Assessment of iodine nutritional status and gestational thyroid function reference ranges during the first trimester of pregnancy in Taiwan.

BACKGROUND: Iodine nutrition is critical for fetal neurodevelopment in the first trimester of pregnancy, a period associated with dramatic changes in thyroid function. The aim of this study was to evaluate iodine nutritional status and thyroid function reference ranges in the first trimester in Taiwan. METHODS: Pregnant women aged 20 years and above in the first trimester were recruited in Taipei Veterans General Hospital, Taiwan from March 2019 to July 2022. Each participant provided a spot urine sample for measurement of urinary iodine concentration (UIC) and a blood sample for checkup of thyroid function and thyroid autoantibodies. A simple food frequency questionnaire was also completed. RESULTS: A total of 209 women with a mean age of 32.9 ± 4.4 years were enrolled. The median UIC was 160.9 µg/L (interquartile range [IQR]: 105.0-246.2 µg/L), indicating overall iodine sufficiency. The gestational thyroid function reference ranges were: thyroid stimulating hormone (TSH) (median: 0.93 [0.007-2.9] µIU/mL), free T4 (1.3 [0.93-2.2] ng/dL), free T3 (3.0 [2.3-5.0] ng/dL), total T4 (9.9 [6.4-16.9] ng/dL), and total T3 (135 [88-231] ng/dL). If the nonpregnant reference range of serum TSH was used, eight women (4.8%) would be misclassified as having subclinical hyperthyroidism, and two women (1.2%) with subclinical hypothyroidism would be missed. In multivariate analysis, nulliparous (adjusted odds ratio [OR] from model 1-3: 2.02, 2.05, 2.02; 95% CI, 1.08-3.77, 1.10-3.81, 1.11-3.66; p = 0.027, 0.023, 0.022, respectively) and multivitamin nonusers (adjusted OR from model 1-3: 1.86, 1.85, 1.78; 95% CI, 1.04-3.34, 1.03-3.32, 1.004-3.71; p = 0.038, 0.039, 0.049, respectively) had increased odds of having lower UIC levels <150 µg/L. CONCLUSION: The iodine nutritional status in the first trimester is adequate in Taiwan; however, certain subgroups such as nulliparous and multivitamin nonusers are still at risk for iodine deficiency. Gestational thyroid function reference ranges are needed for correct diagnosis of thyroid dysfunction in pregnancy.

Effects of Subacute Exposure of Dibutyl Phthalate on the Homeostatic Model Assessment, Thyroid Function, and Redox Status in Rats.

Dibutyl phthalate is an endocrine disruptor used in a wide range of industrial and agriculture applications. The present study focuses on elucidating the effect of subacute exposure (4-weeks) of DBP on insulin and its sensitivity indexes, oxidative status, thyroid function, energy metabolites, serum biochemistry, and anthropometry in rats. A total of 64 rats were divided into 4 treatment groups as mg DBP/Kg body weight per day: (a) 0 mg/Kg (control), (b) 10 mg/Kg (DBP-10), (c) 50 mg/Kg (DBP-50), and (d) 100 mg/Kg (DBP-100). The rats in each treatment (n = 16) were further divided into male (n = 8) and female (n = 8) rats for studying treatment and gender interactions. Intraperitoneal glucose tolerance test (IPGTT) was performed on the 21st day. Anthropometry, nutritional determinants, fasting plasma glucose, fasting plasma insulin, homeostatic model assessment (HOMA), thyroid hormones, energy metabolites, and oxidative status were studied during the experimental period. Two-way ANOVA was used to analyze the data (p < 0.05). Tukey's posthoc test was used for pair-wise comparisons. DBP increased body weight gain and feed efficiency in an inverted nonmonotonic U-shaped fashion. Hyperglycemia and increased blood glucose area under the curve were observed in DBP-100 at 120 minutes in IPGTT. The HOMA also showed a linear monotonic contrast. Thyroxin decreased significantly in the DBP-100 rats, whereas malondialdehyde, nonesterified fatty acids, and beta hydroxyl butyrate were increased with the DBP treatments. In conclusion, DBP could be attributed to the development of hyperglycemia and insulin resistance in rats. Further investigations into the lipid peroxidation pathways can improve our understanding of the mechanisms involved in metabolic disruption.

Thyroid function assessment before and after diagnosis of schizophrenia: A community-based study.

Alterations in thyroid hormone levels may affect brain and mental disorders. Conversely, schizophrenia and its antipsychotic treatments can affect thyroid hormone levels. However, data on thyroid hormone levels during the course of schizophrenia disorder are scant. The aim of the study was to assess the rate of thyroid hormone disorders in outpatients before and after diagnosis of schizophrenia. A retrospective matched-control design was used. The cohort included 1252 patients suffering from ICD-10 schizophrenia, and 3756 control subjects matched for gender, age, socioeconomic status, and origin. All were identified from the database of a large health management organization. The pertinent clinical data were collected from the electronic medical records. There was no significant between-group difference in the distribution of thyroid-stimulating hormone levels. Before diagnosis, both groups had a similar rate of hypothyroidism. After diagnosis of schizophrenia and initiation of antipsychotic treatment, the rate of hypothyroidism was significantly higher in the patient group. It remained significantly higher after exclusion of patients receiving lithium. The increased rate of hypothyroidism in patients with schizophrenia after, but not before, the diagnosis of schizophrenia suggests that antipsychotic medications may affect thyroid hormone levels. Screening for thyroid disorders is warranted in patients with schizophrenia under antipsychotic treatment.

Pitfalls in the assessment of gestational transient thyrotoxicosis.

Gestational transient thyrotoxicosis (GTT) is associated with direct stimulation of the maternal thyroid gland by human chorionic gonadotropin (hCG). It is characterized by slightly higher thyroid hormone and lower thyroid-stimulating hormone (TSH) levels in early pregnancy and mild or no symptoms. While GTT must be distinguished from Graves' disease (GD), which is associated with maternal and fetal complications, treated GD and new-onset GD in pregnancy are occasionally challenging to distinguish. Evaluating serum hCG levels and TSH receptor antibody (TRAb) titers can help, but the results are not irrefutable due to pregnancy-related immunosuppression. Moreover, GTT can follow unusual clinical courses in relation to some pregnancy complications. Excessive hCG production can cause severe GTT symptoms in patients with hyperemesis gravidarum, trophoblastic disease, or multiple pregnancies. Thyrotoxicosis can emerge beyond the second trimester in patients with gestational diabetes mellitus and mirror syndrome, because of delayed elevations in the hCG levels. Detailed knowledge about GTT is necessary for correct diagnoses and its appropriate management. This review focuses on the diagnosis of GTT, and, particularly, its differentiation from GD, and unusual clinical conditions associated with GTT that require comprehensive management.

Assessment of iodine supplementation program on thyroid function in Sudan.

The aim of this Study is to investigate whether the Iodine Supplementation Programme is successful or not. This Programme was implemented in Nyala to treat the Iodine deficiency. In this Study Nyala was selected to act as (a study area), due to the history of Iodine deficiency of this region, while Khartoum was selected to act as (a control area). 2000 samples were collected from Khartoum versus 450 samples from Nyala. Thyroxine (T4) and triiodothyronine (T3) levels in two regions were measured and performed by using radioimmunoassay (RIA), also the immunoradiometric assay (IRMA) used for measurement of thyroid stimulating hormone (TSH). The obtained results analyzed by using Statistical Package for Social Sciences (SPSS). (Coherent retrospective) used to determine differences between the study groups. The results of this study showed, there was no significant difference between the mean serum concentrations of T3 and TSH for Khartoum and Nyala. T4of Khartoum (117.93 ±â€¯42.797) nmol/L and the mean serum T4 of Nyala (114.54 ±â€¯45.526) nmol/L, the (P-value = 0.133).T3for Khartoum (1.8040 ±â€¯0.99047) nmol/L and T3of Nyala (1.7307 ±â€¯0.96508) nmol/L, the (P-value = 0.153). TSH for Khartoum (1.4480 ±â€¯0.95807)mIU/Land the mean serum TSH of Nyala (1.4553 ±â€¯1.0244) mIU/L, the (P-value = 0.885). The study showed a clear observation of improvement of hypothyroidism cases in Nyala while the ratio decreased from 64.09% to 0.6%. All the results were carried out according to normal range of Sudanese. The conclusion from this study the iodine supplementation programme is successful. The study recommends rising the health awareness among people by explain the severity of iodine deficiency, and continue in iodine supplementation programme, also establishment of monitoring system including monitoring the presence of iodized diets (sugar, salt, oils, and bread) in the markets. Finally, further studies are needed in other parts of Sudan to assess the size of iodine deficiency problem.

Reference Range and Sociodemographic Characteristics of TSH among Reproductive Age Women in Rural China.

Appropriate reference range of thyroid-stimulating hormone (TSH) is important to interpreting the results of thyroid functional tests. However, the reference range and sociodemographic characteristics of TSH based on large-scale studies are yet to be declared in rural China. To clarify reference range and sociodemographic characteristics of TSH in reproductive age of women from rural China. A nationwide population-based study was conducted as The National Free Preconception Health Examination Project (NFPHEP). Nearly 400,000 (n = 392,659) of Chinese rural women aged 15-55 years were randomly recruited. Predetermined strict exclusion criteria made a number of 359,895 as the reference population. Serum TSH was evaluated with enzyme-linked immunosorbent assay (ELISA). The reference range of TSH on overall and reference population was 0.39-5.20 and 0.39-5.13 uIU/ml (2.5th-97.5th percentiles), respectively. In the reference population, the range (2.5th to 97.5th percentile) of serum TSH in different age groups was 0.40-5.03 uIU/ml, 0.39-5.15 uIU/ml, 0.37-6.10 uIU/ml, and 0.44-7.03 uIU/ml, respectively. The mean TSH value in women aged 26-35 years was 2.26 uIU/ml, significantly lower than those aged 36-45 (p < 0.001). The mean TSH values for eastern, central, and western regions were 2.28 uIU/ml, 2.29 uIU/ml, and 2.24 uIU/ml respectively. The mean of serum TSH concentration was significantly higher in central region than that in western region (p ≤ 0.001). The TSH value 0.39-5.13 uIU/ml (2.5th-97.5th percentiles) was derived as a reference range of reproductive age women from rural China. We use the TSH ranges from reference population to diagnose hyperthyrotropinemia or hypothyroidism in different areas in China. The reference ranges for eastern, central, and western regions were 0.33-5.61 uIU/ml, 0.40-5.04 uIU/ml, and 0.40-4.98 uIU/ml (2.5th-97.5th percentiles) respectively. The value of serum TSH was associated with age, living region, smoking, drinking, educational level, and interpersonal tension, as well as life and economic pressure, but irrelevant to ethnicity or occupation.

Assessment of thyroid function, ioduria and oxidative stress in women in the first trimester of pregnancy.

INTRODUCTION: adequate iodine intake during pregnancy is essential for the synthesis of thyroid hormones, which are important for the physiological functions of the mother and appropriate maturation of the central nervous system of the fetus. OBJECTIVE: the objective of the present study was to determine the levels of urinary iodine excretion and thyroid function, antioxidants and oxidative stress markers in pregnant women. METHODS: the study was conducted on 191 pregnant women and 62 non-pregnant women who were evaluated regarding nutritional status. Analyses of urinary iodine, of oxidative stress markers and thyroid function were performed, revealing iodine insufficiency in 81 pregnant women. RESULTS: there was no change in the thyroid stimulating hormone concentration in 89% of the pregnant women. Antithyroperoxidase antibody values were higher in the control group compared to the pregnant women's group (64.5% and 12.6%, respectively) and antithyroglobulin antibody values were also higher in the control group (11.6%). Assessment of oxidative stress revealed higher levels of advanced oxidation protein products, of total antioxidant capacity and of superoxide dismutase antioxidants in pregnant women. Classification of ioduria with respect to oxidative stress markers revealed lower α-tocopherol levels for the pregnant women with iodine insufficiency. CONCLUSION: on this basis, the results suggest that iodine insufficiency did not induce changes in thyroid stimulating hormone levels or antibodies and those pregnant women with adequate urinary iodine excretion had a better profile of the α-tocopherol antioxidant, indicating that iodine may play a significant role in antioxidant capacity during gestation.

Quantitative Assessment of Thyroid, Submandibular, and Parotid Glands Elasticity With Shear-Wave Elastography in Children.

Tissue elasticity is becoming a more commonly used parameter in evaluation of parenchyma in inflammatory diseases. Considering the changes in the thyroid and salivary glands with adolescence, determination of mean elasticity ranges with a function of age is necessary to apply ultrasound elastography more widely in the pediatric population.The thyroid, submandibular, and parotid glands of 127 healthy volunteers (66 males, 61 females; mean age = 10.3 ± 3.9 years; range = 3-17 years) were evaluated with shear-wave elastography.The mean elasticity values for the thyroid, submandibular, and parotid glands were 14.6 ± 3.3, 11.8 ± 2.2, and 11.8 ± 2.6 kPa, respectively. There was a significant positive correlation between age and elasticity of the thyroid, submandibular, and parotid glands. There was a significant correlation between age and elasticity value of the thyroid gland adjusted for weight and height.This study provided the baseline quantitative elasticity measures of thyroid, submandibular, and parotid glands, which would be a reference for upcoming studies. In addition, an increase in elasticity value in thyroid gland as a function of age independent of change in weight and height was demonstrated.

Assessment of thyroid function in children, adults and pregnant and lactating women after long-term salt iodisation measurements.

Universal salt iodisation (USI) has been successfully implemented in China for more than 15 years. Recent evidence suggests that the definition of 'adequate iodine' (100-199 µg/l) be revised to 'sufficient iodine' (100-299 µg/l) based on the median urinary iodine concentration (MUI) in school-age children. The objective of this study was to determine the prevalence of thyroid dysfunction in populations after long-term salt iodisation and examine whether the definition of adequate iodine can be broadened to sufficient iodine based on the thyroid function in four population groups. A cross-sectional survey was conducted in six provinces in the northern, central and southern regions of China. Four population groups consisting of 657 children, 755 adults, 347 pregnant women and 348 lactating women were recruited. Three spot urinary samples were collected over a 10-d period and blood samples were collected on the 1st day. In the study, among the adults, pregnant women and lactating women, the prevalence rates of elevated thyroglobulin antibody and thyroid microsomal antibody levels were 12·4, 8·5 and 7·8 %, and 12·1, 9·1 and 9·1 %, respectively. Abnormally high thyroid dysfunction prevalence was not observed after more than 15 years of USI in China because the thyroid dysfunction rates were all <5 %. The recommended range should be cautiously broadened from adequate iodine to sufficient iodine according to the MUI of school-age children considering the high levels of hormones and antibodies in the other populations. Adults, particularly pregnant women positive for thyroid antibodies, should be closely monitored.

Effect of dietary utilisation of sugarcane press mud on production performance of Muzaffarnagari lambs.

Sugarcane press mud (SPM) is one of the potential agro-industrial by-products available in India and research exploring its utilisation in small ruminant nutrition is scanty. In this direction, the present study evaluated the feasibility of dietary incorporation of SPM at different levels in a feeding trial lasting 180 days. A total of 21 Muzaffarnagari ram lambs were randomly distributed into three groups of seven each based on comparable body weight (11.70 ± 0.29 kg) and age (3-5 months) following a completely randomised design. The three dietary treatments were (1) SP0 (control), concentrate mixture without SPM; (2) SP10, concentrate mixture comprising 10% SPM and (3) SP20, concentrate mixture comprising 20% SPM on air-dry basis. The experimental lambs were offered weighed quantity of designated isonitrogenous (crude protein = 20.6%) and isoenergetic (metabolisable energy = 12.1 MJ/kg) concentrate mixture (coarse mash) and along with ad libitum wheat straw (threshed to 1-2-cm length) and a 9-day metabolism trial was conducted. Results revealed no significant (P > 0.05) differences in intake and digestibility of nutrients, nitrogen balance, nutritive value of diets, average daily gain, as well as feed conversion ratio among three groups. The serum concentration of triiodothyronine and tetraiodothyronine did not differ due to treatments. Likewise, wool yield and its quality, measured in terms of fibre diameter, medullation percentage and staple length were also comparable irrespective of dietary variation. Furthermore, the cost of concentrate mixture (Rs/day) was lower (P ≤ 0.05) in SP20 followed by SP10 as compared to group SP0. These findings suggested that SPM could be safely fed up to 20% level in the concentrate mixture for lambs substituting expensive traditional feed ingredients without negatively inflicting the performance of growing lambs.

Monitoring Thyroid Function in Patients on Levothyroxine. Assessment of Conformity to National Guidance and Variability in Practice.

With demand for endocrine tests steadily increasing year-on-year, we examined thyroid function test (TFT) frequencies in patients on levothyroxine replacement therapy to assess the effect of initial TFT results and request source on TFT re-testing interval. All TFTs performed by the Clinical Biochemistry Departments at the Salford Royal Hospital (2009-2012; 288 263 requests from 139 793 patients) and University Hospital of North Midlands (2011-2014; 579 156 requests from 193 035 patients) were extracted from the laboratory computer systems. Of these, 54 894 tests were on 13 297 patients confirmed to be on levothyroxine therapy in the test cohort (Salford) and 67 298 requests on 11 971 patients in the confirmatory cohort (North Midlands). In the test cohort, median TFT re-testing interval in the total group was 19.1 weeks (IQR 9.1-37.7 weeks), with clearly defined peaks in TFT re-testing evident at 6 and 12 months and a prominent broad peak at 1-3 months. Median re-test interval was much lower than recommended (52 weeks) for those with normal TFTs at 31.3 weeks (30.6 weeks for the confirmatory cohort). Where thyroid-stimulating hormone (TSH) was elevated and free thyroxine (fT4) was below the reference range, re-test interval was much longer than is recommended (8 weeks) at 13.4-17.6 weeks (7.1-23.4 weeks in the confirmatory cohort), as was the interval when TSH was below and fT4 was above the normal range, at 16.7-25.6 weeks (27.5-31.9 weeks in the confirmatory cohort). Our findings show that the majority of TFT requests are requested outside recommended intervals and within-practice variability is high. A new approach to ensuring optimum monitoring frequency is required. Direct requesting from the clinical laboratory may provide one such solution.

Biochemical Testing of the Thyroid: TSH is the Best and, Oftentimes, Only Test Needed - A Review for Primary Care.

Disorders of thyroid function are common, and screening, diagnosis, and management are often performed by primary care providers. While management of significant biochemical abnormalities is reasonably straight forward, laboratory tests only slightly outside, or even within, the normal range are becoming more difficult to appropriately manage. A large part of this increasing difficulty in appropriate management is caused by patients requesting, and even demanding, certain tests or treatments that may not be indicated. Symptoms of thyroid dysfunction are non-specific and extremely prevalent in the general population. This, along with a growing body of information available to patients via the lay press and internet suggesting that traditional thyroid function testing is not reliable, has fostered some degree of patient mistrust. Increasingly, when a physician informs a patient that their thyroid is not the cause of their symptoms, the patient is dissatisfied and even angry. This review aims to clarify the interpretation of normal and mild abnormalities of thyroid function tests by describing pituitary-thyroid physiology and through an in depth review of, arguably, the three most important biochemical tests of thyroid function: TSH, free T4, and anti-TPO antibodies. It is important for primary care providers to have an understanding of the shortcomings and proper interpretation of these tests to be better able to discuss thyroid function with their patients.

Dosimetry at the sub-cellular scale of Auger-electron emitter 99mTc in a mouse single thyroid follicle.

The Auger-electrons emitted by (99m)Tc have been recently associated with the induction of thyroid stunning in in vivo experiments in mice, making the dosimetry at the sub-cellular level of (99m)Tc a pertinent and pressing subject. The S-values for (99m)Tc were calculated using MCNP6, which was first validated for studies at the sub-cellular scale and for low energies electrons. The calculation was then performed for (99m)Tc within different cellular compartments in a single mouse thyroid follicle model, considering the radiative and non-radiative transitions of the (99m)Tc radiation spectrum. It was shown that the contribution of the (99m)Tc Auger and low energy electrons to the absorbed dose to the follicular cells' nucleus is important, being at least of the same order of magnitude compared to the emitted photons' contribution and cannot be neglected. The results suggest that Auger-electrons emitted by (99m)Tc play a significant role in the occurrence of the thyroid stunning effect in mice.

MORPHOLOGICAL ASSESSMENT OF NATIVE MALE SUBJECTS' THYROID BODY IN THE REPUBLIC SAKHA (YAKUTIA) IN DIFFERENT SEASONS.

Morphological analysis of macro-, microstructures of native male subjects' thyroid gland in the Republic Sakha (Yakutia) in different seasons has been conducted. Macromorphometric indicators of native male subjects' thyroid gland (specific weight, total capacity, linear indicators were specified in summer and winter seasons. Micromorphometric characteristics of structural components of native male subjects' thyroid gland tissue was given in relation to different seasons. In this case native male subjects' thyroid gland was as curtained as normoplastic mixed type of structure, indicators of outer and inner thyroid gland follicles diameter in winter period were slightly bigger than in summer period. The same tendency was observed when thyroid gland follicular-colloidal index was calculated. On the data obtained the attempt to assess season temperature factor impact on the thyroid gland structural indicators were made. This assessment might be used as morphological equivalent of the body adaptation processes in northern regions.

Sleep deprivation alters thyroid hormone economy in rats.

NEW FINDINGS: What is the central question of this study? The relationship between the thyroid system and sleep deprivation has seldom been assessed in the literature, and mounting evidence exists that sleep disturbances influence human lifestyles. The aim of this study was to investigate the hypothalamic-pituitary-thyroid axis and thyroid hormone metabolism in sleep-deprived and sleep-restricted rats. What is the main finding and its importance? Central hypothyroidism and high thyroxine (T4 ) to 3,5,3'-triiodothyronine (T3 ) activation in brown adipose tissue were observed following sleep deprivation. Sleep-restricted rats exhibited normal thyroid-stimulating hormone and T4 concentrations despite increased circulating T3 . Sleep recovery for 24 h did not normalize the high T3 concentrations, suggesting that high T3 is a powerful counterregulatory mechanism activated following sleep deprivation. Modern life has shortened sleep time, and the consequences of sleep deprivation have been examined in both human subjects and animal models. As the relationship between thyroid function and sleep deprivation has not been fully investigated, the aim of this study was to assess the hypothalamic-pituitary-thyroid axis and thyroid hormone metabolism following paradoxical sleep deprivation (PSD) and sleep restriction (SR) in rats. The effects of a 24 h rebound period were also studied. Male Wistar rats (200-250 g, n = 10 per group) were subjected to sleep deprivation via the modified multiple platform method. Rats were assigned to the following seven groups: control, PSD for 24 or 96 h, 24 or 96 h of sleep deprivation with rebound (PSD24R and PSD96R), SR for 21 days (SR21) and SR21 with rebound (SR21R). Blood samples were collected to determine the 3,5,3'-triiodothyronine (T3 ), thyroxine (T4 ) and thyroid-stimulating hormone concentrations. Brown adipose tissue iodothyronine deiodinase type 2 (D2) activity was also evaluated. Body weight gain was dramatically reduced (by ∼50-100%) in all sleep-deprived and sleep-restricted rats; rebound restored this parameter in only the PSD24R group. The serum TSH and T4 concentrations decreased, whereas T3 increased in both the PSD24 and PSD96 groups compared with control animals (P < 0.05). Only PSD24R and PSD96R normalized T4 and thyroid-stimulating hormone concentrations, respectively, independently of the higher circulating T3 concentrations (∼20-30%) noted in all groups compared with control animals (P < 0.05). Brown adipose tissue D2 activity increased in the PSD 24 and 96 h groups (∼10 times), and PSD24R was more effective than PSD96R at restoring basal brown adipose tissue D2 activity. Our data suggest that thyroid hormone metabolism adapts to sleep deprivation-induced hypothalamic-pituitary-thyroid alterations and increases T4 to T3 activation peripherally, thereby increasing circulating T3 in rats.

An assessment of iodine nutritional status and thyroid hormone levels in children aged 8-10 years living in Zhejiang Province, China: a cross-sectional study.

UNLABELLED: Iodine is an essential nutrient for the synthesis of thyroid hormones that are critical for brain development. Iodine deficiencies were prevalent in China until the introduction of universal salt iodization (USI) in 1995. USI has been considered as the world's best achievements. This study aims to assess children's iodine nutrition and goiter status in Zhejiang Province in order to provide reasonable suggestions to the government for policy-making under the USI period. A cross-sectional survey in Zhejiang Province was conducted to children aged 8-10 years by stage cluster random sampling method. Spot urine samples were collected and analyzed. Thyroid ultrasonography examination was performed by special trained technicians using a 7.5-MHz transducer. Fasting venous blood samples were collected and analyzed for thyroid functional status. The median urinary iodine concentration was found to be 173.3 µg/L. The percentage of urine samples with iodine concentration <100 µg/L, 100-300 µg/L, and >300 µg/L was 15.5, 42.0, and 13.3 %, respectively. Goiter prevalence rate with iodine concentration <100 µg/L, 100-300 µg/L, and >300 µg/L was 6.8, 10.0, and 14.9 %, respectively, with no significant difference. Children with goiter have lower serum FT3 and T3 concentrations compared to those without goiter (p < 0.05). CONCLUSIONS: The median urinary iodine concentration of children aged 8-10 years falls in optimal iodine status as recommended by WHO/UNICEF/ICCIDD. Maintaining USI at an appropriate level is an important part of preventing iodine deficiency disorders and should always be based on routine monitoring urinary iodine concentration by the province.

Impact of thyroid status and age on comprehensive geriatric assessment.

This study aimed to evaluate the prevalence of thyroid dysfunction in elderly subjects attending an outpatient clinic at a tertiary hospital and to assess whether subclinical hypothyroidism (SCH) or aging affected activities of daily living (ADLs), instrumental activities of daily living (IADLs), cognitive status, or depressive symptoms. This crosssectional study included 411 patients recruited in the outpatient geriatric setting. 48 subjects reported levothyroxine use and were evaluated separately. After excluding subjects with diseases or drugs which could influence thyroid status, the 284 subjects remaining were classified as having euthyroidism (n = 235, 82.8 %), subclinical hypothyroidism (n = 43, 15.1 %), subclinical hyperthyroidism (n = 4, 1.4 %), or overt hyperthyroidism (n = 2, 0.7 %). ADLs and IADLs were assessed using the Katz Index (ranging from 0 [independence] to 6 [dependence in all activities]) and Health Assessment Questionnaire (ranging from 0 to 3 [severely disabled]), respectively. Cognition was assessed using the mini mental state depressive symptoms that were assessed using the Geriatric depression scale or cornell scale for depression in dementia. SCH did not reduce performance in ADLs or IADLs in elderly subjects as a whole, but was an independent protective factor against dependence in ADLs (OR = 0.196 [0.045-0.853]; p = 0.003) and IADLs (OR = 0.060 [0.010-0.361]; p = 0.002) in subjects aged ≥85 years. Very old subjects with SCH showed better performance in ADLs than did those with euthyroidism (Katz Index: 0.9 ± 1.6 [median: 0.5] vs. 1.7 ± 1.7 [1.0], p = 0.024; HAQ: 1.2 ± 0.8 [0.9] vs. 1.8 ± 1.0 [1.9], p = 0.015). This putative protective effect of SCH was not found in subjects aged <85 years. The number of falls, number of medications used, depressive symptoms, and cognitive impairment did not differ among thyroid status groups, regardless of age. In conclusion, SCH does not have impact functional performance in the elderly population as a whole, but was associated with better functional status in subjects aged ≥85 years.

American Thyroid Association Guide to investigating thyroid hormone economy and action in rodent and cell models.

BACKGROUND: An in-depth understanding of the fundamental principles that regulate thyroid hormone homeostasis is critical for the development of new diagnostic and treatment approaches for patients with thyroid disease. SUMMARY: Important clinical practices in use today for the treatment of patients with hypothyroidism, hyperthyroidism, or thyroid cancer are the result of laboratory discoveries made by scientists investigating the most basic aspects of thyroid structure and molecular biology. In this document, a panel of experts commissioned by the American Thyroid Association makes a series of recommendations related to the study of thyroid hormone economy and action. These recommendations are intended to promote standardization of study design, which should in turn increase the comparability and reproducibility of experimental findings. CONCLUSIONS: It is expected that adherence to these recommendations by investigators in the field will facilitate progress towards a better understanding of the thyroid gland and thyroid hormone dependent processes.

Growth as a mirror: is endocrine disruption challenging Tanner's concept?

BACKGROUND: James Tanner coined the expression 'Growth as a Mirror' and summarized in four words the results of more than a century of research on growth. Nineteenth century social reformers saw poor child growth as a reflection of terrible environmental conditions of the working class. Later investigators in anthropology and other fields clarified the connections between poor nutrition, disease, psychosocial stress and poor growth. AIM: To evaluate the growth as a mirror concept in light of recent studies of endocrine disruption. PAPERS AND IMPLICATIONS: Pollution is recognized as a prominent component of the modern environment. From studies of many pollutants it is clear that some pollutants depress growth while others speed sexual maturation and increase growth, primarily in weight and fatness. While such unwelcome environmental features do not always suppress growth, growth still mirrors the environment in all its complexity and this relationship is key to understanding growth patterns today. For example, Akwesasne Mohawk adolescents are characterized by high rates of obesity and overweight. Their growth reflects the multiple intersecting influences of psychosocial stress, several pollutant exposures and limited dietary choices. CONCLUSION: Although Tanner did not anticipate the myriad influences of pollutants, the growth as a mirror concept continues to have great validity and utility.