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1.  Prevalence, clinical and biochemical profile of subclinical hypothyroidism in normal population in Mumbai 
Background:
Subclinical Hypothyroidism (ScHt) affects 3–15% of the adult population. It's clinical and biochemical profile is not well defined, especially in Indian scenario. Our study aimed at screening normal population to define normative ranges of thyroid hormones and Serum thyroid stimulating hormone (S.TSH) and prevalence of ScHt and thyroid autoimmunity.
Materials and Methods:
Two-hundred thirty-seven normal subjects without family history of thyroid disease were evaluated for symptoms and laboratory tests for thyroid dysfunction and autoimmunity.
Results:
The thyroid function tests were as follows:
Euthyroid Group:
Mean values were: T3: 1.79 ± 0.42 ng/mL, T4: 10.23 ± 2.25 μg/dL, FT3: 1.88 ± 0.19 pg/mL, FT4: 1.12 ± 0.21 ng/dL, S.TSH: 2.22 ± 1.06 μlu/mL. 10.2% of euthyroid subjects had antimicrosomal antibodies (AMA) +ve (mean titer 1:918) and 23.6% were anti-thyroid peroxidase autoantibody (anti-TPO) +ve (mean titer 15.06 Au/mL). The euthyroid outlier range for S.TSH was 0.3–4.6 μlu/mL. The values were comparable in both the sexes. Those with S.TSH ≥ 5 μlu/mL were defined to have ScHt.
ScHt Group:
Prevalence of ScHt was 11.3% (M:F ratio 1:3.7). 74% belonged to 35–54 years age group and prevalence increased with age (post-menopausal females: prevalence 20%). S.TSH was 9.8 ± 7.22 μlu/mL, mean S.AMA was 1:5079 (40.7% positivity) and mean S.anti-TPO was 260 Au/mL (47.6% positivity). Majority were agoitrous (74%), and stage I goiter was seen in 26% of this population. Symptom score of 5–8 was seen in 55% ScHt subjects versus 35% normal subjects.
Conclusion:
Mean S.TSH in our population was 2.22 μlu/mL (euthyroid outliers: 0.3–4.6 μlu/mL); hence, S.TSH above 4.6 μlu/mL should be considered as abnormal. The prevalence of thyroid autoimmunity increases after age of 35 years. ScHt presents mainly in agoitrous form and with positive antibodies, suggesting autoimmunity as the cause.
doi:10.4103/2230-8210.111641
PMCID: PMC3712376  PMID: 23869302
Autoimmunity; normative ranges; prevalence; subclinical hypothyroidism
2.  Hyperthyroidism due to inappropriate TSH secretion with associated hyperprolactinaemia--a case report and review of the literature. 
Postgraduate Medical Journal  1984;60(703):328-335.
A patient with inappropriate thyrotrophin (TSH) secretion is described. She initially presented with classical hyperthyroidism during pregnancy, responded to propylthiouracil and, subsequently, had a normal delivery. Hyperthyroidism persisted and 7.5 months later a subtotal thyroidectomy was performed. After a further 16 months, mild symptoms of hyperthyroidism recurred. She again responded to propylthiouracil, but developed galactorrhoea. At that stage, it was noted that she had persistently elevated circulating TSH in the presence of elevated T4 and T3 levels. Her symptomatology was mild, although objective indices of thyroid activity, including pulse rate, BMR, sex hormone binding globulin and cholesterol, were indicative of hyperthyroidism. CT scan and tomography of the sella were normal. She had a markedly exaggerated TSH response to thyrotrophin releasing hormone (TRH). Basal TSH and responsiveness to TRH was suppressed by high dose dexamethasone. The TSH response to TRH was partially suppressed by exogenous T3, but there was no effect on basal TSH levels. TSH also decreased slightly with L-dopa and bromocriptine. Circulating TSH rose markedly during methimazole administration. TSH alpha and beta subunits were elevated and appropriate for the high TSH. In addition, both subunits increased following TRH. The patient had basal hyperprolactinaemia with an impaired prolactin (PRL) response to TRH and metoclopramide. PRL suppressed with L-dopa and bromocriptine. The remaining anterior pituitary function was intact. Most of the laboratory findings argue against the presence of a TSH producing pituitary tumour and the most likely cause for inappropriate TSH secretion in this patient is selective resistance of the thyrotroph to thyroid hormones. A mild element of peripheral resistance might also be present. The hyperprolactinaemia could be related to lactotroph resistance to thyroid hormone. The complexities of treatment in this patient are stressed. Therapy was initially attempted with low dose dexamethasone, but this had no effect. T3 treatment produced an exacerbation of her symptomatology and did not influence basal TSH, thyroid hormones, or 131I uptake. Bromocriptine administration for 11 months partially suppressed basal TSH without influencing T3 and there was an increase in T4. Methimazole did decrease her T4 and T3, but TSH and PRL rose to even greater levels. Her hyperthyroidism was eventually controlled with an ablative dose of 131I. Thyroid hormone will be given in an attempt to suppress her TSH.
PMCID: PMC2417872  PMID: 6429655
3.  Neonatal Thyroid Function in Seveso 25 Years after Maternal Exposure to Dioxin 
PLoS Medicine  2008;5(7):e161.
Background
Neonatal hypothyroidism has been associated in animal models with maternal exposure to several environmental contaminants; however, evidence for such an association in humans is inconsistent. We evaluated whether maternal exposure to 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a persistent and widespread toxic environmental contaminant, is associated with modified neonatal thyroid function in a large, highly exposed population in Seveso, Italy.
Methods and Findings
Between 1994 and 2005, in individuals exposed to TCDD after the 1976 Seveso accident we conducted: (i) a residence-based population study on 1,014 children born to the 1,772 women of reproductive age in the most contaminated zones (A, very high contamination; B, high contamination), and 1,772 age-matched women from the surrounding noncontaminated area (reference); (ii) a biomarker study on 51 mother–child pairs for whom recent maternal plasma dioxin measurements were available. Neonatal blood thyroid-stimulating hormone (b-TSH) was measured on all children. We performed crude and multivariate analyses adjusting for gender, birth weight, birth order, maternal age, hospital, and type of delivery. Mean neonatal b-TSH was 0.98 μU/ml (95% confidence interval [CI] 0.90–1.08) in the reference area (n = 533), 1.35 μU/ml (95% CI 1.22–1.49) in zone B (n = 425), and 1.66 μU/ml (95% CI 1.19–2.31) in zone A (n = 56) (p < 0.001). The proportion of children with b-TSH > 5 μU/ml was 2.8% in the reference area, 4.9% in zone B, and 16.1% in zone A (p < 0.001). Neonatal b-TSH was correlated with current maternal plasma TCDD (n = 51, β = 0.47, p < 0.001) and plasma toxic equivalents of coplanar dioxin-like compounds (n = 51, β = 0.45, p = 0.005).
Conclusions
Our data indicate that environmental contaminants such as dioxins have a long-lasting capability to modify neonatal thyroid function after the initial exposure.
Andrea Baccarelli and colleagues show that maternal exposure to a dioxin following the industrial accident in Seveso, Italy in 1976 is associated with modified neonatal thyroid function even many years later.
Editors' Summary
Background.
The thyroid, a butterfly-shaped gland in the neck, controls the speed at which the human body converts food into the energy and chemicals needed for life. In healthy people, the thyroid makes and releases two hormones (chemical messengers that travel around the body and regulate the activity of specific cells) called thyroxine (T4) and triiodothyronine (T3). The release of T4 and T3 is controlled by thyroid secreting hormone (TSH), which is made by the pituitary gland in response to electrical messages from the brain. If the thyroid stops making enough T4 and T3, a condition called hypothyroidism (an underactive thyroid) develops. Adults with hypothyroidism put on weight, feel the cold, and are often tired; children with hypothyroidism may also have poor growth and mental development. Because even a small reduction in thyroid hormone levels increases TSH production by the pituitary, hypothyroidism is often diagnosed by measuring the amount of TSH in the blood; it is treated with daily doses of the synthetic thyroid hormone levothyroxine.
Why Was This Study Done?
Although hypothyroidism is most common in ageing women, newborn babies sometimes have hypothyroidism. If untreated, “neonatal” hyperthyroidism can cause severe mental and physical retardation so, in many countries, blood TSH levels are measured soon after birth. That way, levothyroxine treatment can be started before thyroid hormone deficiency permanently damages the baby's developing body and brain. But what causes neonatal hypothyroidism? Animal experiments (and some but not all studies in people) suggest that maternal exposure to toxic chemicals called dioxins may be one cause. Dioxins are byproducts of waste incineration that persist in the environment and that accumulate in people. In this study, the researchers investigate whether exposure to dioxin (this name refers to the most toxic of the dioxins—2,3,7,8-Tetrachlorodibenzo-p-dioxin) affects neonatal thyroid function by studying children born near Seveso, Italy between 1994 and 2005. An accident at a chemical factory in 1976 heavily contaminated the region around this town with dioxin and, even now, the local people have high amounts of dioxin in their bodies.
What Did the Researchers Do and Find?
The researchers identified 1,772 women of child-bearing age who were living very near the Seveso factory (the most highly contaminated area, zone A) or slightly further away where the contamination was less but still high (zone B) at the time of the accident or soon after. As controls, they selected 1,772 women living in the surrounding, noncontaminated (reference) area. Altogether, these women had 1,014 babies between 1994 and 2005. The babies born to the mothers living in the reference area had lower neonatal blood TSH levels on average than the babies born to mothers living in zone A; zone B babies had intermediate TSH levels. Zone A babies were 6.6. times more likely to have a TSH level of more than 5 μU/ml than the reference area babies (the threshold TSH level for further investigations is 10 μU/ml; the average TSH level among the reference area babies was 0.98 μU/ml). The researchers also examined the relationship between neonatal TSH measurements and maternal dioxin measurements at delivery (extrapolated from measurements made between 1992 and 1998) in 51 mother–baby pairs. Neonatal TSH levels were highest in the babies whose mothers had the highest blood dioxin levels.
What Do These Findings Mean?
These findings suggest that maternal dioxin exposure has a long-lasting, deleterious effect on neonatal thyroid function. Because the long-term progress of the children in this study was not examined, it is not known whether the increases in neonatal TSH measurements associated with dioxin exposure caused any developmental problems. However, in regions where there is a mild iodine deficiency (the only environmental exposure consistently associated with reduced human neonatal thyroid function), TSH levels are increased to a similar extent and there is evidence of reduced intellectual and physical development. Future investigations on the progress of this group of children should show whether the long-term legacy of the Seveso accident (and of the high environmental levels of dioxin elsewhere) includes any effects on children's growth and development.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050161.
The MedlinePlus encyclopedia provides information about hypothyroidism and neonatal hypothyroidism; MedlinePlus provides links to additional information on thyroid diseases (in English and Spanish)
The UK National Health Service Direct health encyclopedia provides information on hypothyroidism
The Nemours Foundation's KidsHealth site has information written for children about thyroid disorders
Toxtown, an interactive site from the US National Library of Science, provides information on environmental health concerns including exposure to dioxins (in English and Spanish)
More information about dioxins is provided by the US Environmental Protection Agency and by the US Food and Drug Administration
Wikipedia has a page on the Seveso disaster (note: Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
doi:10.1371/journal.pmed.0050161
PMCID: PMC2488197  PMID: 18666825
4.  A Case of simultaneous occurrence of Marine – Lenhart syndrome and a papillary thyroid microcarcinoma 
Background
Marine-Lenhart syndrome is defined as the co-occurrence of Graves’ disease and functional nodules. The vast majority of autonomous adenomas are benign, whereas functional thyroid carcinomas are considered to be rare. Here, we describe a case of simultaneous occurrence of Marine-Lenhart syndrome and a papillary microcarcinoma embedded in a functional nodule.
Case presentation
A 55 year-old, caucasian man presented with overt hyperthyroidism (thyrotropin (TSH) <0.01 μIU/L; free thyroxine (FT4) 3.03 ng/dL), negative thyroid peroxidase and thyroglobulin autoantibodies, but elevated thyroid stimulating hormone receptor antibodies (TSH-RAb 2.6 IU/L). Ultrasound showed a highly vascularized hypoechoic nodule (1.1 × 0.9 × 2 cm) in the right lobe, which projected onto a hot area detected in the 99mtechnetium thyroid nuclear scan. Overall uptake was increased (4.29%), while the left lobe showed lower tracer uptake with no visible background-activity, supporting the notion that both Graves’ disease and a toxic adenoma were present. After normal thyroid function was reinstalled with methimazole, the patient underwent thyroidectomy. Histological work up revealed a unifocal papillary microcarcinoma (9 mm, pT1a, R0), positively tested for the BRAF V600E mutation, embedded into the hyperfunctional nodular goiter.
Conclusions
Neither the finding of an autonomously functioning thyroid nodule nor the presence of Graves’ disease rule out papillary thyroid carcinoma.
doi:10.1186/1472-6823-13-16
PMCID: PMC3654942  PMID: 23657056
Toxic adenoma; Graves’ disease; Marine-Lenhart syndrome; Papillary carcinoma; Hyperthyroidism
5.  Prospective Observation of 5-Year Clinical Course of Subclinical Hypothyroidism in Korean Population 
Journal of Korean Medical Science  2013;28(11):1622-1626.
Subclinical hypothyroidism (SCH) is a common clinical condition, whereas it's natural course has not been identified distinctly. We evaluated the natural history of 169 SCH patients over 5-yr and the prognostic factors including thyroid autoantibodies and thyroid ultrasonographic (USG) findings related to develop overt hypothyroidism. After 5 yr, 47.3% of patients showed normalization of TSH, while 36.7% of patients remained persistence of high level of TSH, and overt hypothyroidism developed in 11.2% of patients. There were painless thyroiditis (2.9%) and hyperthyroidism (1.7%) during 5 yr follow-up. The thyroid nodule was seen in 48.6% of patients. Most of patients had 1 to 2 nodules whereas only 3% of patients with thyroid nodule had more than 6 nodules. Overt hypothyroidism patients had more heterogenous echogenecity in USG compared to patients with normalization or persistent SCH (76.5% vs 50.0% vs 35.0%, P = 0.048) and higher prevalence positive anti-thyroid peroxidase (anti-TPO Ab) and anti-thyroglobulin antibody (anti-Tg Ab) and titer of anti-TPO Ab than other two groups. The cut off values for prediction of overt hypothyroidism were TSH > 7.45 µIU/mL, free T4 < 1.09 ng/dL and Anti-TPO Ab > 560 IU/mL. SCH has various courses and initial TSH, free T4, presence of thyroid autoantibody, titer of thyroid autoantibody; and thyroid USG findings can serve as a prognostic factor for progression of overt hypothyroidism. These parameters suggest consideration to initiate thyroid hormone treatment in SCH.
doi:10.3346/jkms.2013.28.11.1622
PMCID: PMC3835504  PMID: 24265525
Subclinical Hypothyroidism; Natural History; Hypothyroidism
6.  Metabolic Clearance and Production Rates of Human Thyrotropin 
Journal of Clinical Investigation  1974;53(3):895-903.
Metabolic clearance (MCR) and production rates (PR) of human thyrotropin (hTSH) were determined by the constant infusion to equilibrium method 57 times in 55 patients. 16 control patients had a mean hTSH MCR of 50.7 ml/min. The mean hTSH MCR was significantly (P < 0.02) higher in 19 euthyroid men (51.6 ml/min) than in 12 euthyroid women (43.0 ml/min), but this apparent sex difference disappeared when the MCR were corrected for surface area, 25.8 (men) versus 25.2 ml/min per m2 (women). Hypothyroid patients had significantly (P < 0.005) lower hTSH MCR (30.9 ml/min), and hyperthyroid patients had significantly (P < 0.05) higher hTSH MCR (60.9 ml/min) than controls. The hTSH MCR in patients with “decreased thyroid reserve” (40.9 ml/min), hyperfunctioning thyroid nodule (53.8 ml/min), and “empty sella syndrome” (46.6 ml/min) were not significantly different from controls. The mean hTSH PR in controls (104.3 mU/day) was significantly (P < 0.005) different from that in patients with “decreased thyroid reserve” (956 mU/day), hypothyroidism (4,440 mU/day), hyperthyroidism (< 43.9 mU/day) and a hyperfunctioning thyroid nodule (< 38.7 mU/day). In primary hypothyroidism intravenous triiodothyronine therapy (50 μg/day) for 10 days decreased the hTSH PR (from 4,244 to 2,461 mU/day) before changes in the hTSH MCR (from 33.1 to 33.7 mU/day) were observed.
These studies have demonstrated that changes in the serum concentration of hTSH are mainly due to altered pituitary hTSH secretion with only a minor contribution from the change in hTSH MCR.
PMCID: PMC333072  PMID: 4812446
7.  Suppression of Pituitary TSH Secretion in the Patient with a Hyperfunctioning Thyroid Nodule 
Journal of Clinical Investigation  1973;52(11):2783-2792.
10 patients with a single hyperfunctioning thyroid nodule each were studied for pituitary thyrotropin (TSH) suppression. They were judged to be euthyroid on clinical grounds. The total thyroxine (T4D), free thyroxine (FT4), total triiodothyronine (T3D), and free triiodothyronine (FT3) were normal in most of the patients. Incorporation of 131I into the hyperfunctioning thyroid nodules was not suppressed by the administration of physiological doses of T3. Basal serum TSH concentrations were undetectable (<0.5 - 1.0 μU/ml) in all patients. The metabolic clearance of TSH in one patient before and after excision of the thyroid nodule was unchanged (40 vs. 42 ml/min) whereas the calculated production rate was undetectable before the operation (<29 mU/day) and normal after (103 mU/day). These data, in one patient, suggest that the undetectable concentration of TSH in these patients is a result of suppressed TSH secretion rather than accelerated TSH clearance.
In eight patients, basal serum TSH concentrations failed to increase after the intravenous administration of 200 μg of thyrotropin-releasing hormone (TRH); minimal increases in serum TSH concentrations were observed in two patients. The suppression of TSH was evident despite “normal” concentrations of circulating thyroid hormones. The observation that normal serum concentrations of T4D, FT4, T3D, and FT3 may be associated with undetectable basal serum TSH concentrations and suppressed TSH response to TRH was also found in four hypothyroid patients given increasing doses of L-thyroxine and sequential TRH stimulation tests.
Images
PMCID: PMC302546  PMID: 4201265
8.  Longitudinal study on thyroid function in patients with thalassemia major: High incidence of central hypothyroidism by 18 years 
Introduction:
Primary hypothyroidism is one of the most frequent complications observed in-patients suffering from thalassemia. We investigated and reviewed the thyroid function in all thalassemic patients attending the Pediatric Endocrine Clinic of Hamad Medical Center, Doha, Qatar during the last 10 years of follow-up.
Patients and Methods:
A total of 48 patients with ί-thalassemia major between 5 years and 18 years of age. Thyroid dysfunction was defined as follows: Overt hypothyroidism (low Free thyroxine [FT4] and increased thyroid-stimulating hormone [TSH] levels >5 μIU/ml); subclinical hypothyroidism (normal FT4, TSH between 5 μIU/ml and 10 μIU/ml) and central (secondary) hypothyroidism (low FT4 and normal or decreased TSH).
Results:
A total of 48 patients (22 males and 26 females) completed a 12 year-period of follow-up. During this period, hypothyroidism was diagnosed in 17/48 (35%) of patients. There was no significant difference in the prevalence in males 7/22 (32%) versus females 10/26 (38%). Sixteen of the patients had hypothyroidism after the age of 10 years (94%). The prevalence of overt hypothyroidism had risen from 0% at the age of 7 years to 35% at the age of 18 years. None of the patients had high anti-thyroperoxidase antibody titers. Out of 17 patients, 13 patients with hypothyroidism had normal or low TSH level (not appropriately elevated) indicative of defective hypothalamic pituitary response to low FT4 (central hypothyroidism). Three patients (6.3%) had subclinical hypothyroidism (TSH between 5 uIU/ml and 10 uIU/ml and normal FT4). The general trend of FT4 level showed progressive decrease over the 12 years, whereas, TSH levels did not show a corresponding increase. These data suggested defective hypothalamic pituitary thyroid axis involving both TSH and FT4 sretion in patients with thalassemia major over time. There was a significant negative correlation between serum ferritin and FT4 (r = −0.39, P = 0.007), but no correlation was found between ferritin and TSH.
Conclusions:
Worsening of thyroid function was observed in 35% of the studied thalassemic patients by the age of 18 years. The lack of proper increase of TSH in response to the low circulating levels of FT4 in 13/17 (76%) of these patients indicates a relatively high incidence of defective pituitary thyrotrophic function in these patients.
doi:10.4103/2230-8210.122635
PMCID: PMC3872691  PMID: 24381890
Ferritin; free thyroxine; growth; hypothyroidism; prevalence; thalassemia; thyroid stimulating hormone
9.  Endogenous Thyrotropin and Triiodothyronine Concentrations in Individuals with Thyroid Cancer 
Thyroid  2008;18(9):943-952.
Background
Thyroid hormone suppression therapy is associated with decreased recurrence rates and improved survival in patients with differentiated thyroid cancer. Recently higher baseline thyrotropin (TSH) levels have been found to be associated with a postoperative diagnosis of differentiated thyroid cancer. Our objective was to confirm whether preoperative TSH levels were higher in patients who were diagnosed with differentiated thyroid cancer after undergoing thyroidectomy, compared with patients who were found to have benign disease. We also sought to determine whether thyroid hormone levels were lower in the patients with malignancy.
Methods
The study was a retrospective analysis of a prospective study. The study setting was the General Clinical Research Center of an Academic Medical Center. Participants were 50 euthyroid patients undergoing thyroidectomy. Thyroxine, triiodothyronine (T3), and TSH levels were documented in patients prior to their scheduled thyroidectomy. Following thyroidectomy, patients were divided into those with a histologic diagnosis of either differentiated thyroid cancer or benign disease. Preoperative thyroid profiles were correlated with patients' postoperative diagnoses.
Results
All patients had a normal serum TSH concentration preoperatively. One-third of the group was diagnosed with thyroid cancer as a result of their thyroidectomy. These patients had a higher serum TSH level (mean = 1.50 mIU/L, CI 1.22–1.78 mIU/L) than patients with benign disease (mean = 1.01 mIU/mL, CI 0.84–1.18 mIU/L). There was a greater risk of having thyroid cancer in patients with TSH levels in the upper three quartiles of TSH values, compared with patients with TSH concentrations in the lowest quartile of TSH values (odd ratio = 8.7, CI 2.2–33.7). Patients with a thyroid cancer diagnosis also had lower T3 concentrations measured by liquid chromatography tandem mass spectrometry (mean = 112.6 ng/dL, CI 103.8–121.4 ng/dL) than did patients with a benign diagnosis (mean 129.9 ng/dL, CI 121.4–138.4 ng/dL).
Conclusion
These data confirm that higher TSH concentrations, even within the normal range, are associated with a subsequent diagnosis of thyroid cancer in individuals with thyroid abnormalities. This further supports the hypothesis that TSH stimulates the growth or development of thyroid malignancy during its early or preclinical phase. We also show for the first time that patients with thyroid cancer also have lower T3 levels than patients with benign disease.
doi:10.1089/thy.2008.0061
PMCID: PMC2879493  PMID: 18788918
10.  Screening Strategies for Thyroid Disorders in the First and Second Trimester of Pregnancy in China 
PLoS ONE  2014;9(6):e99611.
Background
Thyroid dysfunction during pregnancy is associated with multiple adverse outcomes, but whether all women should be screened for thyroid disorders during pregnancy remains controversial.
Objective
To evaluate the effectiveness of the targeted high risk case-finding approach for identifying women with thyroid dysfunction during the first and second trimesters of pregnancy.
Methods
Levels of thyroid stimulating hormone (TSH), free thyroxine (FT4), and thyroid peroxidase antibodies (TPOAb) were measured in 3882 Chinese women during the first and second trimester of pregnancy. All tested women were divided into the high risk or non-high risk groups, based on their history, findings from physical examination, or other clinical features suggestive of a thyroid disorder. Diagnosis of thyroid disorders was made according to the standard trimester-specific reference intervals. The prevalence of thyroid disorders in each group was determined, and the feasibility of a screening approach focusing exclusively on high risk women was evaluated to estimate the ability of finding women with thyroid dysfunction.
Results
The prevalence of overt hypothyroidism or hyperthyroidism in the high risk group was higher than in the non-high risk group during the first trimester (0.8% vs 0, χ2 = 7.10, p = 0.008; 1.6% vs 0.2%, χ2 = 7.02, p = 0.008, respectively). The prevalence of hypothyroxinemia or TPOAb positivity was significantly higher in the high risk group than in the non-high risk group during the second trimester (1.3% vs 0.5%, χ2 = 4.49, p = 0.034; 11.6% vs 8.4%, χ2 = 6.396, p = 0.011, respectively). The total prevalence of hypothyroidism or hyperthyroidism and the prevalence of subclinical hypothyroidism or hyperthyroidism were not statistically different between the high risk and non-high risk groups, for either the first or second trimester.
Conclusion
The high risk screening strategy failed to detect the majority of pregnant women with thyroid disorders. Therefore, we recommend universal screening of sTSH, FT4, and TPOAb during the first trimester and second trimester of pregnancy.
doi:10.1371/journal.pone.0099611
PMCID: PMC4055732  PMID: 24925135
11.  Limited adequacy of thyroid cancer patient follow-up at a Canadian tertiary care centre 
Canadian Journal of Surgery  2013;56(6):385-392.
Background
We sought to evaluate the adequacy of follow-up of thyroid cancer patients at a Canadian centre.
Methods
We mailed a survey to the family physicians of thyroid cancer patients and analyzed the findings relative to follow-up guidelines published by the American Thyroid Association (ATA). Statistical significance between early and late follow-up patterns was analyzed using the χ2 test.
Results
Our survey response rate was 56.2% (91 of 162). The time from operation ranged from 1.24–7.13 (mean 3.96) years, and 87.9% of patients had undergone a physical exam within the previous year. Only 37.4% and 14% of patients had a serum thyroglobulin measurement within 6 and between 6 and 12 months before the survey, respectively. Thyroid simulating hormone (TSH) levels were measured within the prior 6 months in 67% of patients and between 6 and 12 months in 13.2%. The TSH levels were suppressed (< 0.1 μIU/L) in 24.2% of patients, 0.1–2 μIU/L in 44% and greater than 2 μIU/L in 17.6%. Ultrasonography was the most common imaging test performed.
Conclusion
There is significant variation in the follow-up patterns of patients with thyroid cancer, and there is considerable deviation from current ATA guidelines.
doi:10.1503/cjs.018112
PMCID: PMC3859780  PMID: 24284145
12.  Thyroid Function in Heart Failure and Impact on Mortality 
JACC. Heart failure  2013;1(1):48-55.
Objectives
The aim of this study was to investigate whether patients with systolic heart failure (HF) and abnormal thyroid function are at increased risk for death.
Background
Thyroid hormone homeostasis is vital to the optimal functioning of the cardiovascular system, but an independent prognostic effect of thyroid abnormalities in patients with HF has not been established.
Methods
In SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial), which randomized patients with ischemic or nonischemic HF to placebo or amiodarone or implantable cardioverter-defibrillator therapy, thyroid-stimulating hormone (TSH) was measured at baseline and at 6-month intervals throughout the 5-year study.
Results
Of 2,225 patients, the majority (87%) had normal TSH levels (0.3 to 5.0 μU/ml) at baseline, 12% had values suggestive of hypothyroidism, and 1% had values consistent with hyperthyroidism. Compared with euthyroid patients, those hypothyroid at baseline were older and included more women and Caucasians (all p values <0.05). Over the median follow-up period of 45.5 months, among patients euthyroid at baseline, 89 developed abnormally low TSH levels, and 341 developed abnormally high values. Patients randomized to amiodarone (median dose 300 mg) had an elevated risk for developing abnormal TSH levels compared with implantable cardioverter-defibrillator therapy or placebo (p < 0.0001). Patients with baseline or new-onset abnormal thyroid function had a higher mortality than those with normal thyroid function, even after controlling for other known mortality predictors (hazard ratio: 1.58; 95% confidence interval: 1.29 to 1.94; p < 0.0001 for hypothyroid; hazard ratio: 1.85; 95% confidence interval: 1.21 to 2.83; p = 0.0048 for hyperthyroid). Implantable cardioverter-defibrillator benefit did not vary with thyroid function.
Conclusions
Abnormal thyroid function in patients with symptomatic HF and ejection fractions ≤35% is associated with significantly increased risk for death, even after controlling for known mortality predictors. (Sudden Cardiac Death in Heart Failure Trial [SCD-HeFT]; NCT00000609)
doi:10.1016/j.jchf.2012.10.004
PMCID: PMC3803999  PMID: 24159562
amiodarone; heart failure; ICD; thyroid disease
13.  Hypothyroidism, new nodule formation and increase in nodule size in patients who have undergone hemithyroidectomy 
Introduction
The current medical literature has conflicting results about factors related to hypothyroidism and nodular recurrences during follow-up of hemithyroidectomized patients. We aimed to evaluate factors that may have a role in new nodule formation, hypothyroidism, increase in thyroid lobe and increase in nodule volumes in these patients with and without Hashimoto's thyroiditis (HT), and with and without levothyroxine (LT4) use.
Material and methods
We enrolled 140 patients from five different hospitals in Ankara and evaluated their thyroid tests, autoantibody titre results and ultrasonographic findings longitudinally between two visits with a minimum 6-month interval.
Results
In patients with HT there was no significant difference between the two visits but in patients without HT, thyroid stimulating hormone (TSH) levels and nodule volume were higher, and free T4 levels were lower in the second visit. Similarly, in patients with LT4 treatment there was no difference in TSH, free T4 levels, or lobe or nodule size between the two visits, but the patients without LT4 had free T4 levels lower in the second visit. Regression analysis revealed a relationship between first visit TSH levels and hypothyroidism during follow-up.
Conclusions
Patients who have undergone hemithyroidectomy without LT4 treatment and without HT diagnosis should be followed up more carefully for thyroid tests, new nodule formation and increase in nodule size. The TSH levels at the beginning of the follow-up may be helpful to estimate hypothyroidism in hemithyroidectomized patients.
doi:10.5114/aoms.2012.28222
PMCID: PMC3361026  PMID: 22661999
hemithyroidectomy; hypothyroidism; nodular goitre; Hashimoto's disease; thyroid lobectomy
14.  Thyroid disorders in women of Puducherry 
Thyroid stimulating hormone (TSH), Free Thyroxine (FT4) and Free Triiodothyronine (FT3) were assayed in 505 women of this region. 60 women had previous history of thyroid disease. The remaining 445 women formed the “Disease free group”. A “Reference group” was obtained by excluding women with previous and present history of thyroid dysfunction. Of the total 505 women examined 15.8% had thyroid dysfunction and 84.2% were euthyroid. 11.5% were hypothyroid (9.5% sub-clinical) and 1.8% hyperthyroid (1.2% clinical). The geometric mean TSH for the total population was 2.65 μIU/ml. It was significantly (p=0.025) lower in the reference population 2.17 μIU/ml. There was no significant difference in the FT3 and FT4 values between groups. 19% of women over 60 years had elevated TSH above 4.5 μIU/ml. The 2.5 and 97.5 percentiles of the reference population was 1.1–5.2 μIU/ml. 6.1% of women in the reference group had TSH levels above the reference intervals. Hypothyroidism particularly sub-clinical hypothyroidism is predominantly present amongst women in this iodine sufficient region. Evaluation of thyroid status could help in early detection and treatment.
doi:10.1007/s12291-009-0009-y
PMCID: PMC3453473  PMID: 23105807
Thyroid function; Hypothyroidism; Sub-clinical hypothyroidism
15.  Partial Target Organ Resistance to Thyroid Hormone 
Journal of Clinical Investigation  1973;52(4):776-782.
An 8-year old boy with a small goiter, normal basal metabolic rate (BMR), and elevated serum thyroid hormone levels (thyroxine [T4] 19.5 μg per 100 ml, free T4 4 ng per 100 ml, triiodothyronine [T3] 505 ng per 100 ml) was studied. He had measurable serum thyroid-stimulating hormone (TSH) levels (average 5.5 μU per ml), and the thyroxine-binding proteins, hearing, and epiphyseal structures were normal. There was no parental consanguinity nor were there thyroid abnormalities either in the parents or six siblings.
Methimazole, 50 mg daily, depressed thyroxine synthesis (T4 10.5, free T4 2.5) and caused a rise in TSH to 11 μU per ml. After discontinuation of treatment, TSH declined to 4.2 μU per ml and chemical hyperthyroidism returned (T4 21.0 μg per 100 ml, free T4 4.2, and total T3 475 ng per 100 ml, radioactive iodine [RAI] uptake 68%), but studies of BMR and insensible water loss showed the patient to be clinically euthyroid. Thyrotropin-releasing hormone (TRH), 200 μg i.v., caused a brisk rise in TSH to 28 μU per ml, with T4 rising to 28 μg per 100 ml, free T4 to 5.6, and T3 to 730 ng per 100 ml, thus indicating that the pituitary-thyroid system was intact and that the patient's TSH was biologically active. The unusual sensitivity of the pituitary cells to TRH in spite of the markedly elevated serum thyroid hormone levels also suggested that the pituitary was insensitive to suppression by T3 or T4. Serum dilution studies gave immunochemical evidence that this patient's TSH was normal. Neither propranolol, 60 mg, chlorpromazine, 30 mg, nor prednisone, 15 mg daily, influenced thyroid indices. Steroid treatment, however, suppressed the pituitary response to TRH, T3 in doses increased over a period of 12 days to as much as 150 μg daily caused a rise in serum T3 to above 800 ng per 100 ml, a decline of T4 to euthyroid levels (T4 9.5 μg per 100 ml, free T4 1.6 ng per 100 ml), suppression of the RAI uptake from 68% to 35%, and marked blunting of the responses to TRH, but the BMR and insensible water loss remained normal. The data suggest that the patient's disorder is due to partial resistance to thyroid hormone.
PMCID: PMC302323  PMID: 4632689
16.  Thyroid-Stimulating Hormone, White Matter Hyperintensities, and Functional Outcome in Acute Ischemic Stroke Patients 
Background
Thyroid-stimulating hormone (TSH) concentrations are frequently altered in acute ischemic stroke patients. It is becoming increasingly apparent that various hormones in the hypothalamus-pituitary-thyroid axis may be associated with functional stroke outcome. We have previously shown that white matter hyperintensities (WMH) of presumed vascular origin are strong indicators of functional outcome. It is unclear whether an association exists between WMH and TSH. We therefore sought to determine whether TSH levels, measured in acute ischemic stroke patients, are associated with WMH and functional outcome.
Methods
We analyzed all first ischemic stroke patients who participated in the Berlin ‘Cream & Sugar’ Study (NCT 01378468) and completed a 1-year follow-up assessment from January 2009 to March 2013. Patients were stratified into 3 groups: (1) low TSH (0.1-0.44 μU/ml); (2) normal TSH (0.44-2.5 μU/ml), and (3) high TSH (2.5-20 μU/ml). WMH were assessed using the Fazekas and Wahlund visual rating scales. Functional outcome was assessed using the modified Rankin Scale and was performed via telephone at 1 year by a certified rater.
Results
183 patients were included [median age 66, interquartile range (IQR) 54-75; 33% females; median National Institute of Health Stroke Scale 3, IQR 1-4, range 0-24]. Venous samples were collected a median of 4 days (IQR 3-5) following initial symptom onset between 8 and 9 a.m. following a 10-hour fast. Patients with normal TSH levels (n = 132; 72%) had significantly higher rates of prestroke diabetes than patients with high TSH levels (normal TSH 17%; high TSH 1%; p = 0.03). Additionally, patients with normal TSH levels tended to have higher estimated glomerular filtration rates than patients with high and low TSH concentrations (normal TSH median estimated glomerular filtration rates: 83 ml/min/1.73 m2; high TSH median estimated glomerular filtration rates: 76 ml/min/1.73 m2; low TSH median: 78 ml/min/1.73 m2; p = 0.068). Logistical regression analysis force-adjusted for age (quartiles), NIHSS (quartiles), prestroke diabetes status, and stroke subtype revealed significant associations between WMH and TSH [Wahlund scores: odds ratio 2.547, 95% confidence interval (CI) 1.159-5.598, p = 0.020; Fazekas scores: odds ratio 2.530, 95% CI 1.115-5.741, p = 0.003]. Functional outcome was not significantly associated with TSH levels in univariate or multivariate models.
Conclusion
TSH levels are independently associated with WMH in acute ischemic stroke patients. Based on our findings, we cannot recommend assessing TSH to estimate the 1-year functional outcome following ischemic stroke.
doi:10.1159/000360217
PMCID: PMC3995386  PMID: 24803914
Stroke; Ischemia; Hyperthyroidism; Hypothyroidism; Thyrotropin; White matter hyperintensities; Leukoaraiosis

17.  Variable Thyrotropin Response to Thyrotropin-releasing Hormone after Small Decreases in Plasma Free Thyroid Hormone Concentrations in Patients with Nonthyroidal Diseases 
Journal of Clinical Investigation  1980;66(3):451-456.
Although a normal serum thyrotropin (TSH) concentration is generally considered to be the most important finding to support the clinical impression of euthyroidism in patients with nonthyroidal diseases and decreased serum triiodothyronine (T3), the regulation of TSH secretion in sick patients has not been studied previously. Accordingly, we studied the regulation of TSH secretion in 23 patients with nonthyroidal diseases; 15 of the patients had decreased serum T3. TSH regulation was studied by measuring the TSH response to injected thyrotropin-releasing hormone (TRH) before and after effecting a small decrease in serum thyroxine (T4) and/or T3 concentrations by iodide treatment, 262 mg daily for 10 d. Iodide treatment significantly decreased (> 10%) the free T4 index (FT4-I) and/or free T3 index (FT3-I) in all patients. FT4-I values were correlated (0.611, P < 0.001), with free T4 concentration determined by equilibrium dialysis. Despite decreased FT4-I and/or FT3-I after iodide treatment in all patients, the TSH response to TRH after iodide treatment was augmented in only 8 of 15 patients who had decreased serum T3 (group 1) and in only 5 of 8 patients who had a normal serum T3. Mean base-line TSH concentration was increased significantly (P < 0.05) from 0.9±0.1 to 1.5±0.3 μU/ml in group 1 only. Comparison of the mean TSH response to TRH showed that there was no significant difference between groups 1 and 2. Moreover, no significant difference in thyroidal parameters was observed between patients who had augmented TSH response to TRH after iodides and those who had either similar or decreased TSH response irrespective of the initial serum T3. These studies show that an augmented TSH response to TRH in response to a small reduction in serum T4 and T3 concentration occurred in only 57% of the entire group of patients with nonthyroidal diseases and that the presence or absence of a normal TSH response to this stimulus did not seem to be related to the base-line serum T3 concentration. Because an increase in serum TSH in response to decreased serum T4 and T3 did not occur in about one-half of patients with nonthyroidal diseases, normal serum TSH may not be a reliable index of the euthyroid state in these patients.
PMCID: PMC371672  PMID: 6772675
18.  Thyrotropin-induced hyperthyroidism caused by selective pituitary resistance to thyroid hormone. A new syndrome of "inappropriate secretion of TSH". 
Journal of Clinical Investigation  1975;56(3):633-642.
An 18-yr-old woman with clinical and laboratory features of hyperthyroidism had persistently elevated serum levels of immunoreative thyrotropin (TSH). During 11 yr of follow-up there had been no evidence of a pituitary tumor. After thyrotropin-releasing hormone (TRH), there was a marked increase in TSH and secondarily in triiodothyronine (T3), the latter observation confirming the biologic activity of the TSH. Exogenous T3 raised serum T3 and several measurements of peripheral thyroid hormone effect, while decreasing serum TSH, thyroxine (T4), and thyroidal radioiodine uptake. After T3, the TRH-stimulated TSH response was decreased but was still inappropriate for the elevated serum T3 levels. Dexamethasone reduced serum TSH but did not inhibit TRH stimulation of TSH. Propylthiouracil reduced serum T4 and T3 and raised TSH. This patient represents a new syndrome of TSH-induced hyperthyroidism, differing from previous reports in the absence of an obvious pituitary tumor and in the responsiveness of the TSH to TRH stimulation and thyroid hormone suppression. This syndrome appears to be caused by a selective, partial resistance of the pituitary to the action of thyroid hormone. This case is also compared with previous reports in the literature of patients with elevated serum levels of immunoreactive TSH in the presence of elevated total and free thyroid hormones. A classification of these cases, termed "inappropriate secretion of TSH," is proposed.
PMCID: PMC301911  PMID: 1159077
19.  Lithium treatment and thyroid abnormalities 
Background
Although the interactions between lithium treatment and thyroid function have long been recognised, their clinical relevance is still controversial. This paper sets out a review of the literature to date, considering that lithium still represents the gold standard among prophylactic treatments of manic-depression several decades after its introduction.
Method
PubMed database was used to search for English-language articles relating to lithium treatment and thyroid function. As the amount of relevant papers totalled several hundreds, this review refers to previous reviews, especially with regard to older literature. Moreover, the authors particularly refer to a series of studies of thyroid function performed in a cohort of patients at different stages of lithium treatment, who were followed up by their group from 1989 onwards.
Results
The main findings from this review included: a) lithium definitely affects thyroid function as repeatedly shown by studies on cell cultures, experimental animals, volunteers, and patients; b) inhibition of thyroid hormone release is the critical mechanism in the development of hypothyroidism, goitre, and, perhaps, changes in the texture of the gland which are detected by ultrasonic scanning; c) compensatory mechanisms operate and prevent the development of hypothyroidism in the majority of patients; d) when additional risk factors are present, either environmental (such as iodine deficiency) or intrinsic (immunogenetic background), compensatory potential may be reduced and clinically relevant consequences may derive; e) hypothyroidism may develop in particular during the first years of lithium treatment, in middle-aged women, and in the presence of thyroid autoimmunity; f) thyroid autoimmunity is found in excess among patients suffering from affective disorders, irrespective of lithium exposure; g) in patients who have been on lithium for several years, the outcome of hypothyroidism, goitre, and thyroid autoimmunity do not much differ from those observed in the general population; h) hyperthyroidism and thyroid cancer are observed rarely during lithium treatment.
Recommendations
Thyroid function tests (TSH, free thyroid hormones, specific antibodies, and ultrasonic scanning) should be performed prior to starting lithium prophylaxis. A similar panel should be repeated at one year. Thereafter, annual measurements of TSH may be sufficient to prevent overt hypothyroidism. In the presence of raised TSH or thyroid autoimmunity, shorter intervals between assessments are advisable (4–6 months). Measurement of antibodies and ultrasonic scanning may be repeated at 2-to-3-year intervals. The patient must be referred to the endocrinologist if TSH concentrations are repeatedly abnormal, and/or goitre or nodules are detected. Thyroid function abnormalities should not constitute an outright contraindication to lithium treatment, and lithium should not be stopped if a patient develops thyroid abnormalities. Decisions should be made taking into account the evidence that lithium treatment is perhaps the only efficient means of reducing the excessive mortality which is otherwise associated with affective disorders.
doi:10.1186/1745-0179-2-23
PMCID: PMC1584230  PMID: 16968542
20.  Management of Subclinical Hyperthyroidism 
The ideal approach for adequate management of subclinical hyperthyroidism (low levels of thyroid-stimulating hormone [TSH] and normal thyroid hormone level) is a matter of intense debate among endocrinologists. The prevalence of low serum TSH levels ranges between 0.5% in children and 15% in the elderly population. Mild subclinical hyperthyroidism is more common than severe subclinical hyperthyroidism. Transient suppression of TSH secretion may occur because of several reasons; thus, corroboration of results from different assessments is essential in such cases. During differential diagnosis of hyperthyroidism, pituitary or hypothalamic disease, euthyroid sick syndrome, and drug-mediated suppression of TSH must be ruled out. A low plasma TSH value is also typically seen in the first trimester of gestation. Factitial or iatrogenic TSH inhibition caused by excessive intake of levothyroxine should be excluded by checking the patient’s medication history. If these nonthyroidal causes are ruled out during differential diagnosis, either transient or long-term endogenous thyroid hormone excess, usually caused by Graves’ disease or nodular goiter, should be considered as the cause of low circulating TSH levels.
We recommend the following 6-step process for the assessment and treatment of this common hormonal disorder: 1) confirmation, 2) evaluation of severity, 3) investigation of the cause, 4) assessment of potential complications, 5) evaluation of the necessity of treatment, and 6) if necessary, selection of the most appropriate treatment.
In conclusion, management of subclinical hyperthyroidism merits careful monitoring through regular assessment of thyroid function. Treatment is mandatory in older patients (> 65 years) or in presence of comorbidities (such as osteoporosis and atrial fibrillation).
doi:10.5812/ijem.3447
PMCID: PMC3693616  PMID: 23843809
Hyperthyroidism; Disease Management; Therapeutics; Graves’ Disease
21.  Hyperthyroidism unmasked several years after the medical and radiosurgical treatment of an invasive macroprolactinoma inducing hypopituitarism: a case report 
Cases Journal  2009;2:6449.
Introduction
Measuring thyroid stimulating hormone levels alone may be insufficient to appropriately evaluate thyroid function. Reduced thyroid stimulating hormone levels associated to normal/reduced FT4 levels should prompt investigation of pituitary function, on suspicion of hypopituitarism. Pituitary macroadenomas are the most common cause of hypopituitarism; among these, macroprolactinomas are usually treated with dopamine-agonist therapy. Hypopituitarism does not preclude the development of primary hyperthyroidism. This report describes the case of a patient with a final diagnosis of macroprolactinoma inducing hypopituitarism, who subsequently developed hyperthyroidism due to a toxic thyroid nodule.
Case presentation
A 62-year-old man underwent biochemistry and thyroid function assessment for asthenia. Reduced thyroid stimulating hormone levels were associated to slightly decreased FT4 levels and low-normal FT3 levels; thyroid ultrasonography showed a multinodular goiter. Thyroid scan with 99mTc-pertechnetate revealed an autonomous left nodule with suppression of the surrounding parenchyma. Pituitary investigation showed partial hypopituitarism associated to increased prolactin levels: 182-200 ng/ml. Magnetic resonance imaging revealed a large (2.2 cm) invasive macroadenoma. To avoid a possible high-dose hook effect, the patient's serum was diluted; the resulting PRL levels of around 1800 ng/ml prompted the final diagnosis of macroprolactinoma. Reduced libido and erectile dysfunction were ascertained. In addition to replacement therapy with L-thyroxine and testosterone, cabergoline was started and was progressively increased to high doses (4 g/week); this yielded a significant but incomplete reduction of PRL levels (63-99 ng/ml). Sexual function improved. The macroadenoma shrank over the first two years of therapy, but subsequently enlarged slightly. Following stereotactic radiosurgery, the tumor stabilized and prolactin almost normalized (22 ng/ml) on therapy. Over the years, thyroid nodule volume was unmodified, but hyperthyroidism on L-thyroxine therapy was found, and increased FT3 levels with suppressed thyroid stimulating hormone levels were confirmed off-therapy. Thyroid scan confirmed the left autonomous nodule, which was successfully treated with methimazole.
Conclusion
Reduced thyroid stimulating hormone levels associated to normal/reduced free-thyroid hormone levels may be the first clue to unsuspected hypopituitarism. Moderately increased prolactin levels in the presence of a large macroadenoma warrant serum dilution in order to avoid a possible hook effect. Stereotactic radiosurgery is a useful non-invasive tool in the management of pituitary tumors. A pre-toxic thyroid nodule with low secretory activity may initially be masked by the coexistence of secondary hypothyroidism, but may lead to overt hyperthyroidism over time.
doi:10.4076/1757-1626-2-6449
PMCID: PMC2740230  PMID: 19829805
22.  Bone mineral density and bone turnover markers in patients on long-term suppressive levothyroxine therapy for differentiated thyroid cancer 
Purpose
Current management for patients with differentiated thyroid cancer includes near total thyroidectomy and radioactive iodine therapy followed by administration of supraphysiological doses of levothyroxine (L-T4). Although hyperthyroidism is a well known risk factor for osteoporosis, the effects of L-T4 treatment on bone mineral density (BMD) in patients with thyroid cancer do not appear to be as significant as with endogenous hyperthyroidism. In this study, we evaluated the impact of long-term suppressive therapy with L-T4 on BMD and bone turn over markers in Korean female patients receiving L-T4 suppressive therapy.
Methods
We enrolled 94 female subjects (mean age, 50.84 ± 11.43 years) receiving L-T4 after total or near total thyroidectomy and radioactive iodine therapy for thyroid cancer (mean follow-up period, 12.17 ± 4.27 years). The subjects were divided into three groups by thyroid stimulating hormone (TSH) level (group 1 with TSH level ≤0.001 µIU/mL, group 2 with TSH level between 0.001 and 0.17 µIU/mL, group 3 with TSH level >0.17 µIU/mL) and four groups by quartile of free T4 level. L-T4 dosage, BMD (examined by dual-energy x-ray absorptiometry), and bone turnover markers were evaluated according to TSH and free T4 levels.
Results
No significant decrease was detected in BMD or bone turnover markers according to TSH level or free T4 level. Also, the prevalence of osteoporosis and osteopenia was not different among groups.
Conclusion
Long-term L-T4 suppressive therapy after thyroid cancer management did not affect bone density or increase the prevalence of osteoporosis even though TSH levels were supraphysiologically suppressed.
doi:10.4174/astr.2014.86.2.55
PMCID: PMC3994597  PMID: 24761409
Thyroid neplasms; Levothyroxine; Bone mineral density; Osteoporosis; Osteopenia
23.  Newborn TSH in children with optic nerve hypoplasia: Associations with hypothyroidism and vision 
Purpose
To assess in children with optic nerve hypoplasia (ONH) whether newborn screening (NBS) thyroid-stimulating hormone (TSH) measurements can detect central hypothyroidism and whether newborn TSH or subsequent thyroidal status is associated with visual function.
Methods
A subset of patients in the registry of children with ONH at Children’s Hospital Los Angeles who were born in California was used to make a retrospective comparison of NBS TSH levels and subsequent postnatal thyroid status. Another subset of registry subjects with vision and thyroid status data at age 5 years was assessed for the relationship of vision to NBS TSH levels and ultimate thyroidal status.
Results
A total of 135 subjects from the ONH registry were included in this study. Approximately 50% of subjects in each analysis were hypothyroid. Those diagnosed with hypothyroidism had lower median NBS TSH levels than did euthyroid subjects (3.2 vs 4.5 μIU/mL; P = 0.006) and significantly worse quantitative vision outcomes (median visual acuity, logMAR 3.0 vs 1.0; P = 0.039). Receiver operating characteristic analysis suggested an optimal NBS TSH cut-point of 3.3 μIU/mL. Serum TSH over this level (30/43) was associated with relatively better vision outcomes (median visual acuity, logMAR 1.2 vs 3.3; P = 0.04).
Conclusions
Children with ONH and lower NBS TSH levels are more likely to have central hypothyroidism and less likely to experience good vision than those with higher NBS TSH levels.
doi:10.1016/j.jaapos.2012.05.012
PMCID: PMC3481172  PMID: 23084376
24.  Hypothyroidism and Renal Function in Patients with Systolic Heart Failure 
Texas Heart Institute Journal  2010;37(1):66-69.
The extent to which hypothyroidism affects renal function in patients with heart failure remains incompletely explored, despite the known adverse prognostic implications of renal dysfunction in these patients.
In a pilot retrospective study, we evaluated 75 patients (age, ≥18 yr) with left ventricular ejection fractions <0.40. Forty-five patients had normal thyroid function (thyroid-stimulating hormone [TSH], 0.35–5.5 μIU/mL) and 30 had hypothyroidism. The group with hypothyroidism was subdivided into 17 patients who had controlled hypothyroidism (TSH, 0.35–5.5 μIU/mL) and 13 who had uncontrolled hypothyroidism (TSH, >5.5 μIU/mL). Renal function, measured in terms of glomerular filtration rate, was analyzed once in each patient, and the populations were statistically compared, with P <0.05 conferring statistical significance.
Baseline characteristics in all groups were similar. Mean glomerular filtration rate was better in patients with normal thyroid function than those with hypothyroidism (75.45 ± 31.48 vs 63.95 ± 21.43 mL/min/1.73 m2; P=0.032). There was no significant difference between patients with controlled hypothyroidism (66.89 ± 24.18 mL/min/1.73 m2) and those with normal thyroid function (P=0.131). In patients with uncontrolled hypothyroidism, mean glomerular filtration rate (60.2 ± 17.4 mL/min/1.73 m2) was significantly worse than in patients with normal thyroid function (P=0.015).
We found that heart-failure patients with insufficiently treated hypothyroidism have worse renal function than do patients whose thyroid function is normal or whose hypothyroidism is effectively treated. Larger studies will be needed in order to evaluate this conclusion further. We recommend that hypothyroidism in heart-failure patients be strictly controlled, lest it affect prognosis adversely.
PMCID: PMC2829818  PMID: 20200629
Comorbidity; glomerular filtration rate; heart failure/complications/epidemiology/mortality; hypothyroidism/complications/physiopathology; kidney/physiopathology; kidney function tests; prognosis; risk factors; thyroid function tests; thyroid diseases/complications; thyroid hormones/physi-ology
25.  Level of Thyroid-Stimulating Hormone (TSH) in Patients with Acute Schizophrenia, Unipolar Depression or Bipolar Disorder 
Neurochemical Research  2014;39:1245-1253.
The aim of this study is to investigate differences in thyroid-stimulating hormone (TSH) level in patients with acute schizophrenia, unipolar depression, bipolar depression and bipolar mania. Serum level of TSH was measured in 1,685 Caucasian patients (1,064 women, 63.1 %; mean age 46.4). Mean serum TSH concentration was: schizophrenia (n = 769) 1.71 μIU/mL, unipolar depression (n = 651) 1.63 μIU/mL, bipolar disorder (n = 264) 1.86 μIU/mL, bipolar depression (n = 203) 2.00 μIU/mL, bipolar mania (n = 61) 1.38 μIU/mL (H = 11.58, p = 0.009). Depending on the normal range used, the overall rate of being above or below the normal range was 7.9–22.3 % for schizophrenia, 13.9–26.0 % for unipolar depression, 10.8–27.6 % for bipolar disorder, 12.2–28.5 % for bipolar depression, and 11.4–24.5 % for bipolar mania. We have also found differences in TSH levels between the age groups (≤20, >20 years and ≤40, >40 years and ≤60 years and >60 years). TSH level was negatively correlated with age (r = − 0.23, p < 0.001). Weak correlations with age have been found in the schizophrenia (r = − 0.21, p < 0.001), unipolar depression (r = − 0.23, p < 0.001), bipolar depression (r = − 0.25, p = 0.002) and bipolar disorder (r = − 0.21, p = 0.005) groups. Our results confirm that there may be a higher prevalence of thyroid dysfunctions in patients with mood disorders (both unipolar and bipolar) and that these two diagnostic groups differ in terms of direction and frequency of thyroid dysfunctions.
doi:10.1007/s11064-014-1305-3
PMCID: PMC4103998  PMID: 24723220
Thyroid-stimulating hormone; Schizophrenia; Depression; Bipolar disorder

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