Normal Thyroid-stimulating Hormone Levels Research Articles

Letter to the Editor Report of surgical correction of a cervicovaginal agenesis case: cervicovaginal reconstruction with pudendal thigh flaps

Letter to the Editor Report of surgical correction of a cervicovaginal agenesis case: cervicovaginal reconstruction with pudendal thigh flaps

Increased prevalence of subclinical hypothyroidism in females in mountainous valley of Kashmir

Background:Iodine-rich diet is necessary for proper thyroid gland function. Subclinical hypothyroidism (SCH) is associated with serious complications. Substantial numbers of patients have risk of SCH getting converted into primary hypothyroidism.Objectives:The objectives of the present study are to survey dietary iodine intake pattern in ethnic population of Kashmir and to study the prevalence of SCH.Materials and Methods:A retrospective, cross-sectional referral hospital study was conducted. Sample size comprised of 2550 patients who were referred to Department of Biochemistry, Government Medical college, Srinagar diagnostic laboratory from OPD and IPD of associated SMHS hospital. Assessment of thyroid function over a period of one year from March 2010 to March 2011 in the serum has been performed by electro-chemiluminescence immunoassay method on ECLIA 2010 fully automatic analyzer. Interview cum questionnaire methods were used to record the patient history and dietary iodine intake pattern. Iodine status of these patients was assessed by measuring urinary iodine excretion.Results:Total patients were 2550 comprising of 44.6% males and 56.4% females. Subjects with elevated and normal thyroid stimulating hormone (TSH) levels in the serum were 30.51 and 69.4% respectively. About 550 patients (21.56%) had subclinical hypothyroidism which includes both males and females. Prevalence of SCH was more in females (81.8%) than in males (18.2%). Most of the patients presenting with SCH were in the age group of 20–65 years.Conclusion:The percentage of SCH amongst the study sample patients was 21.56%, which is much higher as compared to other parts of the world. The highest percentage of SCH was found in females (81.8%) as compared to males (18.2%). On the basis of the present study, we suggest that routine screening of selected populations, especially women between 20 and 65 years of age, may be advocated. Further community level awareness programs need to be organized wherein people in mountainous valley of Kashmir are motivated to take salt in iodized form and diet rich in iodine to ensure proper thyroid gland functioning.

Thyroid dysfunctions of prematurity and their impacts on neurodevelopmental outcome1)

Thyroid dysfunction is very common and is associated with neurodevelopmental impairments in preterm infants. This study was conducted to determine the incidence and natural course of various thyroid dysfunctions and their impacts on neurodevelopmental outcomes among premature infants. A total of 177 infants were enrolled who were born at <34 weeks or whose birth weight was <1500 g and who underwent repeat thyroid function tests. We analyzed how various thyroid dysfunctions affected neurodevelopmental outcomes at 18 months of corrected age. Thyroid dysfunction was noted in 88 infants. Hypothyroxinemia was observed in 23 infants, and their thyroid function was influenced by variable clinical factors. Free T4 levels were all normalized without thyroxine medication, and neurodevelopmental outcomes were not affected. In contrast, hyperthyrotropinemia was not associated with other clinical factors. Among 58 subjects who had hyperthyrotropinemia, only 31 infants showed normal thyroid-stimulating hormone (TSH) levels at follow-up tests. The remaining 27 infants had persistently high TSH levels, which significantly and poorly influenced the neurodevelopmental outcomes. Thyroid dysfunction is common among preterm infants. With the exception of persistent hyperthyrotropinemia, it generally does not affect neurodevelopmental outcomes. However, the beneficial effects of thyroid hormone therapy in patients with persistent hyperthyrotropinemia merits further study.

Maternal Hypothyroxinemia During Pregnancy and Growth of the Fetal and Infant Head

Severe maternal thyroid dysfunction during pregnancy affects fetal brain growth and corticogenesis. This study focused on the effect of maternal hypothyroxinemia during early pregnancy on growth of the fetal and infant head. In a population-based birth cohort, we assessed thyroid status in early pregnancy (median 13.4, 90% range 10.8-17.2), in 4894 women, and measured the prenatal and postnatal head size of their children at 5 time points. Hypothyroxinemia was defined as normal thyroid-stimulating hormone levels and free thyroxine-4 concentrations below the 10th percentile. Statistical analysis was performed using linear generalized estimating equation. Maternal hypothyroxinemia was associated with larger fetal and infant head size (overall estimate β: 1.38, 95% confidence interval 0.56; 2.19, P = .001). In conclusion, in the general population, even small variations in maternal thyroid function during pregnancy may affect the developing head of the young child.

Thyroid Function in Greek Patients with Thalassemia Major

AbstractAbstract 5176 Background:Disturbances of thyroid function is known to frequently occur in Thalassemia Major (TM); its types prevalence and severity vary in different cohorts. Primary hypothyroidism is caused by failure of thyroid function, while central (secondary) hypothyroidism by inefficient secretion of thyroid-stimulating hormone (TSH) due to pituitary gland dysfunction or reduced thyrotropin-releasing hormone (TRH) secretion from the hypothalamus. TSH levels in primary hypothyroidism are increased, while levels of free T4 (FT4) are decreased or within normal range. In secondary hypothyroidism FT4 levels are low and TSH levels normal or low.The main objective of this retrospective study was to assess the prevalence of central and primary hypothyroidism in a cohort of 364 Greek patients with TM (mean age 33. 0±9. 9 years, range: 1–56 years). Patients and Methods:Data from sequential laboratory evaluation on thyroid function in 364 patients with TM were retrospectively collected and analyzed. Assessment of thyroid function included measurements of TSH, T4, T3, FT4, FT3, anti-TPO, anti-TG by classical methods. Diagnostic criteria for primary hypothyroidism consisted of two consecutive measurements of low T4 or FT4 with increased TSH levels or two consecutive abnormally high levels of TSH despite normal levels of FT4, FT3, T4 and T3. The criteria for diagnosis of central hypothyroidism consisted of two consecutive measurements of low levels of T4 or FT4 with normal or low levels of TSH. In addition the age and ferritin levels at diagnosis of the hypothyroidism, as well as the type of thyroid treatment and chelation were recorded. To study the longitudinal prevalence of thyroid dysfunction, patients were stratified into 3 groups, according to the year of birth (Group A=1960–1970, 49 patients; Group B =1971–1980, 195 patients; Group C=1981–1990, 75 patients). As thyroid dysfunction increases with age, the incidence of thyroid disorders was compared between all three groups for patients ≤30years old, and for patients ≤40 years old between the groups A and B. Statistical analysis as well as BoxPlot values and regression lines presentation were performed using the STATGRAPHICS Centurion XVI. Statistical significance was set at p<0. 05. Results:A total of 364 patients (mean age 33. 0±9. 9 years, 180 females, 184 males) with TM were evaluated. Relevant data on the type and prevalence of thyroid dysfunction in all three groups of patients are summarized in table 1. Figure 1 illustrates the correlation between the age and the year of diagnosis of hypothyroidism.Comparing the data of the three age groups no significant differences in the overall prevalence of hypothryroidism was found. A significantly higher incidence of central hypothyroidism was found in group C compared to groups B and A (p=0. 00087, p=0. 0097 respectively) and higher prevalence of primary hypothyroidism in group A (for patients aged <40 years) in comparison with group B (p=0. 012). Ferritin levels at the time of diagnosis were significantly lower in group A compared to B and C and in group B compared to C (A/B p=0. 0014; B/C p=0. 0342; A/C p<0. 0001).A significant correlation (R2 =0. 47) was found between the age at diagnosis of hypothyroidism and the year of diagnosis (figure 1). Conclusions:The study demonstrated that thyroid disorders remain a frequent problem in Greek patients with TM with a trend of increasing prevalence with age and modification of the ratio of primary to secondary hypothyroidism. The increased incidence of central hypothyroidism in recent years could be attributed to an increased awareness and a more precise evaluation of this condition. The fact that ferritin levels at diagnosis were significantly higher in the younger age cohort may be suggestive that novel iron chelation modalities are more protective against iron-induced thyroid toxicity. Nevertheless, as toxicity may occur in early stages, the impact of these modalities in the incidence and severity of thyroid dysfunction may take years to be apparent.Table 1:Types and prevalence of thyroid dysfunction in three age cohorts of 364 TM patientsType of Thyroid DysfunctionGroup A (n=49)Group B (n=195)Group C (n=75)ALL (n=364)Primary % (n)16.3 (8)20 (39)21.3(16)17.6 (64)Secondary % (n)28.6 (14)21.5 (42)9.3 (7)17.3 (63)Thyroiditis % (n)4.0 (2)1.5 (3)1.3 (1)1.6 (6)Thyroid Cancer % (n)4.0 (2)0.5 (1)00.8 (3)Normal thyroid function % (n)46.9 (23)56.4 (110)68.0 (51)62.6 (228) [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Reversing Hypometabolic Symptoms by Normalizing Low Body Temperatures with Sustained-release T3 in Patients with Euthyroid TSH Levels

OBJECTIVE:&nbsp;Currently, the position of the American Thyroid Association is that hypothyroidism causes symptoms of metabolic slowing due to inadequate production of thyroid hormone by the thyroid gland; it is diagnosed by a lab result of a high thyroid stimulating hormone (TSH) level. While hypothyroidism is considered a chronic, incurable condition, the symptoms typically can be controlled by ingestion of thyroxine (T4) for life. Due to this conclusion, medical providers overall adhere to the assumption that people with normal TSH levels can not have thyroid-hormone-responsive symptoms; likewise, thyroid-hormone-responsive symptoms should not be treated with triiodothyronine T3 and are not reversible. Our objective was to examine if treatment with sustained-release (SR-T3), in patients with normal TSH values and low body temperatures, reduced symptoms consistent with low metabolic rate—and if improvement in symptoms remained even after discontinuation of the T3 treatment regimen. INTERVENTIONS:&nbsp;We report the results of 11 euthyroid outpatients with low body temperatures who took oral SR-T3 every 12 hours according to a cyclic dosing schedule designed to titrate low body temperatures to normal. The SR-T3 they took was formulated with the aim of delivering the T3 gradually over 12 hours. RESULTS:&nbsp;All of the patients in this study responded with an elevation in oral temperatures and improvement in five symptoms measured following the T3 treatment regimen. CONCLUSION:&nbsp;Patients exhibiting hypometabolism with normal TSH levels may experience a reversal of symptoms with normalization of low body temperatures on administration of a sustained-release T3 regimen such that their symptoms remain improved after the regimen has been discontinued.

Effect of Short-Term Infusive Dobutamine Therapy on Thyroid Hormone Profile and Hemodynamic Parameters in Patients With Acute Worsening Heart Failure and Low-Triiodothyronine Syndrome

ObjectivesLow-triiodothyronine syndrome (LT3S) is a condition characterized by decreased total serum T3 and free T3 (fT3) with normal levels of thyroxine (fT4) and thyrotropin (TSH). Experimental studies have shown that...

Subclinical hypothyroidism and myocardial function in obese children

Background and aimsPediatric obesity is an important health problem representing a major public health concern worldwide in the last decades. An isolated elevation of Thyroid Stimulating Hormone (TSH) with normal levels of thyroid hormones is frequently found in obese children. It has been named Isolated Hyperthyreotropinemia or Subclinical Hypothyroidism (SCH) and may be considered a consequence of obesity. Evidence exists that SCH is related to impairment of both systolic and diastolic myocardial function in the adult population.The aim of our study is to establish if obesity-related SCH influences myocardial function in children. Methods and resultsWe examined 34 obese children and adolescents with SCH and 60 obese children with normal TSH levels who underwent Doppler echocardiographic to evaluate myocardial function.Global systolic function as assessed by Ejection Fraction (EF) was comparable between groups, however Right Ventricle pressure global systolic function and pressure were significantly reduced in SCH group. Mitral annulus peak systolic (MAPSE) excursion lateral and MAPSE septum resulted significantly reduced in SCH group. Tissue Doppler imaging peak systolic motion (TDI-S) was reduced in SCH group. Diastolic function also showed significant modifications in SCH group. ConclusionThese results suggest possible involvement of cardiac function in obese children with SCH resulting in both abnormal diastolic function and reduced longitudinal systolic function. This new insight into cardiovascular consequences of obesity-related SCH in children could influence clinical approach to such patients by pediatric endocrinologists.

Thyroid hormones levels in Jordanian athletes participating in aerobic and anaerobic activities

Acute and prolonged exercises have controversial effect on the circulatory levels of thyroid hormones. The aim of the present study was to assess changes in thyroid hormones levels in elite top Jordanian athletes participating in both aerobic and anaerobic activities. Moreover, this work aims at comparing the level of thyroid hormones in both groups and to sedentary healthy subjects. Eighty Jordanian top level athletes with training experience of at least 5 years were included in this study. A group of healthy male and female adolescents (control group), matched for age and gender was also included (n = 50). Serum levels of free tri-iodothyronine (fT3), free thyroxin (fT4), thyroid-stimulating hormone (TSH) were examined. The results showed that although athletes showed normal levels of fT3, fT4 and TSH, the concentration of fT3 and TSH was significantly higher than control group. fT4 on the contrary, revealed significantly lower concentration compared to control. The levels of fT3, fT4 and TSH showed no significant differences between aerobic and anaerobic athletes. We concluded that long term exercise performed by athletes may have different impact on thyroid hormone levels in comparison with acute and intense exercise programs. Key words: Athletes, thyroid hormones, free tri-iodothyronine (fT3), free thyroxin (fT4), thyroid-stimulating hormone (TSH).

Unusual Case of Hypothyroidism in an Infant With Hepatic Hemangioma

Unusual Case of Hypothyroidism in an Infant With Hepatic Hemangioma

Minimally Invasive Follicular Thyroid Carcinoma Developed in Dyshormonogenetic Multinodular Goiter Due to Thyroid Peroxidase Gene Mutation

The occurrence of thyroid carcinoma in patients with congenital hypothyroidism (CH) caused by dyshormonogenesis is very rare, and has only been reported in one patient harboring mutations in the thyroid peroxidase (TPO) gene. We report on a 29-year follow-up of two consanguineous siblings with CH due to total iodide organification defect who also had sensorineural hearing loss. Molecular analysis revealed a novel biallelic mutation of the TPO gene in which phenylalanine substitutes serine at codon 292 (c.875C>T, p.S292F) in exon 8. Despite early initiation, adequate doses of levothyroxine treatment and consequently normal thyrotropin (TSH) levels, the proposita developed a huge multinodular goiter (MNG) and underwent total thyroidectomy due to tracheal compression. Pathological examination revealed a unifocal follicular thyroid carcinoma without vascular invasion in the left lobe of the thyroid gland. Our finding of follicular thyroid carcinoma arising from dyshormonogenetic MNG in a patient without elevated serum TSH levels indicates that genetic and environmental factors other than TSH level might be involved in the development of thyroid carcinoma in dyshormonogenetic MNG. Despite the rare occurrence of thyroid carcinoma in dyshormonogenetic MNG, we recommend long-term follow-up and regular neck ultrasound imaging to prevent delayed diagnosis of thyroid carcinoma.

Recurrent IVF failure: other factors

IVF failure is a problem for a couple in the singular but can be a tragedy in the plural. Recurrent IVF failure has multiple known causes but many which are not routinely considered as part of the posttreatment analysis. The reason is there are several causes associated with lifestyle and other causes related to pre-existing conditions that have only a tenuous or no apparent connection to fertility. This article examines the impact of obesity, cigarette smoke, uterine anatomy, body mass index, thyroid dysfunction, immune factors, the hereditary and acquired thrombophilias, and embryo transfer technique on recurrent IVF failure.

Non-alcoholic fatty liver disease across the spectrum of hypothyroidism

The aim of this study was to characterize the relationship between the broad spectrum of hypothyroidism and NAFLD. A cross-sectional study with 4648 health check-up subjects (2324 cases with hypothyroidism vs. age- and sex-matched controls) was conducted. The subjects were categorized as having either subclinical [thyroid-stimulating hormone (TSH) ≥4.1 mIU/L and normal free thyroixine (T(4)) level (0.7-1.8 ng/dl)] or overt hypothyroidism [free T(4)<0.7 ng/dl]. NAFLD was diagnosed on the basis of typical ultrasonographic findings, and alcohol consumption of less than 20 g/day in the absence of other causes of liver disease. The mean age of the subjects was 48.6±11.8 years and 62.4% were female. NAFLD was significantly associated with hypothyroidism (30.2% patients vs. 19.5% control, p<0.001). The prevalence of NAFLD and abnormal liver enzyme levels (ALT>33/25 IU/L) increased steadily with increasing grades of hypothyroidism (for NAFLD, subclinical: 29.9% and overt: 36.3%; for abnormal ALT, 20.1% and 25.9%, p<0.001, respectively). Multivariate regression analysis showed that NAFLD was statistically significantly associated with hypothyroidism (odds ratio (OR) 1.38, 95% confidence interval (CI), 1.17-1.62) and the grade of hypothyroidism in a dose-dependent manner (OR 1.36, 95% CI, 1.16-1.61 in subclinical hypothyroidism and OR 1.71, 95% CI, 1.10-2.66 in overt hypothyroidism). Subclinical hypothyroidism, even in the range of upper normal TSH levels, was found to be related to NAFLD in a dose-dependent manner. Hypothyroidism is closely associated with NAFLD independently of known metabolic risk factors, confirming a relevant clinical relationship between these two diseases.

Effect of In Utero Exposure of Iodinated Intravenous Contrast on Neonatal Thyroid Function

Administration of radioactive iodine to a pregnant woman for thyroid ablation has been shown to affect neonatal thyroid levels. Thus, there is a theoretical risk in affecting a neonate's thyroid level upon birth with prior administration of intravenous contrast containing iodine to a pregnant woman during a computed tomographic scan. However, there is no literature to support this theoretical risk. This study attempted to determine if there is any effect on a newborn's thyroid levels after exposure to this type of contrast material in utero. The medical charts of 96 pregnant women during the years 2004 through 2009 on whom computed tomographic scans were performed were reviewed. A total of 29 charts were excluded secondary to missing neonatal records, missed abortions, and intrauterine fetal demise. The rest were subdivided into those who received intravenous (IV) ± oral contrast material and those who did not. The medical records of the newborns of these patients were also reviewed. The subject group consisted of 61 pregnant women who received IV ± oral contrast and their 64 neonates. The control group consisted of 6 pregnant patients who did not receive IV contrast and their 6 neonates. Of the 64 neonates in the subject group, only one neonate was found to have a low thyroxine level with a normal thyroid stimulating hormone level. This infant was severely premature, being born at the 25th week of gestation, and developed respiratory distress syndrome and sepsis, which were potential confounding factors. All of the 6 neonates in the control group had normal thyroid levels. This study concludes that there is no significant adverse clinical risk of thyroid function abnormalities to the fetus after IV iodinated contrast material to their mothers.

Unusual pediatric co-morbility: autoimmune thyroiditis and cortico-resistant nephrotic syndrome in a 6-month-old Italian patient

We report on a case of autoimmune thyroiditis in a 6-month-old patient with cortico-resistant nephrotic syndrome. Normal serum levels of thyroid hormons and thyroid-stimulating hormone were detected with high titers of circulant antithyroid antibodies and a dysomogeneous ultrasound appearance of the gland, typical of autoimmune thyroiditis. The research of maternal thyroid antibodies was negative. This is the first case of autoimmune thyroiditis found in such a young patient with pre-existing nephrotic syndrome ever described in literature. This association is random because nephrotic syndrome does not have an autoimmune pathogenesis and the genes involved in autoimmune thyroiditis are not related to those of nephrotic syndrome.

Thyroid bone disease

Thyroid bone disease

A case of resistant ovary syndrome

A 21-year-old female with primary amenorrhea, sexual infantilism, and phenotypic female visited our Obstetrics and Gynecology Clinics. The patient showed elevated follicle stimulating hormone and luteinizing hormone, decreased estradiol, normal thyroidstimulating hormone and prolactin level that means hypergonadotropic hypogonadism with normal 46, XX karyotype. Under diagnostic laparoscopy, both ovaries were intact morphology, small but anatomically normal uterus and vagina. Ovarian biopsy was taken and reported abundant primodial follicles and sporadic preantral follicles. We concluded that final diagnosis is resistant ovarian syndrome.

Nutritional State Alters the Association between Free Triiodothyronine Levels and Mortality in Hemodialysis Patients

Background: Serum free triiodothyronine (fT3) level is suggested to be a risk factor for mortality in unselected dialysis patients. We investigated the prognostic value of serum fT3 levels and also low-T3 syndrome on overall survival in a large cohort of hemodialysis (HD) patients with normal thyroid-stimulating hormone levels. Methods: A total of 669 prevalent HD patients were enrolled in the study. Serum fT3 level was measured by enzyme immune assay in frozen sera samples at the time of enrollment. Overall mortality was assessed during 48 months of follow-up. Results: Baseline fT3 was 1.47 ± 0.43 (0.01–2.98) pg/ml, and low-T3 syndrome was present in 71.7% of the cases. During a mean follow-up of 34 ± 16 months, 165 (24.7%) patients died. fT3 level was a strong predictor for mortality in crude and adjusted Cox models including albumin or high-sensitivity C-reactive protein (hs-CRP). Further adjustment for both albumin and hs-CRP made the impact of fT3 on mortality disappear. The presence of low-T3 syndrome was associated with mortality in only the unadjusted model. Conclusions: Low-T3 syndrome is a frequent finding among HD patients, but it does not predict outcome. However, serum fT3 level is a strong and inverse mortality predictor, in part explained by its underlying association with nutritional state and inflammation.

Hyperthyrotropinemia in relation to endothelial dysfunction in obese adolescents

It has been shown that isolated elevation of thyroid stimulating hormone (hyperthyrotropinemia) is quite frequent in obese adolescents, but it is not clear whether this condition entails an increased risk related to body mass index (BMI). The aim of the current study was to investigate the relationship between hyperthyrotropinemia and endothelial dysfunction and other cardiovascular risk factors in obese adolescents. Seventeen obese adolescents with hyperthyrotropinemia (TSH ≥ 4.2 μUI/ml) (group 1), 21 obese adolescents with normal thyroid stimulating hormone (TSH) level (group 2) and 10 age- and sex-matched healthy lean controls were included in the study. Fasting blood glucose (FBG), lipid profile, insulin resistance (HOMA-IR) and thyroid hormones were determined. All participants were subjected to ultrasound recording of brachial artery diameter at rest and after reactive hyperemia (FMD) for assessment of endothelial function. BMI and free triiodothyronine (fT3) levels were higher in obese adolescents with hyperthyrotropinemia (group 1) than in those with normal TSH (group 2) (p < 0.05), but there were no significant differences between the two groups in other metabolic parameters (lipid profile and HOMA-IR). The FMD was significantly low in obese adolescents (groups 1 and 2) relative to controls (3.4 ± 18% in group 1 and 3.6 ± 2.2% in group 2 vs. 10.4 ± 3.1% in control subjects), but there was no statistical difference between obese adolescents with hyperthyrotropinemia (group 1) and those with normal TSH (group 2). There were positive correlations between TSH and BMI (p = 0.03) and between fT3 and BMI (p = 0.04), but no correlation between TSH and lipid profile, HOMA-IR or FMD. Hyperthyrotropinemia is not related to endothelial dysfunction or metabolic risk factors in obese adolescents.

Higher Serum Free Triiodothyronine Levels within the Normal Range Are Associated with Metabolic Syndrome Components in Type 2 Diabetic Subjects with Euthyroidism

Associations of thyroid hormones with visceral obesity and insulin resistance in obese subjects with euthyroidism have been reported. However, there are no such reports in subjects with type 2 diabetes. The purpose of our study is to observe a relationship between thyroid hormones and components of metabolic syndrome (MetS) in type 2 diabetic subjects with euthyroidism defined by normal thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels. Subjects were 301 Japanese patients with type 2 diabetes. Serum TSH, FT4, free triiodothyronine (FT3), and variables related to MetS were measured. MetS was defined by the Japanese criteria and the criteria of the National Cholesterol Education Program modified for Asians. We found that serum FT3 levels were significantly and positively associated with BMI, visceral fat area, systolic and diastolic blood pressure, estimated glomerular filtration rate, serum triglyceride, and urine C peptide as a marker of insulin production, whereas negatively with age and HbA1c. In contrast, fewer numbers of variables were associated with serum TSH and FT4 levels. By a multiple regression analysis, FT3 level was independently associated with components of MetS such as visceral fat area, systolic blood pressure, and fasting blood glucose levels. On the other hand, the presence of these MetS components was independently associated with FT3 levels and urine C peptide. In conclusion, these results suggest a significant relationship between serum FT3 levels and components of MetS in type 2 diabetic subjects with euthyroidism, and imply a role of FT3 in MetS in type 2 diabetes.