Prevalence of normal TSH value among patients with autonomously functioning thyroid nodule

BACKGROUND

International guidelines significantly diverge on the effectiveness of thyroid scintigraphy (TS) in the initial work-up of thyroid nodules. In particular, the role of TS to detect or exclude the presence of autonomously functioning thyroid nodules (AFTN) in patients with normal serum thyrotropin (TSH) is still a matter to debate. Here, we aimed to review the literature on the prevalence of normal TSH value among patients with AFTN and meta-analyse data of the retrieved eligible papers.

MATERIALS AND METHODS

A comprehensive literature search of studies published from January 2000 to December 2014 on AFTN detected by TS was performed. Records reporting serum TSH values in AFTN were selected. Pooled prevalence of AFTN with normal TSH values was calculated on a per-patient analysis including 95% confidence intervals (95% CI).

RESULTS

Eight records including 2761 AFTN were selected for the meta-analysis. Pooled prevalence of AFTN with normal TSH detected by TS was 50% (95% CI: 32-68%). Selection bias in the included studies and heterogeneity among studies were potential limitations of the meta-analysis.

CONCLUSIONS

Present meta-analysis shows that about one in two patients with AFTN demonstrated by TS has a TSH value within normal references. As a consequence, TSH measurement may not be considered as effective as a single tool to detect or exclude AFTN, and TS remains mandatory.

Low-normal thyroid function and the pathogenesis of common cardio-metabolic disorders

BACKGROUND

Subclinical hypothyroidism may adversely affect the development of cardiovascular disease (CVD). Less is known about the role of low-normal thyroid function, that is higher thyroid-stimulating hormone and/or lower free thyroxine levels within the euthyroid reference range, in the development of cardio-metabolic disorders. This review is focused on the relationship of low-normal thyroid function with CVD, plasma lipids and lipoprotein function, as well as with metabolic syndrome (MetS), chronic kidney disease (CKD) and nonalcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

This narrative review, which includes results from previously published systematic reviews and meta-analyses, is based on clinical and basic research papers, obtained via MEDLINE and PubMed up to November 2014.

RESULTS

Low-normal thyroid function could adversely affect the development of (subclinical) atherosclerotic manifestations. It is likely that low-normal thyroid function relates to modest increases in plasma total cholesterol, LDL cholesterol and triglycerides, and may convey pro-atherogenic changes in lipoprotein metabolism and in HDL function. Most available data support the concept that low-normal thyroid function is associated with MetS, insulin resistance and CKD, but not with high blood pressure. Inconsistent effects of low-normal thyroid function on NAFLD have been reported so far.

CONCLUSIONS

Observational studies suggest that low-normal thyroid function may be implicated in the pathogenesis of CVD. Low-normal thyroid function could also play a role in the development of MetS, insulin resistance and CKD, but the relationship with NAFLD is uncertain. The extent to which low-normal thyroid function prospectively predicts cardio-metabolic disorders has been insufficiently established so far.

Association between lipids profile and thyroid parameters in euthyroid diabetic subjects: a cross-sectional study

BACKGROUND

The concept is now emerging that higher thyroid-stimulating hormone (TSH) and lower thyroid hormone levels within the euthyroid range may adversely affect atherosclerosis. The aim of this study was to investigate the potential association between thyroid parameters and lipids profile in a cohort of euthyroid diabetic subjects.

METHODS

Four hundred and sixty-two euthyroid type 2 diabetes subjects (302 males and 160 females) were consecutively recruited. Clinical and anthropometric data was collected from all participants. Whole blood samples were drawn in the morning after an overnight fasting for the measurement of serum TSH, free thyroxine (FT4), free triiothyronine (FT3), anti-thyroid peroxidase antibody (TPO-Ab) levels, as well as lipid concentrations and glucose.

RESULTS

TSH was higher in females than males. Stratified by TSH, high-density lipoprotein cholesterol (HDL-c) level increased in subjects with TSH ≥2.5uIU/mL (P = 0.004). And TSH was associated with HDL-c in a Pearson correlation test, however, the association failed to attain significance in partial correlation analyses, adjusted for age, sex, duration of diabetes, fasting glucose and BMI. In females, total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) level was significant lower in subjects with TSH <2.5uIU/mL. TSH was significantly associated with TC and LDL-c, even in a partial correlation analysis (P = 0.006 and 0.011, respectively). In a multiple linear regression analysis (stepwise), TSH was positive associated with TC (β = 0.202, P = 0.005) and LDL-c (β = 0.144, P = 0.010). In one hundred and six patients having TPO antibody assays, 6 (5.66%) were positive. The blood pressure and lipid levels were lower in TPO-Ab positive patients, however, the differences were not significantly.

CONCLUSIONS

In conclusion, we identified TSH was positively associated with serum TC and LDL-c in euthyroid diabetic women. Our analysis in the subgroup having TPO antibody assays demonstrating non-significantly lower TC levels among seropositive subjects was consistent with the above stated consideration for women as a whole. Further investigations are needed to understand the intimate mechanisms of lipid metabolism in type 2 diabetes with respect to thyroid function.

Proteomic Analysis of Human Pluripotent Stem Cell-Derived, Fetal, and Adult Ventricular Cardiomyocytes Reveals Pathways Crucial for Cardiac Metabolism and Maturation

BACKGROUND

Differentiation of pluripotent human embryonic stem cells (hESCs) to the cardiac lineage represents a potentially unlimited source of ventricular cardiomyocytes (VCMs), but hESC-VCMs are developmentally immature. Previous attempts to profile hESC-VCMs primarily relied on transcriptomic approaches, but the global proteome has not been examined. Furthermore, most hESC-CM studies focus on pathways important for cardiac differentiation, rather than regulatory mechanisms for CM maturation. We hypothesized that gene products and pathways crucial for maturation can be identified by comparing the proteomes of hESCs, hESC-derived VCMs, human fetal and human adult ventricular and atrial CMs.

METHODS AND RESULTS

Using two-dimensional-differential-in-gel electrophoresis, 121 differentially expressed (>1.5-fold; P<0.05) proteins were detected. The data set implicated a role of the peroxisome proliferator-activated receptor α signaling in cardiac maturation. Consistently, WY-14643, a peroxisome proliferator-activated receptor α agonist, increased fatty oxidative enzyme level, hyperpolarized mitochondrial membrane potential and induced a more organized morphology. Along this line, treatment with the thyroid hormone triiodothyronine increased the dynamic tension developed in engineered human ventricular cardiac microtissue by 3-fold, signifying their maturation.

CONCLUSIONS

We conclude that the peroxisome proliferator-activated receptor α and thyroid hormone pathways modulate the metabolism and maturation of hESC-VCMs and their engineered tissue constructs. These results may lead to mechanism-based methods for deriving mature chamber-specific CMs.

Thyroid Function/Antibodies in Sudanese Patients with Preeclampsia

Preeclampsia is an important cause of maternal and prenatal morbidity and mortality in the developing countries. Changes in thyroid function/antibodies profiles in preeclamptic women are controversial and were never investigated before in Sudan. A case-control study was conducted at Medani Hospital, Sudan, to investigate thyroid function/antibodies in preeclampsia. The sociodemographic, medical history was gathered using questionnaires. Thyroid hormones [thyroid-stimulating hormone (TSH), free tri-iodothyronine (T3), and free thyroxine (T4)] and anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies were measured using ELISA. The three groups [controls, mild, and severe preeclampsia (SP) (55 women in each arm)] were matched in age and parity. While median (interquartile range) of TSH was significantly lower, both free T3 and free T4 levels were significantly higher in women with preeclampsia than in the healthy controls. There was no significant difference in the TSH levels in women with MP and SP. In comparison with women with MP, women with SP had significantly higher levels of free T3 and significantly lower levels of free T4. While anti-TPO antibodies were significantly higher, anti-TG antibodies were significantly lower in women with preeclampsia. Likewise, anti-TPO antibodies were significantly higher and anti-TG antibodies were significantly lower in women with SP than in women with MP. In linear regression, preeclampsia was significantly associated with TSH (-0.675 IU/ml, P = 0.009), free T3 (0.977 pg/ml, P < 0.001), and free T4 (0.186 ng/dl, P < 0.001) levels. In contrast to anti-TG antibodies and TSH, Sudanese patients with preeclampsia had higher levels of T3 and T4 hormones and anti-TPO antibodies irrespective of parity, gestational age, and hemoglobin levels.

Structure-function relationships of glycoprotein hormones and their subunits' ancestors

Glycoprotein hormones (GPHs) are the most complex molecules with hormonal activity. They exist only in vertebrates but the genes encoding their subunits' ancestors are found in most vertebrate and invertebrate species although their roles are still unknown. In the present report, we review the available structural and functional data concerning GPHs and their subunits' ancestors.

Discovery and Development of Small Molecule Allosteric Modulators of Glycoprotein Hormone Receptors

Glycoprotein hormones, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and thyroid-stimulating hormone (TSH) are heterodimeric proteins with a common α-subunit and hormone-specific β-subunit. These hormones are dominant regulators of reproduction and metabolic processes. Receptors for the glycoprotein hormones belong to the family of G protein-coupled receptors. FSH receptor (FSHR) and LH receptor are primarily expressed in somatic cells in ovary and testis to promote egg and sperm production in women and men, respectively. TSH receptor is expressed in thyroid cells and regulates the secretion of T3 and T4. Glycoprotein hormones bind to the large extracellular domain of the receptor and cause a conformational change in the receptor that leads to activation of more than one intracellular signaling pathway. Several small molecules have been described to activate/inhibit glycoprotein hormone receptors through allosteric sites of the receptor. Small molecule allosteric modulators have the potential to be administered orally to patients, thus improving the convenience of treatment. It has been a challenge to develop a small molecule allosteric agonist for glycoprotein hormones that can mimic the agonistic effects of the large natural ligand to activate similar signaling pathways. However, in the past few years, there have been several promising reports describing distinct chemical series with improved potency in preclinical models. In parallel, proposal of new structural model for FSHR and in silico docking studies of small molecule ligands to glycoprotein hormone receptors provide a giant leap on the understanding of the mechanism of action of the natural ligands and new chemical entities on the receptors. This review will focus on the current status of small molecule allosteric modulators of glycoprotein hormone receptors, their effects on common signaling pathways in cells, their utility for clinical application as demonstrated in preclinical models, and use of these molecules as novel tools to dissect the molecular signaling pathways of these receptors.

Mean platelet volume is significantly associated with serum levels of thyroid-stimulating hormone in a cohort of older euthyroid subjects

PURPOSE

This retrospective and observational study aimed to establish whether any relationship exists between the values of serum thyroid-stimulating hormone (TSH) and those of the mean platelet volume (MPV) in a large cohort of older euthyroid Italian subjects.

MATERIALS AND METHOD

The study population was represented by a cohort of 1,050 ostensibly healthy and euthyroid patients aged 50 years and older, who were referred for screening of thyroid disorders over a 1-year period.

RESULTS

A significant association was found between MPV and TSH values in both simple (r = 0.12; p < 0.001) and multivariable regression analysis (beta coefficient, 0.07; p < 0.001) after adjustment for age, sex, free thyroxin values and platelet count. After stratification of the study population according to quartiles of serum TSH levels, a graded increase of MPV values was found from the first to the fourth quartile of TSH (p = 0.013). The odds ratio for an increased MPV value of the fourth versus the first quartile of TSH was 1.54 (95% CI, 1.08-2.20; p = 0.017).

CONCLUSIONS

The results of this investigation demonstrate that a significant, positive and independent association exists between MPV and serum TSH values in a large cohort of older euthyroid Italian subjects.

Association between serum free thyroxine (FT4) and uric acid levels in populations without overt thyroid dysfunction

In this study, we investigated the relationship between thyroid function and serum uric acid (UA) levels in subjects without overt thyroid dysfunction. A total of 6,085 patients were included in this cross-sectional study. Free thyroxine (FT4) levels were positively and linearly associated with serum UA levels (p<0.001), even after adjusting for age, thyroid-stimulating hormone, renal function, and other metabolic components (B 37.13; 95%CI 25.99-48.28; p<0.001). Furthermore, quartile analysis indicated that the prevalence of hyperuricemia was significantly elevated with increasing FT4 levels (quartile II: OR 1.232, 95%CI 1.022-1.486, p=0.029; quartile III: OR 1.234, 95%CI 1.025-1.486, p=0.026; quartile IV: OR 1.409, 95%CI 1.168-1.701, p<0.001). In summary, FT4 is linearly associated with serum UA levels in subjects lacking clinical thyroid dysfunction, and the prevalence of hyperuricemia is elevated with increasing FT4 levels.

Altered thyroid hormone profile in offspring after exposure to high estradiol environment during the first trimester of pregnancy: a cross-sectional study

BACKGROUND

The increasing number of babies conceived by in vitro fertilization and embryo transfer (IVF-ET) shifts concern from pregnancy outcomes to long-time health of offspring. Maternal high estradiol (E2) is a major characteristic of IVF-ET and lasts throughout the first trimester of pregnancy. The fetal thyroid develops during this period and may thus be affected by exposure to the supra-physiological E2. The aim of this study is to investigate whether the high E2 maternal environment in the first trimester increases the risk of thyroid dysfunction in children born following IVF-ET.

METHODS

A cross-sectional survey design was used to carry out face-to-face interviews with consecutive children attending the hospital. A total of 949 singletons born after fresh embryo transfer (ET) (n=357), frozen ET (n=212), and natural conception (NC) (n=380), aged 3 to 10 years old, were included. All children were thoroughly examined. Meanwhile, another 183 newborns, including 55 fresh ET, 48 frozen ET, and 80 NC were studied. Levels of serum T3, FT3, T4, FT4, and TSH and levels of maternal E2 at different stages of the first trimester were examined.

RESULTS

The mean serum E2 levels of women undergoing fresh ET during the first trimester of pregnancy were significantly higher than those of the women undergoing frozen ET or following NC. The thyroid hormone profile, especially the levels of T4, FT4, and TSH, were significantly increased in 3- to 10-year-old children conceived by fresh ET compared to NC. The same tendency was confirmed in newborns. However, levels of T4 and TSH in the frozen ET group were nearer to that of the NC group. Furthermore, levels of T4 and FT4 in fresh ET were positively correlated with maternal serum levels of E2 during early pregnancy.

CONCLUSIONS

The maternal high E2 environment in the first trimester is correlated with increased risk of thyroid dysfunction. Frozen ET could reduce risks of thyroid damage in children conceived by IVF. Further studies are needed to confirm these findings and to better determine the underlying molecular mechanisms and clinical significance.

TRIAL REGISTRATION

ChicCTR-OCC-14004682 (22-05-2014).

On the role of gallbladder emptying and incretin hormones for nutrient-mediated TSH suppression in patients with type 2 diabetes

Bile acids are possible candidate agents in newly identified pathways through which energy expenditure may be regulated. Preclinical studies suggest that bile acids activate the enzyme type 2 iodothyronine deiodinase, which deiodinates thyroxine (T4) to the biologically active triiodothyronine (T3). We aimed to evaluate the influence of bile acid exposure and incretin hormones on thyroid function parameters in patients with type 2 diabetes. Thyroid-stimulating hormone (TSH) and thyroid hormones (total T3 and free T4) were measured in plasma from two human studies: i) 75 g-oral glucose tolerance test (OGTT) and three isocaloric (500 kcal) and isovolaemic (350 ml) liquid meals with increasing fat content with concomitant ultrasonographic evaluation of gallbladder emptying in 15 patients with type 2 diabetes and 15 healthy age, gender and BMI-matched controls (meal-study) and ii) 50 g-OGTT and isoglycaemic intravenous glucose infusions (IIGI) alone or in combination with glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP1) and/or GLP2, in ten patients with type 2 diabetes (IIGI-study). In both studies, TSH levels declined (P<0.01) similarly following all meal and infusion stimuli. T3 and T4 concentrations did not change in response to any of the applied stimuli. TSH levels declined independently of the degree of gallbladder emptying (meal-study), route of nutrient administration and infusion of gut hormones. In conclusion, intestinal bile flow and i.v. infusions of the gut hormones, GIP, GLP1 and/or GLP2, do not seem to affect thyroid function parameters. Thus, the presence of a 'gut-thyroid-pituitary' axis seems questionable.

Cardiovascular Risk in Patients with Subclinical Hypothyroidism

Subclinical hypothyroidism (SCH) has been associated with increased cardiovascular mortality due to adverse effects mainly on lipids and blood pressure (BP). There is evidence that SCH, especially in patients with thyroid-stimulating hormone (TSH) >10mU/l, may increase cardiovascular risk. Some uncertainty exists regarding the association of SCH with BP; however, that the coexistence of SCH with BP and hypercholesterolaemia has a negative cardiovascular impact is beyond doubt. Insulin resistance, by modulating various risk factors including coagulation, may potentially increase cardiovascular risk. Periodic health examinations including screening has been advised in patients >35 years of age, while treatment with thyroxine should be tailored to each patient.

High levels of procoagulant factors mediate the association between free thyroxine and the risk of venous thrombosis: the MEGA study

BACKGROUND

Thyroid hormone affects the coagulation system, but its effect on clinical disease is not clear. We determined the associations of levels of free thyroxine (FT4), thyroid-stimulating hormone (TSH) and anti-thyroid peroxidase antibodies (antiTPO) with levels of coagulation factors and the risk of venous thrombosis.

METHODS

In a large population based case-control study (Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis study) on the etiology of venous thrombosis, we determined the levels of FT4, TSH, antiTPO, factor FII, FVII, FVIII, FIX, FX, von Willebrand factor (VWF), antithrombin, protein C, protein S and fibrinogen in 2177 cases and 2826 controls.

RESULTS

High levels of FT4 were associated with increased concentrations of procoagulant factors, and not with levels of anticoagulant factors. High levels of FT4 were also associated with the risk of venous thrombosis, up to an odds ratio (OR) of 2.2 (95% confidence interval [CI] 1.0-4.6) for levels above 24.4 pm relative to FT4 levels between 15.5 and 18.9 pm. In 11 cases and one control, clinical hyperthyroidism had been diagnosed within a year of the thrombotic event, leading to an OR of 17.0 (95% CI 2.2-133.0) for thrombosis. The ORs approached unity after adjustment for FVIII and VWF, which suggests that the effect was mediated by these factors. Low TSH levels were also, but less evidently, associated with thrombosis, whereas there was no association between antiTPO and venous thrombosis risk.

CONCLUSIONS

High levels of FT4 increase the concentrations of the procoagulant proteins FVIII, FIX, fibrinogen, and VWF, and by this mechanism increase the risk of venous thrombosis.

Universality and diversity in the signal transduction pathway that regulates seasonal reproduction in vertebrates

Most vertebrates living outside the tropical zone show robust physiological responses in response to seasonal changes in photoperiod, such as seasonal reproduction, molt, and migration. The highly sophisticated photoperiodic mechanism in Japanese quail has been used to uncover the mechanism of seasonal reproduction. Molecular analysis of quail mediobasal hypothalamus (MBH) revealed that local thyroid hormone activation within the MBH plays a critical role in the photoperiodic response of gonads. This activation is accomplished by two gene switches: thyroid hormone-activating (DIO2) and thyroid hormone-inactivating enzymes (DIO3). Functional genomics studies have shown that long-day induced thyroid-stimulating hormone (TSH) in the pars tuberalis (PT) of the pituitary gland regulates DIO2/3 switching. In birds, light information received directly by deep brain photoreceptors regulates PT TSH. Recent studies demonstrated that Opsin 5-positive cerebrospinal fluid (CSF)-contacting neurons are deep brain photoreceptors that regulate avian seasonal reproduction. Although the involvement of TSH and DIO2/3 in seasonal reproduction has been confirmed in various mammals, the light input pathway that regulates PT TSH in mammals differs from that of birds. In mammals, the eye is the only photoreceptor organ and light information received by the eye is transmitted to the pineal gland through the circadian pacemaker, the suprachiasmatic nucleus. Nocturnal melatonin secretion from the pineal gland indicates the length of night and regulates the PT TSH. In fish, the regulatory machinery for seasonal reproduction, from light input to neuroendocrine output, has been recently demonstrated in the coronet cells of the saccus vasculosus (SV). The SV is unique to fish and coronet cells are CSF-contacting neurons. Here, we discuss the universality and diversity of signal transduction pathways that regulate vertebrate seasonal reproduction.

Effects of TSH on the function of human umbilical vein endothelial cells

Recent studies have reported that subclinical hypothyroidism (SCH) is associated with atherosclerosis (AS). Thyroid hormone is maintained at normal levels in patients with SCH, whereas TSH is increased. However, the pathogenesis of AS in association with SCH is only partially understood. In addition, endothelial dysfunction plays an important role in the development of AS. The purpose of the present research was to study the direct effect of TSH on human umbilical vein endothelial cells (HUVECs). The expression of some genes associated with endothelial dysfunction after treatment with TSH was evaluated by real-time PCR and western blotting respectively. At first, we showed that the TSH receptor (TSHR) is expressed in HUVECs. We also provide evidence indicating that TSH treatment promotes tumor necrosis factor α-induced endothelial cells interactions by upregulating the expression of the adhesion molecules intercellular adhesion molecule-1. Furthermore, the expression of endothelial nitric oxide synthase (eNOS) and prostacyclin (PGI₂) was significantly attenuated following treatment with TSH in dose- and time-dependent manner. Conversely, the results indicated that TSH upregulated endothelin-1 (ET1) mRNA and protein expression in HUVECs, similar effects were observed for plasminogen activator inhibitor-1 (PAI1) after treatment with various concentrations of TSH. Taken together, these results demonstrate that elevated TSH can promote endothelial dysfunction by altering gene expression in HUVECs.

The role of scintigraphy and ultrasound in the imaging of neonatal hypothyroidism: 5-year retrospective review of single-centre experience

INTRODUCTION

Congenital hypothyroidism (CH), as indicated by an elevation of capillary thyroid-stimulating hormone (TSH) at newborn screening, is a preventable cause of mental retardation with varying aetiology; it can be transient or permanent. Radionuclide assessment is currently the gold standard for imaging CH. This study aimed to (i) review the different scintigraphic patterns and correlate them with TSH levels/patient outcomes, (ii) assess the role of sonography in neonates with apparent agenesis as indicated by scintigraphy and (iii) develop a diagnostic investigative algorithm.

METHODS

The technetium thyroid scans of 83 consecutive patients (49 females, average age 32 days) with CH scanned between 2005 and 2009 were retrospectively reviewed. Two nuclear medicine physicians blinded to the clinical details interpreted the scans in consensus. Scintigram appearances were categorised into five groups. Patients scintigraphically diagnosed with thyroid agenesis were evaluated with ultrasound. TSH values and scintigraphic and sonographic findings were correlated with patients' final diagnosis.

RESULTS

Based on scintigraphy, 14, 13 and 19 patients out of 83 were assessed as having normal thyroid sites with normal, increased and decreased uptake, respectively. Twenty-two of 83 patients had no uptake, and 15 of 83 patients had ectopic uptake. Higher median TSH levels were seen in no-uptake and ectopic uptake subgroups. Eighteen of 22 patients with no uptake were evaluated with ultrasound. Three of the 18 patients had a normal thyroid gland, and three of 18 patients had a hypoplastic thyroid.

CONCLUSION

Scintigram findings in patients with congenital hypothyroidism fall into five major categories, which have therapeutic implications (lifelong thyroxine in agenesis versus trial of stopping thyroxine in other subgroups). Sonographic demonstration of thyroid tissue in patients scintigraphically diagnosed with thyroid agenesis has major management implications.

Congenital hypothyroidism in neonates

CONTEXT

Congenital hypothyroidism (CH) is one of the most common preventable causes of mental retardation in children and it occurs in approximately 1:2,000-1:4,000 newborns.

AIMS AND OBJECTIVES

The aim of this study is to determine the frequency of CH in neonates.

SETTINGS AND DESIGN

This cross-sectional study was conducted in neonatal units of the Department of Pediatrics Unit-I, King Edward Medical University/Mayo Hospital, Lahore and Lady Willington Hospital Lahore in 6 months (January-June 2011).

MATERIALS AND METHODS

Sample was collected by non-probability purposive sampling. After consent, 550 newborn were registered for the study. Demographic data and relevant history was recorded. After aseptic measures, 2-3 ml venous blood analyzed for thyroid-stimulating hormone (TSH) level by immunoradiometric assay. Treatment was started according to the individual merit as per protocol.

STATISTICAL ANALYSIS USED

Data was analyzed by SPSS 17 and Chi-square test was applied to find out the association of CH with different variables.

RESULTS

The study population consisted of 550 newborns. Among 550 newborns, 4 (0.8%) newborns had elevated TSH level. CH had statistically significant association with mother's hypothyroidism (P value 0.000) and mother's drug intake during the pregnancy period (P value 0.013).

CONCLUSION

CH is 0.8% in neonates. It has statistically significant association with mother's hypothyroidism and mother's drug intake during pregnancy.

Dim light at night disrupts the short-day response in Siberian hamsters

Photoperiodic regulation of physiology, morphology, and behavior is crucial for many animals to survive seasonally variable conditions unfavorable for reproduction and survival. The photoperiodic response in mammals is mediated by nocturnal secretion of melatonin under the control of a circadian clock. However, artificial light at night caused by recent urbanization may disrupt the circadian clock, as well as the photoperiodic response by blunting melatonin secretion. Here we examined the effect of dim light at night (dLAN) (5lux of light during the dark phase) on locomotor activity rhythms and short-day regulation of reproduction, body mass, pelage properties, and immune responses of male Siberian hamsters. Short-day animals reduced gonadal and body mass, decreased spermatid nuclei and sperm numbers, molted to a whiter pelage, and increased pelage density compared to long-day animals. However, animals that experienced short days with dLAN did not show these short-day responses. Moreover, short-day specific immune responses were altered in dLAN conditions. The nocturnal activity pattern was blunted in dLAN hamsters, consistent with the observation that dLAN changed expression of the circadian clock gene, Period1. In addition, we demonstrated that expression levels of genes implicated in the photoperiodic response, Mel-1a melatonin receptor, Eyes absent 3, thyroid stimulating hormone receptor, gonadotropin-releasing hormone, and gonadotropin-inhibitory hormone, were higher in dLAN animals than those in short-day animals. These results suggest that dLAN disturbs the circadian clock function and affects the molecular mechanisms of the photoperiodic response.

The impact of thyroid autoimmunity on arterial stiffness in postmenopausal patients with fibromyalgia

OBJECTIVE

The exact mechanism of arterial stiffness in fibromyalgia (FM) remains unclear. The present study aimed to evaluate the association between thyroid function and markers of arterial function in postmenopausal FM patients.

METHODS

This study included 163 postmenopausal FM patients without any known cardiovascular diseases and within a normal reference range of thyroid-stimulating hormone (TSH) level. Clinical parameters including the Fibromyalgia Impact Questionnaire (FIQ), the pain visual analogical scale (VAS) and tender point counts were measured. Vascular function was assessed by brachial-ankle pulse wave velocity (baPWV) and flow-mediated dilation (FMD). We evaluated the associations between arterial markers and serum TSH, free thyroxin, as well as serum thyroidperoxidase autoantibody (TPO Ab).

RESULTS

Patients with a high baPWV (≥ 1490 cm/s) showed more positive TPO Ab (65% vs. 10%, P = 0.006) than those with a normal baPWV. Additionally, the baPWV values of patients with positive TPO Ab were significantly different from those with negative TPO Ab. Age, FIQ and TPO Ab were significantly correlated with baPWV and FMD (all P < 0.05). Multiple linear regression analysis revealed that the only significant predictors of baPWV were age, FIQ and the presence of TPO Ab after adjustment for traditional risk factors. A significant association was also found between FMD and positive TPO Ab.

CONCLUSION

Age, functional status and presence of TPO Ab were significantly associated with increased arterial stiffness in postmenopausal FM patients. Given the combined thyroid autoimmunity in FM patients, a re-evaluation of the effects on the vasculature may be necessary.

The relation between serum and filter paper TSH level in neonates with congenital hypothyroidism

Background:

the aim of this study was to determine the relation between serum and filter paper thyroid-stimulating hormone (TSH) levels in neonates with congenital hypothyroidism (CH). We also tried to determine an appropriate cutoff point of filter TSH for recalling screened neonates.

Materials and Methods:

in this descriptive-analytic study, records of 2283 neonates who had been recalled during CH screening program in Isfahan (Iran) were studied. The relation between serum and filter paper TSH levels in the studied neonates was assessed and the best cutoff point of filter TSH and its sensitivity and specificity for proper diagnosis of CH were determined.

Results:

among the studied neonates, 103 (4.5%) were diagnosed with CH. Using receiver operating characteristic (ROC) curve, the best cutoff point for diagnosing CH was 7.5 with a sensitivity of 74.8% and specificity of 71.3%. The rates of false positive and false negative diagnoses at this cutoff point were28.7% and 25.2%, respectively. There was a significant relationship between serum and filter paper TSH levels.

Conclusion:

the cutoff point for recall should be changed to 7.5 for appropriate screening outcome. On the other hand, considering the low cost of filter paper and importance of missing any case of CH, changing the cutoff point is not necessary. However, further studies in different parts of Iran are required to obtain more accurate results and consider all related factors.

Polymorphisms of endothelin 1 (G5665T and T-1370G) and endothelin receptor type A (C+70G and G-231A) in Graves' disease

PURPOSE

Endothelin 1 (EDN1) is a strong angiogenic and mitogenic factor, playing a key role in hypervascularization, thyroid follicle cell hyperplasia, and lymphocyte infiltration in the thyroid gland of patients with Graves' disease (GD). EDN1 induces angiogenesis and mitogenesis via endothelin receptor type A (EDNRA). This study examined the possible association of EDN1 (G5665T and T-1370G) and EDNRA (C+70G and G-231A) single nucleotide polymorphisms (SNPs) with the occurrence of GD, and evaluates the relationship between genotypes and clinical/laboratory manifestations of GD.

MATERIALS AND METHODS

We analyzed genotype and allele distributions of EDN1 and EDNRA polymorphisms in 165 patients with GD and 181 healthy controls by real-time PCR combined with melting curve analysis.

RESULTS

No significant associations between GD and variant alleles of the studied polymorphisms were observed. However, the anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) levels in EDN1 G5665T GG genotype were higher than those in T allele carriers (GT+TT) (p=0.001 and p=0.026, respectively). In addition, anti-TPO levels in EDN1 T-1370G wild-type homozygous patients were found to be higher than in mutant gene carrying patients (GT+GG) (p=0.006). The presence of EDNRA+70G allele was associated with 3.37-fold increased risk for development of ophthalmopathy in GD patients (p=0.009).

CONCLUSION

Although there were no associations between EDN1 (G5665T and T-1370G) and EDNRA (C+70G and G-231A) SNPs and susceptibility to GD, EDN1 G5665T and T-1370G polymorphisms were related to alterations of autoantibody production and EDNRA C+70G polymorphism is related with increased risk for ophthalmopathy in GD patients.

Association between high-normal levels of alanine aminotransferase and risk factors for atherogenesis

BACKGROUND & AIMS

Liver disease has been associated with cardiovascular disorders, but little is known about the relationship between serum levels of alanine aminotransferase (ALT) and markers of atherogenesis. We investigated the relationship between low-normal and high-normal levels of ALT and an extended panel of cardiovascular risk factors among individuals with no known diseases in a primary care setting.

METHODS

We performed a retrospective analysis of data collected from 6442 asymptomatic patients at wellness visits to a primary care setting in central Virginia from 2010 through 2011. Serum levels of ALT were compared with levels of lipids and lipoproteins, as well as metabolic, inflammatory, and coagulation-related factors associated with risk for cardiovascular disease.

RESULTS

Serum levels of ALT were higher than 40 IU/L in 12% of subjects, and in the high-normal range (19-40 IU/L in women and 31-40 IU/L in men) in 25% of subjects. ALT level was associated with the apolipoprotein B level, concentration and particle size of very-low-density lipoproteins, concentration of low-density lipoprotein (LDL) particles (LDL-P), and percentages of small dense LDL (sdLDL) and sdLDL-cholesterol (sdLDL-C) (P < .0001 for all). A high-normal level of ALT was associated with higher levels of LDL-C, LDL-P, sdLDL-C, and sdLDL particles (P < .001 for all). These effects were independent of age, body mass index, and hyperinsulinemia. Increasing levels of ALT and fasting hyperinsulinemia (>12 μU/mL) synergized with increasing levels of triglycerides, very-low-density lipoprotein particles, LDL-P, sdLDL-C, and percentage of sdLDL-C. Levels of APOA1, high-density lipoprotein-cholesterol, and high-density lipoprotein-class 2 were associated inversely with serum level of ALT (P < .0001 for all).

CONCLUSIONS

In an analysis of asymptomatic individuals, increased serum levels of ALT (even high-normal levels) are associated with markers of cardiovascular disease.

Neuromedin U partly mimics thyroid-stimulating hormone and triggers Wnt/β-catenin signalling in the photoperiodic response of F344 rats

In seasonal animals, photoperiod exerts profound effects on physiology, such as growth, energy balance and reproduction, via changes in the neuroendocrine axes. A key element of the photoperiodic response is the thyroid hormone level in the hypothalamus, which is controlled via retrograde transport of thyroid-stimulating hormone (TSH) from the pars tuberalis of the pituitary. TSH regulates type II deiodinase (Dio2) expression, which transforms inactive thyroid hormone to its active form, via TSH receptors expressed in the ependymal cells of the hypothalamus. In the present study, we hypothesised that a second peptide hormone, neuromedin U (NMU), may play a role in the photoperiodic response alongside TSH because the gene for NMU is also expressed in a strongly photoperiod-dependent manner in the pars tuberalis and its receptor NMU2 is expressed in the ependymal layer of the third ventricle in photoperiod-sensitive F344 rats. Consistent with other studies conducted in nonseasonal mammals, we found that acute i.c.v. injections of NMU into the hypothalamus negatively regulated food intake and body weight and increased core body temperature in F344 rats. At the same time, NMU increased Dio2 mRNA expression in the ependymal region of the hypothalamus similar to the effects of TSH. These data suggest that NMU may affect acute and photoperiodically controlled energy balance through distinct pathways. We also showed that TSH inhibits the expression of type III deiodinase (Dio3) in F344 rats, a response not mimicked by NMU. Furthermore, NMU also increased the expression of genes from the Wnt/β-catenin pathway within the ependymal layer of the third ventricle. This effect was not influenced by TSH. These data indicate that, although NMU acts with some similarities to TSH, it also has completely distinct signalling functions that do not overlap. In summary, the present study of NMU signalling reveals the potential for a new player in the control of seasonal biology.

A novel heterozygous SOX2 mutation causing congenital bilateral anophthalmia, hypogonadotropic hypogonadism and growth hormone deficiency

Heterozygous de novo mutations in SOX2 have been reported in approximately 10-20% of patients with unilateral or bilateral anophthalmia or microphthalmia. An additional phenotype of hypopituitarism, with anterior pituitary hypoplasia and hypogonadotropic hypogonadism, has been reported in patients carrying SOX2 alterations. We report a novel heterozygous mutation in the SOX2 gene in a male affected with congenital bilateral anophthalmia, hypogonadotrophic hypogonadism and growth hormone deficiency. The mutation we describe is a cytosine deletion in position 905 (c905delC) which causes frameshift and an aberrant C-terminal domain. Our report highlights the fact that subjects affected with eye anomalies and harboring SOX2 mutations are at high risk for gonadotropin deficiency, which has important implications for their clinical management.

Depression and alterations in hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axis function in male abstinent methamphetamine abusers

The present study was to investigate depression and alterations in the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-thyroid (HPT) axis function in methamphetamine (METH) abusers after abstinence. Depression was assessed using the 13-item Beck Depression Inventory (BDI-13) scale; blood samples from in-patients who were METH abusers and age-matched and sex-matched healthy controls were collected. The demographic characteristics and history of METH abuse also was assessed. We found that serum levels of adrenocorticotropic hormone (ACTH) and thyroxine were increased; and serum levels of cortisol, triiodothyronine, and thyroid-stimulating hormone were decreased; and the BDI score was higher in METH abusers compared with control. In addition, there was no correlation between the BDI-13 score and any of hormones of HPA and HPT axis was found. Particularly, we found abnormally higher ACTH level and mismatched with lower cortisol level in abstinent METH abusers. These results indicate that METH abusers and that their HPA and HPT functions are all altered after abstinence. Chronically using METH may destroy the regulatory function of the HPA axis, especially the feedback regulation of cortisol to ACTH.