challenging as it is extremely heterogeneous in terms of presentation and severity. Differences in the development and evolution of ICI-related toxicity in healthy or cirrhotic livers have not yet been elucidated. Assessing causality is key to diagnosing ICI-induced liver toxicity; liver biopsies can assist not only in the differential diagnosis but also in assessing the severity of histological liver damage. The current classification of severity overestimates the grade of liver injury and needs to be revised to reflect the views of hepatologists. Spontaneous improvements in ICI-related liver toxicity have been reported, so corticosteroid therapy should probably be individualised not systematic. The reintroduction of ICIs in a patient with previous immune-mediated hepatitis may be possible, but the risk/benefit ratio should be considered, as the risk factors for hepatitis recurrence are currently unclear. The management of these patients, requiring a balance between efficacy, toxicity and specific treatments, necessitates multidisciplinary collaboration. The incidence of immune-related liver toxicity will continue to rise based on the increasing use of ICIs for most cancers, mandating improved understanding and management of this complication.

Obese Subjects with Non-Alcoholic Fatty Liver Disease Have a Higher Risk of Thyroid Dysfunction

Objectives The effects of obesity on thyroid function have not been well established. The aim of this study was to investigate the effects of body mass index (BMI) and/or non-alcoholic fatty liver disease (NAFLD) on thyroid function. Methods A retrospective longitudinal analysis was conducted among subjects who underwent comprehensive health check-ups at least four times between 2008 and 2017. Thyroid function was investigated according to BMI or presence of NAFLD at the end of follow-up. The subjects were divided into four groups: control (n = 216), subjects with obese (n = 94), subjects with NAFLD (n = 48), and subjects with obese + NAFLD (n = 93). Obesity was defined as BMI ≥ 25 kg/m2. Results During the mean follow-up of 6.8 years (6.8 ± 1.2 years), 42 of the 451 subjects (9.3%) had subclinical hypothyroidism (SCH) but no subjects developed overt hypothyroidism. In multivariate Cox proportional hazard analysis, after adjustment for age, sex, smoking, and baseline thyroid stimulating hormone level, obese subjects with NAFLD had a higher risk of SCH than the control group. Conclusions The obese subjects with NAFLD had a higher risk for SCH in the future.

Association of antithyroglobulin antibodies with the development of thyroid dysfunction induced by nivolumab.

Thyroid dysfunction (TD) induced by immune checkpoint inhibitors is not sufficiently understood. The purpose of this retrospective observational study was to identify risk factors and the clinical course of TD induced by nivolumab. Patients with advanced solid tumors who were treated with nivolumab from March 2009 through to March 2016 at the National Cancer Center Hospital (Tokyo, Japan) were included. Thyroid function and antithyroid Abs from serum samples among all patients were evaluated at baseline and during nivolumab treatment. Overt hypothyroidism was defined as low serum‐free T4 together with elevated thyroid‐stimulating hormone (TSH) >10 μIU/mL. Thyrotoxicosis was defined as low TSH with elevated free T4 and/or free T3. We defined thyroid autoimmunity as the presence of antithyroid Abs at baseline, including antithyroid peroxidase Abs and antithyroglobulin Abs (TgAb). Twenty‐three (14%) of a total of 168 patients developed TD, including 17 cases of hypothyroidism and 20 of thyrotoxicosis. Thyrotoxicosis followed by hypothyroidism occurred in 14 cases. Fourteen of 35 patients (40%) with thyroid autoimmunity developed TD vs 9 of 133 (7%) without (odds ratio 9.19; 95% confidence interval [CI], 3.53‐23.9). In multivariate analysis, elevated TSH and TgAb at baseline were significantly associated with the development of TD, with odds ratio of 7.36 (95% CI, 1.66‐32.7) and 26.5 (95% CI, 8.18‐85.8), respectively. Association between TD and elevated antithyroid peroxidase Abs at baseline was not significant. These results suggest that patients with pre‐existing TgAb and elevated TSH at baseline are at high risk of TD.

Identifying and treating subclinical thyroid dysfunction in pregnancy: emerging controversies.

Thyroid hormones are essential for an adequate growth and development of the fetus. In addition to the classical association between maternal hypothyroidism and neurological impairment in the progeny, other adverse reproductive events have been associated with maternal thyroid dysfunction including infertility, miscarriage and preterm delivery. Although all scientific societies endorse the treatment of overt hypothyroidism; the management and/or treatment of subclinical hypothyroidism, hypothyroxinemia or antithyroid antibody-positive women should be considered with caution. Important trials have found no clear benefit of treatment of subclinical hypothyroidism in terms of cognitive outcomes; however, other interventional studies appear to reduce some of the obstetric and perinatal complications. As a result, the dilemma between universal screening or selective screening of women at high risk of thyroid dysfunction during pregnancy remains unresolved. Despite this, levothyroxine is also now regularly prescribed by gynaecologists and centres for reproductive medicine. In this context, there is increasing concern regarding the risk of over diagnosis and subsequent potential overtreatment. Taken together, we need to reconsider how thyroid dysfunction should be identified in pregnant women and highlight the arguments for and against the use of levothyroxine in obstetric practices. Our main findings: the mismatch between the guidelines recommendations and the use of LT4 in clinical settings as well as the disparity of criteria between scientific societies from different medical specialties. In conclusion, it is essential to reach agreements between both endocrinologists and obstetricians.

Iodinated Contrast Media-Induced Thyroid Dysfunction in Euthyroid Nodular Goiter Patients.

The risks of thyroid dysfunction after iodinated contrast media exposure in patients with euthyroid nodular goiter are largely unknown. This observational, retrospective cohort study included a random selection of one million people in Taiwan. All patients with iodinated contrast media exposure during this study period were selected. Patients with euthyroid nodular goiter were identified as cases, while patients without thyroid nodule were selected as controls. We followed these patients until the first event of thyroid dysfunction including hyperthyroidism or hypothyroidism after iodinated contrast media exposure. A total of 334 cases and 2672 matched controls were selected in this study. The mean age of cases and controls were 58.6 and 58.4 years old, and mean follow-up durations were 2.1 and 2 years respectively. After adjustment, patients with euthyroid nodular goiter had a higher risk of thyroid dysfunction (hazard ratio 5.43, [confidence interval (CI) 3.01-9.80]) compared with controls after iodinated contrast media exposure. In the subgroup analysis, the risks of hyperthyroidism and hypothyroidism in cases compared with controls were 5.77 [CI 2.64-12.62] and 4.95 [CI 2.15-11.40] respectively. Half of the euthyroid nodular goiter cases developed thyroid dysfunction within one year after iodinated contrast media exposure. Interestingly, all thyroid-related comorbidities and drug prescriptions did not increase the risk of thyroid dysfunction. Presence of euthyroid nodular goiter was associated with higher risk of thyroid dysfunction including hyperthyroidism and hypothyroidism after iodinated contrast media exposure.

Iodinated Contrast Media Increased the Risk of Thyroid Dysfunction: A 6-Year Retrospective Cohort Study.

The risks of thyroid dysfunction after iodinated contrast media (ICM) exposure are largely unknown, especially in Asian populations. The objective was to determine whether ICM exposure in patients with normal thyroid would increase the risk of thyroid dysfunction, including hyperthyroidism or hypothyroidism. This was a retrospective cohort study including a random selection of 1 million people in 2005. General population of Taiwan was studied. Patients with ICM exposure were identified as cases, whereas patients without any ICM exposure were selected as controls. Interventions included ICM exposure or nonexposure in normal thyroid function patients. The primary endpoint was the composite risk of thyroid dysfunction associated with ICM exposure. A total of 19 642 cases and 78 568 matched controls were recruited in this study. The mean ages of ICM exposure and nonexposure were 53.9 and 53.6 years, respectively, and mean follow-up durations were 4.1 and 5.6 years, respectively. After adjustment, patients with ICM exposure had a significantly higher risk of thyroid dysfunction (hazard ratio, 1.46; 95% confidence interval [CI], 1.29-1.66). In the subgroup analysis, the adjusted hazard ratios of hyperthyroidism and hypothyroidism compared with controls were 1.22 (95% CI, 1.04-1.44) and 2.00 (95% CI, 1.65-2.44), respectively. ICM exposure was associated with higher risk of thyroid dysfunction, including hyperthyroidism and hypothyroidism.

Prevalence of thyroid dysfunction in women in early pregnancy: does it increase with maternal age?

Recent studies report high rates of thyroid disorders in pregnant women. However, the need for universal thyroid screening remains controversial. Our aim was to estimate the prevalence of thyroid dysfunction (TD) during pregnancy and to analyse the association with maternal age. We conducted a cross-sectional study in a referral centre in collaboration with the primary care units from April 2010 to March 2011. The study included 2509 consecutive pregnant women resident in an iodine-sufficient area, mean age 32 years (range 16-47) who were universally screened for TD in their first trimester (median gestation 8 weeks, range 4-13 weeks). Thyroid-stimulating hormone (TSH) and free T4 (FT4) were analysed during the first antenatal visit. We applied first trimester-specific population-based TSH and FT4 reference ranges. We identified 416 women with positive TD screening [16·6%, 95% confidence interval (95% CI) 15·1-18·0]. Of these, 47 had overt hypothyroidism (1·9%), 90 subclinical hypothyroidism (3·6%), 23 overt hyperthyroidism (0·9%), 20 subclinical hyperthyroidism (0·8%) and 236 had isolated hypothyroxinaemia (9·4%). Applying a logistic regression model, age ≥30 years was not associated with a higher risk of TD [odds ratio (OR) 0·85, 95% CI 0·67-1·08] or hypothyroidism (OR 0·72, 95% CI 0·50-1·06). TD affects one in six pregnant women in an iodine-sufficient population. Maternal age ≥30 years do not increase the risk of TD.

Increased waist circumference is independently associated with hypothyroidism in Mexican Americans: replicative evidence from two large, population-based studies.

BackgroundMexican Americans are at an increased risk of both thyroid dysfunction and metabolic syndrome (MS). Thus it is conceivable that some components of the MS may be associated with the risk of thyroid dysfunction in these individuals. Our objective was to investigate and replicate the potential association of MS traits with thyroid dysfunction in Mexican Americans.MethodsWe conducted association testing for 18 MS traits in two large studies on Mexican Americans – the San Antonio Family Heart Study (SAFHS) and the National Health and Nutrition Examination Survey (NHANES) 2007–10. A total of 907 participants from 42 families in SAFHS and 1633 unrelated participants from NHANES 2007–10 were included in this study. The outcome measures were prevalence of clinical and subclinical hypothyroidism and thyroid function index (TFI) – a measure of thyroid function. For the SAFHS, we used polygenic regression analyses with multiple covariates to test associations in setting of family studies. For the NHANES 2007–10, we corrected for the survey design variables as needed for association analyses in survey data. In both datasets, we corrected for age, sex and their linear and quadratic interactions.ResultsTFI was an accurate indicator of clinical thyroid status (area under the receiver-operating-characteristic curve to detect clinical hypothyroidism, 0.98) in both SAFHS and NHANES 2007–10. Of the 18 MS traits, waist circumference (WC) showed the most consistent association with TFI in both studies independently of age, sex and body mass index (BMI). In the SAFHS and NHANES 2007–10 datasets, each standard deviation increase in WC was associated with 0.13 (p < 0.001) and 0.11 (p < 0.001) unit increase in the TFI, respectively. In a series of polygenic and linear regression models, central obesity (defined as WC ≥ 102 cm in men and ≥88 cm in women) was associated with clinical and subclinical hypothyroidism independent of age, sex, BMI and type 2 diabetes in both datasets. Estimated prevalence of hypothyroidism was consistently high in those with central obesity, especially below 45y of age.ConclusionsWC independently associates with increased risk of thyroid dysfunction. Use of WC to identify Mexican American subjects at high risk of thyroid dysfunction should be investigated in future studies.