The thyroid epidemiology, audit, and research study: thyroid dysfunction in the general population

Hypothyroidism

Hypothyroidism, the deficiency of thyroid hormone, is a common condition worldwide. It affects almost all body systems and has a wide variety of clinical presentations from being asymptomatic to, in rare cases, life threatening. The classic symptoms of hypothyroidism include fatigue, lethargy, weight gain, and cold intolerance; however, these symptoms are non-specific and the diagnosis is typically made on biochemical grounds through serum thyroid function tests. The most common cause of hypothyroidism is chronic autoimmune thyroiditis (Hashimoto's thyroiditis), although other causes, including drugs (such as amiodarone, lithium, and immune checkpoint inhibitors), radioactive-iodine treatment, and thyroid surgery, are frequent. Historically, severe iodine deficiency was the most common cause. Reference ranges for thyroid function tests are based on fixed percentiles of the population distribution, but there is increasing awareness of the need for more individualised reference intervals based on key factors such as age, sex, and special circumstances such as pregnancy. Levothyroxine monotherapy is the standard treatment for hypothyroidism; it is safe and inexpensive, restores thyroid function tests to within the reference range, and improves symptoms in the majority of patients. However, 10% of patients have persistent symptoms of ill health despite normalisation of thyroid function tests biochemically and a substantial proportion of patients on levothyroxine have thyroid-stimulating hormone concentrations outside the reference range. Ongoing symptoms despite levothyroxine treatment has led to some patients using liothyronine or desiccated thyroid extract. Taken together, these factors have led to intense debate around the treatment thresholds and treatment strategies for hypothyroidism. In this Seminar, we review the epidemiology, genetic determinants, causes, and presentation of hypothyroidism; highlight key considerations and controversies in its diagnosis and management; and provide future directions for research.

Graves-Basedow ophthalmopathy surgical approaches: Open vs Endoscopic

Graves-Basedow's disease (GBD) is an autoimmune pathology that affects the thyroid and is characterized by the presence of goiter, hyperthyroidism, ophthalmopathy, and dermopathy. Graves-Basedow ophthalmopathy (GBO) is a set of inflammatory and infiltrative alterations of the orbital tissue that affects 40-90% of subjects suffering from GBD. Our study aims to investigate the differences in the clinical outcomes of patients treated with two different techniques: the classic open and the more modern endoscopic. A retrospective clinical study was carried out from the year 2011 until the year 2020 to evaluate the clinical outcomes of two different surgical techniques for the treatment of GBO. Eighteen patients were given surgical indications, 12 males and 6 females aged between 37 and 69 years (average age 48.5 years), for a total of 36 orbits. From the year 2011 to the year 2014, all patients were treated with the open orbital decompression technique; from 2015 onwards, patients were subjected to orbital decompression with the endoscopic transnasal approach. Pre- and postoperative ophthalmometry, reduction of proptosis, and reduction of oculo-orbital index were compared for the two techniques. As evidenced by the statistical analysis carried out on the sample before and after surgical treatment, there is a statistically significant difference between ophthalmometry and the Oculo-Orbital Index (IOO) values; this indicates that surgical orbital decompression with two walls (floor and medial wall) is effective in reducing exophthalmos. The positive result is also confirmed by the reduction of proptosis, measured in millimeters, averaging 1.7 mm. In the analysis of data relating to the two different patient groups, treated respectively with endoscopic orbital decompression (Technique 1) and classical open orbital decompression (Technique 2), the results obtained show that there is no statistically significant difference between the results of the two techniques. Therefore, the choice of surgical approach is at the discretion of the surgeon. It is our opinion that orbital decompression with the endoscopic transnasal technique should be an absolute indication in all patients who have clinical and radiographic signs of involvement of the optic nerve at the orbital apex (crowded apex syndrome) thanks to the ability of this technique to add and decompress the optical channel at the apex. For all other patients with GBO, the endoscopic technique of orbital decompression can be indicated as a first-line surgical approach considering the absence of skin scars and the best aesthetic results.

Thyroid disease in ANCA-associated vasculitis: a clinical and epidemiological study

OBJECTIVES

To describe clinical and laboratory characteristics and outcomes in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and thyroid disease (TD). We also aimed to calculate incidence and identify predictors of TD in two large cohorts of patients with AAV.

METHODS

The study comprised 644 patients with AAV in a population-based cohort from southern Sweden (n=325) and a cohort from a specialised vasculitis centre in Cambridge, UK (n=319). Diagnosis and classification of AAV and TD were confirmed by medical record review. Person-years (PY) of follow-up were calculated from AAV diagnosis to the earliest of TD, death or the end of study. Cox-regression analysis was employed to study predictors of TD.

RESULTS

At AAV diagnosis, 100 individuals (15.5%, 77 females) had TD, 59 had myeloperoxidase (MPO)-ANCA+ and 34 had proteinase-3 (PR3)-ANCA+. Patients with TD tended to have lower C reactive protein, lower haemoglobin and fewer constitutional symptoms. Survival and renal survival was greater in those patients with AAV with pre-existing TD. During 4522 PY of follow-up, a further 29 subjects developed TD, yielding an incidence rate of 641/100 000 PY. No analysed factor predicted de novo TD in AAV. The prevalence of TD among patients with AAV in southern Sweden was 18%.

CONCLUSION

TD is a common comorbidity in AAV, affecting nearly one in five. While TD diagnosis is more common in females and MPO-ANCA+, these factors do not predict de novo TD after initiation of AAV treatment, necessitating monitoring of all patients with AAV with respect to this comorbidity.

The Effect of Vitamin D Supplementation on Hypothyroidism in the Randomized Controlled D-Health Trial

Background: Hypothyroidism is common, and in iodine-sufficient areas, it is primarily caused by autoimmune destruction of the thyroid gland. Observational studies have consistently shown an inverse association between serum 25-hydroxyvitamin D concentration and autoimmune diseases; however, there is a lack of evidence from randomized controlled trials to support a benefit of vitamin D supplementation, particularly for autoimmune thyroid diseases. We, therefore, aimed to assess the effect of vitamin D supplementation on the incidence of hypothyroidism. Methods: We analyzed data from the D-Health Trial (n = 21,315), a randomized double-blind placebo-controlled trial of 60,000 international units per month of supplemental vitamin D3 among Australians aged 60 years and over. Hypothyroidism, a tertiary outcome of the D-Health Trial, was defined by treatment with levothyroxine, ascertained through linkage with the Australian Pharmaceutical Benefits Scheme. The outcome was time to first prescription of levothyroxine. We began follow-up at 12 months after randomization; people who had died or who had been dispensed levothyroxine during the first year were excluded. Flexible parametric survival models were used to assess the effect of vitamin D supplementation on hypothyroidism, overall and within strata defined by age, sex, body mass index, and predicted baseline vitamin D status. Results: We included 17,851 participants in the main analysis (vitamin D = 8939; placebo = 8912). During a median follow-up of 4.1 years (interquartile range 4.1-4.1), 293 participants developed hypothyroidism (vitamin D = 138 [1.5%]; placebo = 155 [1.7%]). Vitamin D supplementation did not significantly reduce the incidence of hypothyroidism (overall hazard ratio [HR] 0.89; 95% confidence interval [CI] 0.71-1.12). There was some suggestion of an effect in females (overall HR 0.78; CI 0.58-1.06) but not in males (overall HR 1.06; CI 0.74-1.50; p interaction 0.20). Conclusions: Vitamin D supplementation did not reduce the incidence of hypothyroidism overall; however, the possible beneficial effect observed in females warrants further investigation. Clinical Trial Registration: Australian New Zealand Clinical Trials Registry: ACTRN12613000743763.

Sex differences in lung cancer treatment and outcomes at a large hybrid academic-community practice

Introduction

Methods

Results

Conclusions

Yearly Incidence of Stroke and Bleeding in Atrial Fibrillation with Concomitant Hyperthyroidism: A National Discharge Database Study

Background: Hyperthyroidism is associated with atrial fibrillation (AF), and the latter is a major risk factor for stroke. Aim: We aimed to investigate the yearly incidence of stroke and bleeding in AF patients with and without concomitant hyperthyroidism from the French National Hospital Discharge Database. Methods: Admissions with AF between January 2010 and December 2019 were retrospectively identified and retrieved from the French national database. Incidence rates of ischaemic stroke and bleeding were compared in AF patients with and without concomitant hyperthyroidism. The associations of risk factors with ischaemic stroke were assessed by Cox regression. Results: Overall 2,421,087 AF patients, among whom 32,400 had concomitant hyperthyroidism were included in the study. During the follow-up (mean: 2.0 years, standard deviation SD: 2.2 years), the yearly incidence of ischaemic stroke was noted to be 2.6 (95% confidence interval CI: 2.5−2.8) in AF patients with concomitant hyperthyroidism, and 2.3 (95%CI: 2.3−2.4) in non-thyroid AF patients. Hyperthyroidism was noted as an independent risk factor for ischaemic stroke (adjusted hazard ratio aHR: 1.133, 95%CI: 1.080−1.189) overall, particularly within the first year of hyperthyroidism diagnosis (aHR 1.203, 95%CI 1.120−1.291), however, the association became non-significant in subsequent years (aHR 1.047, 95%CI 0.980−1.118). Major bleeding incidence was lower in the hyperthyroid AF group in comparison to the non-thyroid AF group (incidence ratio: 5.1 vs. 5.4%/year, p < 0.001). The predictive value of CHA2DS2VASc and HAS-BLED scores for ischaemic stroke and bleeding events, respectively, did not differ significantly between AF patients with or without concomitant hyperthyroidism. Conclusions: Hyperthyroidism seems to be an independent risk factor of ischaemic stroke in AF patients, particularly within the first year of hyperthyroidism diagnosis.

Thyrotoxic periodic paralysis (TPP): assessment in the emergency department

A male patient aged in his early twenties presented to the emergency department (ED) with quadriparesis. He was ordinarily fit and well and had exercised and eaten a carbohydrate rich meal the evening before. His point-of-care venous blood sample on arrival to the ED showed hypokalaemia of 1.6 mmol/L. (normal range=3.5-5.0 mmol/L). He was put on a cardiac monitor and started on an intravenous infusion of potassium chloride. With the benefit of hindsight, his male sex, particular features in his history and his initial ECG all pointed to a differential diagnosis of thyrotoxic periodic paralysis (TPP), although a differential diagnosis of a first attack of familial hypokalaemic paralysis was considered. As urgent thyroid function tests were sent promptly, there was minimal delay in reaching a diagnosis of TPP and promptly starting propranolol as a safe and more effective means of reversing TPP, followed by definitive treatment with carbimazole.

Incidence of thyroid diseases: Results from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

OBJECTIVE

To evaluate incidence of subclinical and overt hyperthyroidism and hypothyroidism.

METHODS

The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is a prospective cohort study of 15,105 civil servants, examined at baseline and over a 4-year follow-up. This analysis included 9,705 participants with normal thyroid function at baseline, follow-up information about thyroid function and with no report of using drugs that may interfere in the thyroid function. Thyroid function was defined by TSH/FT4 levels or routine use of thyroid hormones/anti-thyroid medications. Annual and cumulative (over 4-year) incidence rates were presented as percentages (95% Confidence Intervals).

RESULTS

The incidence of all overt and subclinical thyroid disease was 6.7% (1.73%/year): 0.19% for overt hyperthyroidism (0.048%/year), 0.54% for subclinical hyperthyroidism (0.14%/year), 1.98% for overt hypothyroidism (0.51%/year), and 3.99% for subclinical hypothyroidism (1.03%/year). The incidence of all thyroid diseases was higher in women, when compared to men, with a low women:men ratio (1.36). For Blacks the highest incidence was for overt hyperthyroidism, while for Whites, the highest incidence was for overt hypothyroidism. However, the highest incidence of overt hyperthyroidism was detected in Asian descendants. The presence of antithyroperoxidase antibodies at baseline was associated with higher incidence of overt thyroid diseases.

CONCLUSION

These results showed a high incidence of hypothyroidism, which is compatible with a country with a more-than-adequate iodine intake. The low women:men ratio of the incidence of thyroid dysfunction highlights the importance of the diagnosis of thyroid diseases among men in Brazil.

Hyperthyroidism in adolescents

The term 'hyperthyroidism' refers to a form of thyrotoxicosis due to inappropriate high synthesis and secretion of thyroid hormone(s) by the thyroid. The leading cause of hyperthyroidism in adolescents is Graves' disease (GD); however, one should also consider other potential causes, such as toxic nodular goitre (single or multinodular), and other rare disorders leading to excessive production and release of thyroid hormones. The term 'thyrotoxicosis' refers to a clinical state resulting from inappropriate high thyroid hormone action in tissues, generally due to inappropriate high tissue thyroid hormone levels. Thyrotoxicosis is a condition with multiple aetiologies, manifestations, and potential modes of therapy. By definition, the extrathyroidal sources of excessive amounts of thyroid hormones, such as iatrogenic thyrotoxicosis, factitious ingestion of thyroid hormone, or struma ovarii, do not include hyperthyroidism. The aetiology of hyperthyroidism/and thyrotoxicosis should be determined. Although the diagnosis is apparent based on the clinical presentation and initial biochemical evaluation, additional diagnostic testing is indicated. This testing should include: (1) measurement of thyroid-stimulating hormone receptor (TSHR) antibodies (TRAb); (2) analysis of thyroidal echogenicity and blood flow on ultrasonography; or (3) determination of radioactive iodine uptake (RAIU). A 123I or 99mTc pertechnetate scan is recommended when the clinical presentation suggests toxic nodular goitre. A question arises regarding whether diagnostic workup and treatment (antithyroid drugs, radioiodine, surgery, and others) should be the same in children and adolescents as in adults, as well as whether there are the same goals of treatment in adolescents as in adults, in female patients vs in male patients, and in reproductive or in postreproductive age. In this aspect, different treatment modalities might be preferred to achieve euthyroidism and to avoid potential risks from the treatment. The vast majority of patients with thyroid disorders require life-long treatment; therefore, the collaboration of different specialists is warranted to achieve these goals and improve patients' quality of life.

Polymorphism in INSR Locus Modifies Risk of Atrial Fibrillation in Patients on Thyroid Hormone Replacement Therapy

AIMS

Atrial fibrillation (AF) is a risk for patients receiving thyroid hormone replacement therapy. No published work has focused on pharmacogenetics relevant to thyroid dysfunction and AF risk. We aimed to assess the effect of L-thyroxine on AF risk stratified by a variation in a candidate gene.

METHODS AND RESULTS

A retrospective follow-up study was done among European Caucasian patients from the Genetics of Diabetes Audit and Research in Tayside Scotland cohort (Scotland, United Kingdom). Linked data on biochemistry, prescribing, hospital admissions, demographics, and genetic biobank were used to ascertain patients on L-thyroxine and diagnosis of AF. A GWAS-identified insulin receptor-INSR locus (rs4804416) was the candidate gene. Cox survival models and sensitivity analyses by taking competing risk of death into account were used. Replication was performed in additional sample (The Genetics of Scottish Health Research register, GoSHARE), and meta-analyses across the results of the study and replication cohorts were done. We analyzed 962 exposed to L-thyroxine and 5,840 unexposed patients who were rs4804416 genotyped. The rarer G/G genotype was present in 18% of the study population. The total follow-up was up to 20 years, and there was a significant increased AF risk for patients homozygous carriers of the G allele exposed to L-thyroxine (RHR = 2.35, P = 1.6e-02). The adjusted increased risk was highest within the first 3 years of exposure (RHR = 9.10, P = 8.5e-04). Sensitivity analysis yielded similar results. Effects were replicated in GoSHARE (n = 3,190).

CONCLUSION

Homozygous G/G genotype at the INSR locus (rs4804416) is associated with an increased risk of AF in patients on L-thyroxine, independent of serum of free thyroxine and thyroid-stimulating hormone serum concentrations.

Prevalence of autoimmune disorders among bladder pain syndrome patients' relatives

PURPOSE

Possible genetic background and autoimmune etiology of Bladder Pain Syndrome (BPS, formerly Interstitial Cystitis, IC) has been suggested. We studied whether familial clustering of BPS, other autoimmune diseases or fibromyalgia exist among BPS patients' genetically close relatives; possibly reflecting some common predisposing genetic background of these diseases.

MATERIALS AND METHODS

Altogether 420 first- or second-degree relatives of 94 BPS patients fulfilling the NIDDK criteria were asked to fill in a survey on the self-reported diagnosis of urinary tract diseases, fibromyalgia and 23 autoimmune diseases, together with filling the O'Leary-Sant symptom score. The ones with high symptom scores were interviewed and, if necessary, referred to a further clinical consultation. The prevalence of other diseases was compared to previously published prevalence percentages.

RESULTS

334 (80%) of 420 family members returned the questionnaire. Only one of the relatives fulfilled the NIDDK criteria, and one sibling pair among the original BPS patients was found. Asthma, ulcerative colitis, fibromyalgia, iritis and rheumatoid arthritis were more common in the study population than in the reference populations. The reported prevalence of atopic dermatitis and rhinoconjunctivitis causing allergies were lower. In addition, the results show that the O'Leary-Sant symptom score is not reliable in screening for new BPS cases.

CONCLUSIONS

Our study suggests that in BPS patients' families, fibromyalgia and autoimmune diseases including asthma, and especially the non-allergic form of asthma, may be over-represented.

An Intronic HCP5 Variant Is Associated With Age of Onset and Susceptibility to Graves Disease in UK and Polish Cohorts

CONTEXT

The genetic background of young-onset Graves disease (GD) remains largely unknown. An intronic variant in human leukocyte antigen (HLA) complex P5 (HCP5) has previously been associated with GD susceptibility and age of onset in a cohort of Polish patients.

OBJECTIVE

We aimed to investigate the association of the HCP5 variant rs3094228 with GD susceptibility and age of onset in a UK cohort and conduct a meta-analysis of UK and Polish data.

DESIGN AND PARTICIPANTS

rs3094228 was genotyped in 469 UK patients with GD using Taqman chemistry. Genotype frequencies were compared with genotypic data available from the Wellcome Trust case-control consortium using logistic regression analysis. To determine whether rs3094228 is independently associated with age of GD onset, the HLA DRB1*0301 tagging variant, rs535777, was also genotyped.

RESULTS

The C allele of rs3094228 was overrepresented in the UK GD cohort compared with controls (P allele=5.08 × 10-9, odds ratio 1.76; [95% confidence interval, 1.46-2.13]). This association was more marked in young-onset GD (<30 years) (P allele=1.70 × 10-10 vs P allele=0.0008). The meta-analysis of UK and Polish data supported the association of the C allele with GD susceptibility (P allele=1.79 × 10-5) and age of onset (P allele=5.63 × 10-8). Haplotype analysis demonstrated that rs3094228 is associated with age of GD onset (P = 2.39 × 10-6) independent of linkage disequilibrium with HLA DRB1*0301.

CONCLUSION

The rs3094228 HCP5 polymorphism is independently associated with GD susceptibility and age of onset in a UK GD cohort. Our findings indicate a potential role of long noncoding ribonucleic acids, including HCP5, in GD pathogenesis, particularly in the younger population.

Pharmacokinetic bias analysis of an association between clinical thyroid disease and two perfluoroalkyl substances

Exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) has been associated with the occurrence of thyroid disease in some epidemiologic studies. We hypothesized that in a specific epidemiologic study based on the National Health and Nutrition Examination Survey, the association of clinical thyroid disease with serum concentration of PFOA and PFOS was due to reverse causality. Thyroid hormone affects glomerular filtration, which in turn affects excretion of PFOA and PFOS. We evaluated this by linking a model of thyroid disease status over the lifetime to a physiologically based pharmacokinetic model of PFOA and PFOS. Using Monte Carlo methods, we simulated the target study population and analyzed the data using multivariable logistic regression. The target and simulated populations were similar with respect to age, estimated glomerular filtration rate, serum concentrations of PFOA and PFOS, and prevalence of clinical thyroid disease. The analysis showed little or no evidence of bias from the hypothesized mechanism. The largest bias was for the fourth quartile of PFOA in females, with an odds ratio of 0.93 (95% CI, 0.90, 0.97). The reported odds ratio of clinical thyroid disease for this group was 1.63 (1.07, 2.47), and if it were corrected for the bias would have been 1.74 (1.14, 2.65). Our results suggest that little of the reported association in the target study was due to reverse causality.

Prevalence and incidence of thyroid dysfunction in type 1 diabetes, type 2 diabetes and latent autoimmune diabetes of adults: The Fremantle Diabetes Study Phase II

OBJECTIVE

Since the results of published studies assessing thyroid dysfunction complicating diabetes have been variable in quality, inconsistent and may not reflect contemporary clinical care, the aim of this study was to determine its prevalence and incidence in a large, well-characterized, representative cohort.

DESIGN

Community-based, longitudinal, observational study.

PATIENTS

A total of 1617 participants from the Fremantle Diabetes Study Phase II (FDS2), including 130 (8.0%) with type 1 diabetes, 1408 (87.1%) with type 2 diabetes, and 79 (4.9%) with latent autoimmune diabetes of adults (LADA).

MEASUREMENTS

Serum thyrotropin (TSH) and free thyroxine (FT4) at baseline between 2008 and 2011 and in those attending Year 4 follow-up.

RESULTS

The prevalence of known thyroid disease (ascertained from baseline self-reported thyroid medication use or hospitalization data) was 11.7% (189/1617). Of the remaining 1428 participants, 5.1% (73/1428) had biochemical evidence of subclinical hypothyroidism, 1.1% (15/1428) overt hypothyroidism, 0.1% (2/1428) subclinical hyperthyroidism and 0.2% (3/1428) overt hyperthyroidism, representing an overall baseline prevalence of thyroid disease of 17.4% (282/1617). During 5694 patient-years of follow-up, 25 (3.0%) of the 844 with a normal baseline TSH and follow-up data developed known thyroid disease. Of the remaining 819, 3.4% developed subclinical hypothyroidism, 0.2% overt hypothyroidism and 0.5% subclinical hyperthyroidism. There were no statistically significant differences in the prevalence or incidence of thyroid dysfunction by diabetes type.

CONCLUSIONS

Thyroid dysfunction, known or detected through screening, is common in diabetes. These data suggest the need for periodic clinical and biochemical screening for thyroid disease in all types of diabetes.

Color discrimination assessment in patients with hypothyroidism using the Farnsworth-Munsell 100 hue test

There is evidence in the literature that hypofunction of the thyroid gland (hypothyroidism) affects color vision in rodents by influencing the production of the visual pigment opsin. The effect of hypothyroidism on color vision in humans has not been examined in any great detail. In this cross-sectional study we evaluated color discrimination using the Farnsworth-Munsell 100 hue test (FM-100 test) in 25 individuals with pre-treatment hypothyroidism (mean age ${38}\;{\pm }\;{9}.{2}\;\text{yr}$38±9.2yr), and a control euthyroid group, ${ n} ={26}$n=26 (mean age ${39.6}\;{\pm }\;{8}.{4}\;\text{yr}$39.6±8.4yr). There was no statistically significant difference in the total error score ($\surd{\text{TES}}$√TES) between the groups, but the hypothyroid group had a significantly greater partial error score ($\surd{\text{PES}}$√PES) along the blue-yellow (B-Y) axis compared to the red-green (R-G) axis. No statistically significant differences in B-Y and R-G PES were observed in the control group. This study shows that hypothyroidism affects color vision in humans, causing significant impairment in the B-Y color subsystem.

Levothyroxine prescriptions trends may indicate a downtrend in prescribing

BACKGROUND

There has been a trend for increased prescribing of levothyroxine (LT4) in many countries, including the United States. Several different factors have been suggested to be the cause of this practice pattern. These factors include increased size of the United States population, more diagnosis of hypothyroidism, more treatment of minimally elevated thyroid-stimulating hormone (TSH) levels, more use of LT4 in older patients, and use of LT4 for treatment of euthyroid patients with non-thyroidal conditions.

METHODS

The electronic databases of the MedStar Health system operating in the Washington, DC and Maryland areas were interrogated to determine the number of patients who were being prescribed levothyroxine during the time period 2008-2016, the number of prescriptions supplied to these individuals, the associated diagnosis, and whether the prescriptions were new or existing prescriptions. Regression analyses were also performed to determine the prescribing trends during this time period.

RESULTS

Although the annual number of levothyroxine prescriptions increased during this time period, the percentage of patients in the database receiving levothyroxine for hypothyroidism initially increased and then decreased over time (2.5% to 3.2% to 2.5%). The percentage of prescriptions written for patients who did not appear to carry a diagnosis of hypothyroidism steadily declined (3.5% to 1.0%). Although the percentage of patients with existing prescriptions for hypothyroidism initially increased and then were maintained at steady levels (1.4% to 2.4% to 2.2%), a smaller percentage of patients with existing prescriptions were documented over time when there was no diagnosis of hypothyroidism (1.45% to 0.89%). The percentage of patients with new prescriptions declined over time for all groups. The number of annual 90-day period prescriptions increased over the time for patients with a diagnosis of hypothyroidism, but down-trended starting over the latter part of the time period for those patients without a diagnosis of hypothyroidism.

CONCLUSION

Taken together, these data suggest that there may be a stabilization, and even a down-trend in levothyroxine prescribing with the MedStar system. The decrease in levothyroxine prescribing appears to be accounted for by less use of levothyroxine without an established diagnosis of hypothyroidism, and less initiation of new prescriptions.

THYROID HORMONES AS A THIRD LINE OF AUGMENTATION MEDICATION IN TREATMENT-RESISTANT DEPRESSION

Introduction

Clinical or subclinical hypothyroidism dictates the severity of depressive episodes and more frequently overlaps psychotic phenomenology. There are also major depressive episodes resistant to treatment in patients with euthyroidism, in which supplementation of antidepressant medication with thyroid hormones is beneficial.

Material

Systematization of meta-analyses from perspectives: hypothyroidism and depression, autoimmune and depression pathology, gestational and puerperal pathology in association with hormonal and dispositional changes, presentation of therapeutic schemes.

Results

Hypothyroidism is more commonly comorbid with major depression in women. It associates the need for hospitalizations, psychotic phenomenology, resistance to treatment, somatic comorbidities. Autoimmune pathology is associated with depression and requires thorough investigation. A possible genetic candidate for thyroid dysfunction is the DIO1 gene. FT4 may be a predictor, but the combination of FT4 + TBG measured during the prenatal period has a higher prognostic power for a future depressive episode.

Conclusion

The article presents psychiatric medication schemes that combine antidepressants and antipsychotics of various classes with other enhancers, an important role going back to step three, which includes thyroid hormones, mainly T3. The doses used are smaller than the amount of endogenous production of T3 daily, with a small risk of inducing clinical hyperthyroidism.

Association between the Occurrence of Primary Hypothyroidism and the Exposure of the Population Near to Industrial Pollutants in São Paulo State, Brazil

Background: Environmental agents interfere with thyroid function at multiple levels. This study was to investigate the association between pollutant concentrations and the primary hypothyroidism (PH) occurrence odds in residents living in the Capuava Petrochemical Complex (CPC) influence area. Methods: This area was evaluated with the combination of the AERMOD dispersion model with the Weather Research Forecast (WRF) meteorological model (2016). The concentration of atmospheric pollutants were analyzed in 2017 using meteorological data on the period from 2005 to 2009, correlating this data with the research done in 2003 to 2005. A home-based questionnaire was applied to evaluate 2004 residents, of both sexes, aged from 8 to 72 years, based on their proximity to the industrial areas; were select residents with PH. Results: Volatile organic compounds (VOCs), carbon monoxide (CO), and nitrogen dioxide (NO₂) concentrations presented the highest correlations between the PH odds and pollutant concentrations. Conclusion: Air pollution associated with the presence of the CPC is an important environmental factor contributing to the development of PH in the nearby population. As the first study showing this association in Brazil, research should be continued to better understand the mechanisms and to find ways to compensate for or remedy to avoid health impacts in future populations.

A model of functional thyroid disease status over the lifetime

Mathematical models of the natural history of disease can predict incidence rates based on prevalence data and support simulations of populations where thyroid function affects other aspects of physiology. We developed a Markov chain model of functional thyroid disease status over the lifetime. Subjects were in one of seven thyroid disease states at any given point in their lives [normal, subclinical hypothyroidism, overt hypothyroidism, treated thyroid disease (ever), subclinical hyperthyroidism, overt hyperthyroidism, and reverted to normal thyroid status]. We used a Bayesian approach to fitting model parameters. A priori probabilities of changing from each disease state to another per unit time were based on published data and summarized using meta-analysis, when possible. The probabilities of changing state were fitted to observed prevalence data based on the National Health and Nutrition Examination Survey 2007–2012. The fitted model provided a satisfactory fit to the observed prevalence data for each disease state, by sex and decade of age. For example, for males 50–59 years old, the observed prevalence of ever having treated thyroid disease was 4.4% and the predicted value was 4.6%. Comparing the incidence rates of treated disease predicted from our model with published values revealed that 82% were within a 4-fold difference. The differences seemed to be systematic and were consistent with expectation based on national iodine intakes. The model provided new and comprehensive estimates of functional thyroid disease incidence rates for the U.S. Because the model provides a reasonable fit to national prevalence data and predicts thyroid disease status over the lifetime, it is suitable for simulating populations, thereby making possible quantitative bias analyses of selected epidemiologic data reporting an association of thyroid disease with serum concentrations of environmental contaminants.

Annual Incidence of Thyroid Disease in Patients Who First Time Visit Department for Thyroid Diseases in Tuzla Canton

AIM

The aim of this paper was to evaluate the incidence of thyroid gland diseases in relation to age, sex, existing associated symptoms and thyroxine and thyroid-stimulating hormone levels, in correlation with morphological characteristics and corresponding clinical diagnosis for thyroid gland.

METHODS

Retrospective research was conducted in the period 1-Dec-2017 to 31-Dec-2017 and included a total of 500 subjects of both sexes aged 1 to 80 years. All subjects had clinical examination, which included anamnestic data, palpatory examination of thyroid gland, as well as functional status of thyroid gland.

RESULTS

The results of the research have shown that majority of subjects were females (78.6% vs. 21.4%). The largest number of subjects was in the age group 41 to 60 years. The average age of females was 43.22 years and 42.86 for males. The most common associated symptom for both sexes was related to cardiovascular system disorder (61.2%). Subclinical hypothyroidism was the most prevalent thyroid gland disease (12.8%), while diffuse enlargement of thyroid gland (4.60 %) was the most common in morphological classification. The mean value for free thyroxine for the overall sample was 14.39 pmol/L and 3,4 mlU/L for thyroid-stimulating hormone. Thyroid-stimulating hormone levels were highest in the age group 41-60 years (p=0.043).

CONCLUSION

The overall incidence of thyroid gland diseases was 18.57% for females and 13.08% for males. Free thyroxine levels were highest in thyroid gland with nodular changes and subclinical hypothyroidism (p=0.0001). Thyroid-stimulating hormone levels had the highest value in a thyroid gland with diffuse changes and subclinical hypothyroidism (p=0.0001).

Prevalence of Undiagnosed Hypothyroidism in Europe: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with undiagnosed hypothyroidism are not treated for the disease and are at high risk of developing serious complications, with major impact on public health. There is a need to systematically review the available evidence on this topic.

OBJECTIVE

To identify the prevalence of undiagnosed hypothyroidism in Europe.

METHODS

A systematic review of the literature (Medline, EMBASE, and Cochrane Central) was performed to identify epidemiological studies on the prevalence of undiagnosed hypothyroidism among European populations published between January 2008 and April 2018. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. Random-effects meta-analyses were performed to pool estimates of proportions (with 95% confidence intervals [CIs]) of undiagnosed (1) subclinical, (2) overt, and (3) total hypothyroidism.

RESULTS

The search returned 15,565 citations (4,526 duplicates). Twenty papers were included in the study. Fourteen and 6 studies were of good and moderate methodological quality, respectively. The results of the meta-analyses were as follows for the prevalence of undiagnosed hypothyroidism: subclinical, 4.11% (95% CI 3.05-5.31%, I2 = 99.32%); overt, 0.65% (95% CI 0.38-0.99%, I2 = 96.67%); and total, 4.70% (95% CI 2.98-6.79%, I2 = 99.53%). According to the sensitivity analysis, the prevalence of hypothyroidism tends to be higher in female patients, in those aged ≥65 years, among studies with lower sample sizes, in those with thyroid-stimulating hormone levels <4.5 mIU/L, and in Eastern and Southern Europe.

CONCLUSIONS

The current evidence suggests that a considerable proportion of the European population has hypothyroidism, particularly subclinical hypothyroidism, which is undiagnosed. This issue deserves further investigation because of possible deleterious consequences for public health.

Trends, Determinants, and Associations of Treated Hypothyroidism in the United Kingdom, 2005-2014

BACKGROUND

Recent reports suggest that prescriptions for thyroid hormones have increased. Recent trends in and determinants of the prevalence of treated hypothyroidism across the United Kingdom were therefore analyzed.

METHODS

Data covering the whole of the United Kingdom held by the National Health Service and the Office of National Statistics were examined. The main outcome measured was trends in the prevalence of treated hypothyroidism between 2005 and 2014. In addition, linear trend forecasting was performed to estimate projected trends in the prevalence of treated hypothyroidism up to the year 2025. Furthermore, determinants of variation of treated hypothyroidism prevalence across each of the 237 health areas in the United Kingdom in 2014 and its association with other health conditions were explored by multivariate linear regression analyses.

RESULTS

The prevalence of treated hypothyroidism increased from 2.3% (1.4 million) to 3.5% (2.2 million) of the total British population between the years 2005 and 2014 and is projected to rise further to 4.2% (2.9 million) by 2025. There was large geographical variation of treated hypothyroidism across the United Kingdom, with London having the lowest (1.4%) and the Western Isles of Scotland having the highest (6.3%) prevalence. This variation was attenuated, but did not completely disappear, after some potential determinants were accounted for. The prevalence of treated hypothyroidism was independently related to health areas, with a higher proportion of individuals who were female, white, and obese, and negatively associated with prevalent cigarette smoking. The prevalence of treated hypothyroidism was significantly associated with the frequency of prevalent atrial fibrillation but not with other major health conditions, including ischemic heart disease and osteoporosis.

CONCLUSIONS

Between 2005 and 2014, the prevalence of treated hypothyroidism increased across the United Kingdom, has wide geographical variation, and is likely to increase further for the foreseeable future. Clinical effects and cost-effectiveness of the trend in increasing treatment of hypothyroidism remains to be evaluated.

Pattern visual evoked potential in hypothyroid patients

PURPOSE

To investigate the functional integrity of visual pathway in hypothyroid patients by pattern visual evoked potential (PVEP).

METHODS

We enrolled 36 female patients with history of hypothyroidism (18 overt and 18 subclinical) aged 20 to 60 years and 36 healthy women of similar age (control group). All subjects had a complete ophthalmic examination. For VEP testing, subjects were exposed to checks subtending a visual angle of 15 and 60 min of arc.

RESULTS

For the 15 min of arc check size, the mean P100 latency was significantly delayed (113 milliseconds (ms)) and amplitude significantly reduced (9.2 microvolts (µv)) in the hypothyroidism group compared with controls (109.6 ms and 11.6 µv, respectively). For this 15' check size, the group differences were related to significantly increased latency and reduced amplitude of responses in the group with overt hypothyroidism compared with controls. There was no difference between the groups (hypothyroid vs control) with 60 min of arc check size. There was a significant correlation between severity of the disease and PVEP component.

CONCLUSIONS

In conclusion, low levels of circulating hypothyroid hormone are associated with delay in the pattern VEP to small check sizes. This CNS involvement worsens in patients with greater severity and duration of hypothyroidism.

Adjuvant rituximab, a potential treatment for the young patient with Graves' hyperthyroidism (RiGD): study protocol for a single-arm, single-stage, phase II trial

INTRODUCTION

Graves' disease (Graves' hyperthyroidism) is a challenging condition for the young person and their family. The excess thyroid hormone generated by autoimmune stimulation of the thyroid stimulating hormone receptor on the thyroid gland can have a profound impact on well-being. Managing the young person with Graves' hyperthyroidism is more difficult than in older people because the side effects of conventional treatment are more significant in this age group and because the disease tends not to resolve spontaneously in the short to medium term. New immunomodulatory agents are available and the anti-B cell monoclonal antibody rituximab is of particular interest because it targets cells that manufacture the antibodies that stimulate the thyroid gland in Graves'.

METHODS AND ANALYSIS

The trial aims to establish whether the combination of a single dose of rituximab (500 mg) and a 12-month course of antithyroid drug (usually carbimazole) can result in a meaningful increase in the proportion of patients in remission at 2 years, the primary endpoint. A single-stage, phase II A'Hern design is used. 27 patients aged 12-20 years with newly presenting Graves' hyperthyroidism will be recruited. Markers of immune function, including lymphocyte numbers and antibody levels (total and specific), will be collected regularly throughout the trial.

DISCUSSION

The trial will determine whether the immunomodulatory medication, rituximab, will facilitate remission above and beyond that observed with antithyroid drug alone. A meaningful increase in the expected proportion of young patients entering remission when managed according to the trial protocol will justify consideration of a phase III trial.Ethics and dissemination The trial has received a favourable ethical opinion (North East - Tyne and Wear South Research Ethics Committee, reference 16/NE/0253, EudraCT number 2016-000209-35). The results of this trial will be distributed at international endocrine meetings, in the peer-reviewed literature and via patient support groups.

TRIAL REGISTRATION NUMBER

ISRCTN20381716.

Epidemiology of hyperthyroidism in Iran: a systematic review and meta-analysis

Background

Hyperthyroidism is a systemic disorder that causes severe morbidity and is even fatal. Several studies have been performed in Iran to determine the epidemiologic properties of hyperthyroidism; however, they did not use a systematic approach or meta-analysis to evaluate the results. Therefore, this systematic review and meta-analysis aimed to evaluate the epidemiologic data on hyperthyroidism in Iran.

Methods

In order to find all relevant papers published by October 2017, we searched both international (Web of Science, Scopus, PubMed, Embase, and Cochrane library) and Persian databases (Scientific Information Database, Magiran, and Barekat Knowledge Network System). Meta-analysis was performed using metaprop random effects analysis for prevalence and metaprop fix effect analysis for incidence by Stata statistical software. I² was used for the demonstration of heterogeneity.

Results

Of 7667 published papers or conference proceeding, 7448 studies were removed after eliminating duplicates and reviewing titles/abstracts. Finally, after reviewing 219 full texts, 18 papers met the inclusion and exclusion criteria. The pooled prevalence of total, overt, and subclinical hyperthyroidism in general population were 2.43% (95% CI: 0.23-4.63%), 0.69% (95% CI: 0.21-1.18%), and 1.52% (95% CI: 0.14-2.89%), respectively. The pooled annual incidence of total hyperthyroidism was 2.2 (95% CI: 1.1-3.3) per 1000 population: 0.8 (0.1-1.4) and 1.3 (0.4-2.2) per 1000 population for overt and subclinical hyperthyroidism, respectively.

Conclusions

This is the first systematic review and meta-analysis, which investigated the epidemiology of hyperthyroidism in Iran. It seems that the prevalence and incidence of hyperthyroidism among the general population in Iran is similar to that in other parts of the world.

Prevalence of thyroid dysfunction in a Large Southern European Population. Analysis of modulatory factors. The APNA study

CONTEXT

To study the prevalence of thyroid dysfunction in a very large unselected population.

OBJECTIVE

To determine the prevalence of abnormal thyroid function and evaluate potential modulatory factors.

DESIGN AND SETTING

The Estudio de Atención Primaria de Navarra, The APNA Study, is a cross-sectional study conducted in northern Spain. It involved 303 883 people, of 20 years of age and older, who live in the Navarra region. Participants are covered by the public healthcare system and medical records are digitalized.

MAIN OUTCOME MEASURES

The information was gathered from e-registered data regarding serum thyrotropin (TSH), thyroid hormones, thyroid antibody concentration and clinical context. Measurements were logged (demographic information and potential thyroid function modulatory factors).

RESULTS

Serum TSH (mU/L) normal range was established at 0.7-4.28. At the time of the study, 87% of the Navarra population had a TSH level within the normal range. Mean serum TSH in euthyroid individuals was higher in women (2.15) than in men (1.96) (P < .001) and higher in the obese with body mass index (BMI) ≥30 kg/m² (2.12) as compared to the non-obese BMI <30 kg/m² (2.06) (P < .001). Mean TSH for the entire population was 1.9. The native Spanish population had statistically significantly lower TSH (1.87) than non-native Spanish (2.15) (P < .001). Additionally, we observed that serum TSH levels decreased with age and an increase in the prevalence of hypothyroidism in the elderly and among people with low-income levels. The prevalence of thyroid dysfunction in Navarra was 12.3%. The prevalence of hypothyroidism (or high TSH) in the population was 8.8% (13.3% in women, 4.2% in men), and the prevalence of hyperthyroidism (or low TSH) was 4.3% (5.6% in women, 3.0% in men).

CONCLUSIONS

Nearly 15% of the general population suffers from biochemical thyroid dysfunction. The serum TSH level appears to be influenced by sex, BMI, age, ethnic origin and socio-economic status.

Comparison between acute kidney injury (AKI) and non-AKI patients secondary to severe hypothyroidism

Hypothyroidism was a rare cause of rhabdomyolysis, which finally progressed to acute kidney injury (AKI). We compared nine patients with AKI secondary to hypothyroidism and six patients with severe hypothyroidism. Besides creatine kinase, globulin could be an alternative biomarker of rhabdomyolysis related to hypothyroidism.

Global epidemiology of hyperthyroidism and hypothyroidism

Thyroid hormones are essential for growth, neuronal development, reproduction and regulation of energy metabolism. Hypothyroidism and hyperthyroidism are common conditions with potentially devastating health consequences that affect all populations worldwide. Iodine nutrition is a key determinant of thyroid disease risk; however, other factors, such as ageing, smoking status, genetic susceptibility, ethnicity, endocrine disruptors and the advent of novel therapeutics, including immune checkpoint inhibitors, also influence thyroid disease epidemiology. In the developed world, the prevalence of undiagnosed thyroid disease is likely falling owing to widespread thyroid function testing and relatively low thresholds for treatment initiation. However, continued vigilance against iodine deficiency remains essential in developed countries, particularly in Europe. In this report, we review the global incidence and prevalence of hyperthyroidism and hypothyroidism, highlighting geographical differences and the effect of environmental factors, such as iodine supplementation, on these data. We also highlight the pressing need for detailed epidemiological surveys of thyroid dysfunction and iodine status in developing countries.

Replication confirms the association of loci in FOXE1, PDE8B, CAPZB and PDE10A with thyroid traits: a Genetics of Diabetes Audit and Research Tayside study (GoDARTS)

OBJECTIVE

Replication of associations in genome-wide association studies is desirable to ensure that such signals are potentially clinically meaningful. This study aimed to replicate associations of selected single-nucleotide polymorphisms (SNPs) with hypothyroidism and serum thyroid-stimulating hormone (TSH) using electronic medical records (EMRs).

PATIENTS AND METHODS

A cross-sectional study was carried out among patients of European Caucasian ethnicity from the Genetics of Diabetes Audit and Research Tayside recruited in Tayside (Scotland, UK). EMRs (biochemistry, prescribing, hospital admissions and demographics) were used to ascertain patients with hypothyroidism and their controls as well as average serum TSH concentration, and linked to genetic biobank data. Genetic tests of association were performed using logistic and linear regression models.

RESULTS

We analysed 1703 cases of hypothyroidism and 9457 controls. All four SNPs located on chromosome 9 at FOXE1 were associated with hypothyroidism with similar effect estimates (odds ratio=0.75-0.76, P<5e-08). Also, loci on chromosomes 1 (PTPN22), six (HLA-E/HLA-C) and 12 (SH2B3) were replicated. For serum TSH, we confirmed 12 SNPs previously reported at PDE8B, CAPZB, PDE10A, LOC105371356, NR3C2, VEGFA, IGFBP5, INSR, PRDM11, NFIA, ITPK1 and ABO. Overall, these SNPs accounted for 6.8% of the serum TSH variation (P<1e-04).

CONCLUSION

EMRs linked to genomic data in large populations enable validation of genome-wide association studies discoveries without additional genotyping costs. Our replication confirmed at genome-wide significance the association of loci at FOXE1 with hypothyroidism, and PDE8B, CAPZB and PDE10A with serum TSH. A total of 12 SNPs seemed to explain nearly 7% of the serum TSH variation.

Cognitive Function, APOE Gene Polymorphisms, and Thyroid Status Associations in Postmenopausal Women in Poland

BACKGROUND

The objective of the study was to analyze a potential association between cognitive functions and thyroid status in postmenopausal women with different polymorphisms of the apolipoprotein E gene (APOE).

METHODS

The examined population included 402 postmenopausal women from south-eastern Poland. The evaluation of cognitive functions was made with the use of the diagnostic Central Nervous System-Vital Signs equipment (Polish version). Multiplex polymerase chain reactions were performed to assess APOE polymorphisms. The thyroid hormone tests were assessed by an accredited laboratory.

RESULTS AND CONCLUSION

Lower results of cognitive functions were associated with the presence of the ε4 APOE allele in postmenopausal women. The ε4 APOE polymorphism was associated with a higher concentration of thyroid-stimulating hormone and lower concentrations of free triiodothyronine and total triiodothyronine.

Stable Isotope Pharmacokinetic Studies Provide Insight into Effects of Age, Sex, and Weight on Levothyroxine Metabolism

BACKGROUND

This study sought to determine whether levothyroxine pharmacokinetics (PKs) are affected by age, weight, and sex.

METHODS

A PK study was performed after administration of a tracer dose of carbon-13-labeled LT4 (¹³C-LT4). The study was conducted at an academic medical center. Adults of any age being treated with levothyroxine for hypothyroidism were enrolled in the study. A single dose of ¹³C-LT4 was administered. Eighteen serial plasma samples were collected. One sample was obtained before the ¹³C-LT4 dose, and the majority of the remaining samples were collected over the 120-hour period post dosing. ¹³C-LT4 concentration was quantified using liquid chromatography tandem mass spectrometry. PK analysis was conducted using a linear log trapezoidal non-compartmental analysis using Phoenix 6.4.

RESULTS

Eight males and 33 females with a median age of 50 years (range 22-78 years) and median weight of 65.9 kg (range 50-150 kg) were enrolled in the study. The median ¹³C-LT4 dose administered was 100 μg (range 70-300 μg). The median oral clearance rate (CL/F), apparent volume of distribution (V/F), time to peak concentration (T_max), and dose-normalized peak concentration (C_max) of ¹³C-LT4 were estimated to be 0.712 L/h, 164.9 L, 4 h, and 7.5 ng/L/μg, respectively. The dose-normalized area under the concentration-time curve from time 0 to 120 hours and half-life of the terminal distribution phase were 0.931 ng.h/mL/μg and 172.2 h, respectively. There was no significant difference in any ¹³C-LT4 PK parameter between patients aged >60 years (n = 10) and patients aged ≤60 years (n = 31), nor was there a relationship between age as a continuous variable and ¹³C-LT4 PK parameters. Sex only affected CL/F, V/F, and dose-normalized C_max in univariate analyses. However, after adjusting for weight, sex was no longer a significant covariate. Weight was a significant predictor for CL/F, V/F and dose-normalized C_max of ¹³C-LT4 in multivariate analyses.

CONCLUSION

Prior studies suggest that patient age affects levothyroxine dose requirement. This study did not identify an effect of age and suggests that age-related changes in levothyroxine pharmacokinetics may be mediated by age-related weight differences. Physicians should consider a patient's weight, rather than age, for estimating levothyroxine dosage requirement.

Prevalence of treated hypothyroidism in the community: Analysis from general practices in North-East England with implications for the United Kingdom

OBJECTIVE

Hypothyroidism is more frequently diagnosed in women and older individuals. It has been suggested that the prevalence of hypothyroidism and the number of prescriptions for thyroid hormones are increasing. However, despite hypothyroidism being a common medical condition, contemporary data on prevalence, particularly across the various age groups, is limited.

DESIGN

Information regarding number of individuals diagnosed with treated hypothyroidism (defined as patients prescribed levothyroxine) across ten General Practices (total population of 66 843) in the North-East of England in 2016 was obtained in an anonymized manner. Total as well as age group-specific point prevalence rates were calculated. In addition, corresponding population data for the United Kingdom were acquired, and national total and age-specific hypothyroidism prevalence rates were estimated.

RESULTS

The overall prevalence of hypothyroidism in this community sample was 4.5% (n = 3004). Prevalence increased across the age groups from 0.1% in children aged 0-10 years to 15.1% in those aged more than 90 years. After adjusting for demographic differences between the North-East England and UK populations, it is estimated that the total UK-wide prevalence of hypothyroidism in 2016 is 3.6%; affecting more than 2.3 million individuals including nearly 800 000 individuals aged >70 years.

CONCLUSIONS

Hypothyroidism affects millions of individuals in the UK and is currently a prevalent diagnosis in more than 1 in 10 individuals aged above 70 years. As the population ages this number is likely to increase. The clinical and economic effects of current management strategies for hypothyroidism, particularly in the older population, need to be evaluated.

Comparative Efficacy and Toxicity of Different Species of Sargassum in Haizao Yuhu Decoction in PTU-Induced Goiter Rats

BACKGROUND

Haizao Yuhu Decoction has been widely used to treat thyroid-related diseases especially goiter with few side effects in traditional Chinese medicine (TCM), including herb pair Sargassum (HZ) and Glycyrrhizae Radix et Rhizoma (GC), as one of "eighteen antagonistic medicaments." The two different species of Sargassum, Sargassum fusiforme (Sf) and Sargassum pallidum (Sp), are not clearly differentiated in clinical use, so that herb pair Sf-GC and Sp-GC could show different effect and toxicity.

METHODS

We investigated the antigoitrous effect and toxicity and clarified the potential underlying mechanism of the two different species of Sargassum in HYD (HYDf and HYDp) in PTU-reduced goiter rats.

RESULTS

The results demonstrated that both HYDf and HYDp could exhibit antigoitrous effect through alterations in hypothalamus-pituitary-thyroid (HPT) axis and inhibition of the TPO gene expression; there is no difference in the antigoitrous effects between the two different species of Sargassum application in HYD.

CONCLUSION

This study evaluated the safety and efficacy of herb pair HZ-GC applied in HYD in goiter rats at molecular, cellular, and whole level and compared the two species of Sargassum further. We provide a reliable way to clarify the possible mechanism of the antagonistic medicament herb pair HZ-GC for its application.

The microbiota and autoimmunity: Their role in thyroid autoimmune diseases

Since the 1970s, the role of infectious diseases in the pathogenesis of Graves' disease (GD) has been an object of intensive research. The last decade has witnessed many studies on Yersinia enterocolitica, Helicobacter pylori and other bacterial organisms and their potential impact on GD. Retrospective, prospective and molecular binding studies have been performed with contrary outcomes. Until now it is not clear whether bacterial infections can trigger autoimmune thyroid disease. Common risk factors for GD (gender, smoking, stress, and pregnancy) reveal profound changes in the bacterial communities of the gut compared to that of healthy controls but a pathogenetic link between GD and dysbiosis has not yet been fully elucidated. Conventional bacterial culture, in vitro models, next generation and high-throughput DNA sequencing are applicable methods to assess the impact of bacteria in disease onset and development. Further studies on the involvement of bacteria in GD are needed and may contribute to the understanding of pathogenetic processes. This review will examine available evidence on the subject.

Incidence of thyroid dysfunction in an Iranian adult population: the predictor role of thyroid autoantibodies: results from a prospective population-based cohort study

Background

The prevalence of thyroid dysfunction is high in Isfahan, an area of iodine sufficient in Iran. The aim of this study is to investigate the incidence of thyroid dysfunctions in adults of metropolitan Isfahan and to determine the role of thyroid autoantibodies.

Methods

In a population-based cohort study in 2006–2011, we measured TSH, T4, T3, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) in 618 out of 2254 people who were euthyroid in 2006. The incidence rates per 1000 person-year (pr) were calculated. The odds ratio (OR), relative risk (RR), and 95% confidence interval (95% CI) were calculated based on logistic regression to quantify the potential predictors of thyroid dysfunction. The receiver-operator characteristic (ROC) analysis along with area under the curve (AUC) was used to determine the optimal cutoff values for baseline TPOAb and TgAb as predictors of thyroid dysfunction.

Results

Within a 6-year follow-up, the incidence rate of hypothyroidism was 3.3 in women and 2.1 in men while the incidence rate of hyperthyroidism was 3.8 in women and none in men per 1000 (person-year). A cutoff value of TPOAb at 38 IU/mL was obtained to differentiate the patients with hypothyroidism and hyperthyroidism, with specificity of 0.75 and sensitivity of 0.76, and AUC (CI 95%) of 0.882 (0.743–1.02), P = 0.01 and 0.817 (0.600–1.035) P = 0.033, respectively. There is a statistically significant association of hypothyroidism and hyperthyroidism with positive TPOAb [RR (CI 95%): 1.99 (1.27–3.13) and 2.20 (1.23–3.95), respectively].

Conclusions

The incidence rate of thyroid dysfunction is high in Isfahan, and higher TPOAb concentration is its strong predictor.

Thyrotoxicosis - investigation and management

Graves' disease (GD) and toxic nodular (TN) goitre account for most cases of thyrotoxicosis associated with hyperthyroidism. Hyperthyroidism is confirmed with measurement of a suppressed serum thyrotropin concentration (TSH) and elevated free thyroid hormones. The three therapeutic options are antithyroid drugs, radioactive iodine and surgery. Thionamides achieve long-term remission in 35% of cases. Many centres administer fixed doses of iodine-131; larger doses result in improved rates of cure at the cost of hypothyroidism. Surgery is usually considered for patients who have a large goitre, compressive symptoms or significant ophthalmopathy.

Graves' orbitopathy as a rare disease in Europe: a European Group on Graves' Orbitopathy (EUGOGO) position statement

Background

Graves’ orbitopathy (GO) is an autoimmune condition, which is associated with poor clinical outcomes including impaired quality of life and socio-economic status. Current evidence suggests that the incidence of GO in Europe may be declining, however data on the prevalence of this disease are sparse. Several clinical variants of GO exist, including euthyroid GO, recently listed as a rare disease in Europe (ORPHA466682).

The objective was to estimate the prevalence of GO and its clinical variants in Europe, based on available literature, and to consider whether they may potentially qualify as rare. Recent published data on the incidence of GO and Graves’ hyperthyroidism in Europe were used to estimate the prevalence of GO. The position statement was developed by a series of reviews of drafts and electronic discussions by members of the European Group on Graves’ Orbitopathy. The prevalence of GO in Europe is about 10/10,000 persons. The prevalence of other clinical variants is also low: hypothyroid GO 0.02–1.10/10,000; GO associated with dermopathy 0.15/10,000; GO associated with acropachy 0.03/10,000; asymmetrical GO 1.00–5.00/10,000; unilateral GO 0.50–1.50/10,000.

Conclusion

GO has a prevalence that is clearly above the threshold for rarity in Europe. However, each of its clinical variants have a low prevalence and could potentially qualify for being considered as a rare condition, providing that future research establishes that they have a distinct pathophysiology. EUGOGO considers this area of academic activity a priority.

The epidemiology of hyperprolactinaemia over 20 years in the Tayside region of Scotland: the Prolactin Epidemiology, Audit and Research Study (PROLEARS)

OBJECTIVE

To estimate the prevalence and incidence of hyperprolactinaemia. Hyperprolactinaemia is a common problem in endocrine practice, but its epidemiology has not been accurately established.

STUDY DESIGN

A population-based retrospective follow-up study in Tayside, Scotland (population 400,000), from 1993 to 2013.

PATIENTS

Record linkage technology (biochemistry, prescribing, hospital admissions, radiology, mortality and maternity data) was used to identify all patients with a serum prolactin measurement. From these, cases were defined as those with a prolactin greater than 1000 mU/L (47·2 ng/ml) or at least three prescriptions for a dopamine agonist.

MEASUREMENTS

Number of prevalent and incident cases of hyperprolactinaemia per calendar year by age, sex and cause of hyperprolactinaemia.

RESULTS

A total of 32289 patients had a serum prolactin assay undertaken, of which 1301 had hyperprolactinaemia not related to pregnancy: 25·6% patients had pituitary disorder, 45·9% were drug-induced, 7·5% had macroprolactin and 6·1% had hypothyroidism, leaving 15·0% idiopathic. Over the 20 years, there was a fourfold increase in the number of prolactin assays performed, and prevalence of hyperprolactinaemia was initially 0·02%, but rose to 0·23% by 2013. Overall incidence was 13·8 cases per 100000 person-years (20·6 in 2008-13) and was 3·5 times higher in women than in men. The highest rates were found in women aged 25-44 years. Drug-induced causes tripled during the 20 years.

CONCLUSIONS

Rising prevalence of hyperprolactinaemia is probably due to an increased ascertainment and increased incidence of psychoactive drug-related causes. Rates are higher in women than in men but only before the age of 65 years.

Study of Optimal Replacement of Thyroxine in the Elderly (SORTED) - results from the feasibility randomised controlled trial

BACKGROUND

Hypothyroidism is a common condition, particularly in the older population. Thyroid hormone requirements change with age and serum TSH levels also alter, especially in older patients. However, in practice laboratory reference ranges for thyroid function are not age-specific and treatment in older patients aims to achieve a similar target thyroid function level as younger age groups.

METHODS

A dual centre, single blind, randomised controlled trial was conducted to determine the feasibility of a future definitive RCT in hypothyroid individuals aged 80 years or older who were treated with levothyroxine. Potential participants were identified from 17 research-active GP practices (n = 377), by opportunistic invitations (n = 9) or in response to publicity (n = 4). Participants were randomly allocated to either usual (0.4-4.0 mU/L) or a higher (4.1-8.0 mU/L) target serum TSH range. Information on participants' willingness to enter the trial, acceptability of study design, length of time to complete recruitment and dose titration strategy was collected.

RESULTS

Fifteen percent (57/390) of potentially eligible hypothyroid individuals consented to participate in this trial and 48 were randomised to trial medication for 24 weeks, giving a recruitment rate of 12 %. Recruitment averaged 5.5 participants per month over approximately 9 months. Eight participants withdrew (3/24 and 5/24 in the usual and higher TSH arms, respectively) with the commonest reason cited (5 patients) being tiredness. Interestingly, 3/5 participants withdrew from the site that required a visit to a Research Facility whereas only 5/43 participants withdrew from the site that offered home visits. In the higher TSH arm, of those participants who completed the study, approximately half of participants (10/19) reached target TSH.

CONCLUSIONS

It is feasible to perform a randomised controlled trial of thyroid hormones in hypothyroid patients aged 80 or older. A definitive trial would require collaboration with a large number of General Practices and the provision of home visits to achieve recruitment to time and target. Power calculations should take into account that approximately 12 % of those approached will be randomised and 1 in 6 participants are likely to withdraw from the study. Finally, several dose adjustments may be required to achieve target serum TSH levels in this age group.

TRIAL REGISTRATION

ISRCTN Number: 16043724 Registered 22 June 2012 Clinicaltrial.gov Number: NCT01647750 EudraCT Number: 2011-004425-27.

The prognostic impact of thyroid function in pulmonary hypertension

BACKGROUND

Thyroid disease is common in patients with pulmonary hypertension (PH), but its effect on long-term survival remains unknown. We examined the prognostic significance of thyroid hormone levels of free triiodothyronine (fT3) and free thyroxine and thyroid-stimulating hormone (TSH), and thyroid hormone replacement (THR) therapy in PH.

METHODS

We conducted a retrospective analysis of 1,756 patients enrolled in the Giessen PH Registry in 1999 to 2013 with baseline thyroid function data; of these, 355, 533, 498, and 370 had pulmonary arterial hypertension (PAH); including 192 with idiopathic PAH (iPAH), PH due to left heart disease, PH due to lung diseases, and chronic thromboembolic PH (CTEPH), respectively. Thyroid function parameters associated with mortality were identified using Cox regression and Kaplan-Meier analyses.

RESULTS

Transplant-free survival at 1, 3, and 5 years was 86.7%, 65.6%, and 53.0%, respectively. Absence of THR therapy was an independent predictor of death in iPAH (multivariate hazard ratio [HR], 2.50; 95% confidence interval [CI], 1.06-5.75). In patients without THR therapy, TSH levels in the lowest and highest quartiles (compared with the middle 2 quartiles) independently predicted death in iPAH (HR, 1.98; 95% CI, 1.07-3.67), whereas reduced fT3 levels were independently associated with increased death in PAH (HR, 8.30; 95% CI, 2.50-25.00) and CTEPH (HR, 1.79; 95% CI, 1.14-4.20).

CONCLUSIONS

Thyroid hormone levels and THR therapy are prognostic factors in iPAH, PAH, and CTEPH. Prospective studies are warranted to verify the prognostic significance of thyroid function and the effect of THR therapy in PH.

Clinical Relevance of Environmental Factors in the Pathogenesis of Autoimmune Thyroid Disease

Genetic factors contribute for about 70% to 80% and environmental factors for about 20% to 30% to the pathogenesis of autoimmune thyroid disease (AITD). Relatives of AITD patients carry a risk to contract AITD themselves. The 5-year risk can be quantified by the so-called Thyroid Events Amsterdam-score, based on serum thyroid-stimulating hormone, thyroid peroxidase (TPO)-antibodies and family history. Subjects at risk may ask what they can do to prevent development of AITD. This review summarizes what is known about modulation of exposure to environmental factors in terms of AITD prevention. To stop smoking decreases the risk on Graves disease but increases the risk on Hashimoto disease. Moderate alcohol intake provides some protection against both Graves and Hashimoto disease. Low selenium intake is associated with a higher prevalence of thyroid autoimmunity, but evidence that selenium supplementation may lower TPO antibodies and prevent subclinical hypothyroidism remains inconclusive. Low serum vitamin D levels are associated with a higher prevalence of TPO antibodies, but intervention studies with extra vitamin D have not been done yet. Stress may provoke Graves hyperthyroidism but not Hashimoto thyroiditis. Estrogen use have been linked to a lower prevalence of Graves disease. The postpartum period is associated with an increased risk of AITD. Taking together, preventive interventions to diminish the risk of AITD are few, not always feasible, and probably of limited efficacy.

Aberrant Levels of Hematopoietic/Neuronal Growth and Differentiation Factors in Euthyroid Women at Risk for Autoimmune Thyroid Disease

Background

Subjects at risk for major mood disorders have a higher risk to develop autoimmune thyroid disease (AITD) and vice-versa, implying a shared pathogenesis. In mood disorder patients, an abnormal profile of hematopoietic/neuronal growth factors is observed, suggesting that growth/differentiation abnormalities of these cell lineages may predispose to mood disorders. The first objective of our study was to investigate whether an aberrant profile of these hematopoietic/neuronal growth factors is also detectable in subjects at risk for AITD. A second objective was to study the inter relationship of these factors with previously determined and published growth factors/cytokines in the same subjects.

Methods

We studied 64 TPO-Ab-negative females with at least 1 first- or second-degree relative with AITD, 32 of whom did and 32 who did not seroconvert to TPO-Ab positivity in 5-year follow-up. Subjects were compared with 32 healthy controls (HCs). We measured serum levels of brain-derived neurotrophic factor (BDNF), Stem Cell Factor (SCF), Insulin-like Growth Factor-Binding Protein 2 (IGFBP-2), Epidermal Growth Factor (EGF) and IL-7 at baseline.

Results

BDNF was significantly lower (8.2 vs 18.9 ng/ml, P<0.001), while EGF (506.9 vs 307.6 pg/ml, P = 0.003) and IGFBP-2 (388.3 vs 188.5 ng/ml, P = 0.028) were significantly higher in relatives than in HCs. Relatives who seroconverted in the next 5 years had significantly higher levels of SCF than non-seroconverters (26.5 vs 16.7 pg/ml, P = 0.017). In a cluster analysis with the previously published growth factors/cytokines SCF clustered together with IL-1β, IL-6 and CCL-3, of which high levels also preceded seroconversion.

Conclusion

Relatives of AITD patients show aberrant serum levels of 4 hematopoietic/neuronal growth factors similar to the aberrancies found in mood disorder patients, suggesting that shared growth and differentiation defects in both the hematopoietic and neuronal system may underlie thyroid autoimmunity and mood disorders. A distinct pattern of four inter correlating immune factors in the relatives preceded TPO-Ab seroconversion in the next 5 years.

Quality of life in patients with primary hypothyroidism related to BMI

OBJECTIVE

Many patients treated for primary hypothyroidism have an unexplained reduced quality of life (QOL). We studied the relation between QOL and various parameters in treated hypothyroid patients.

DESIGN AND METHODS

QOL analysis was done in 90 consecutive patients (77.8% females) treated for primary hypothyroidism. QOL was measured by the questionnaires Short-Form 36, Hospital Anxiety and Depression Scale and MFI20. Post hoc analysis was performed on the relation of QOL at baseline and BMI, thyroid hormones and other serum values. QOL in patients was also compared to the general population.

RESULTS

QOL was decreased compared to the general population. We found an inverse relationship between QOL and BMI. A relationship between QOL and serum thyroid parameters or auto-antibodies could not be found. Higher sex hormone binding globulin (SHBG) levels corresponded with a better QOL, which is explained by the negative association of SHBG with body weight and BMI.

CONCLUSIONS

A decreased QOL in hypothyroid patients on thyroxine treatment is related to a higher body weight (BMI). Weight gain needs more attention in the treatment of hypothyroidism.

Relationship between thyroid-stimulating hormone levels and risk of depression among the general population with normal free T4 levels

OBJECTIVE

This study assessed the relationship between thyroid-stimulating hormone (TSH) level and risk of depressive symptom in a population with no clinical or laboratory evidence of thyroid dysfunction.

METHODS

This retrospective cohort study included 13,017 subjects (7913 males and 5104 females), 17-84 years of age, who underwent health examinations at the hospital. Subjects had a Beck Depression Inventory (BDI) total score of ≤9 and fell within the normal range of free T4 levels at baseline. The association between gender-specific serum TSH tertile at baseline and the development of clinically significant depressive symptom (i.e., ≥19 BDI total score) on the follow-up visit was evaluated using the Cox proportional hazards model, with adjustment for demographic and life style factors.

RESULTS

The risk of depressive symptom was increased among subjects with the highest tertile TSH level (adjusted hazard ratio [HR], 2.236; 95% confidence interval [CI], 1.443-3.466; p<0.001) as compared with subjects with the lowest tertile in females, but not in males. Even among patients with normal TSH levels, females in the lowest-normal TSH tertile had a higher risk of depressive symptoms (adjusted HR, 2.279; 95% CI, 1.456-3.567; p<0.001) than did those in the highest tertile. The TSH level as a continuous variable significantly predicted the depressive symptoms in females (adjusted HR, 1.402; 95% CI, 1.002-1.812; p=0.027).

CONCLUSIONS

Our finding suggests that suboptimal thyroid function increases vulnerability to the occurrence of depressive symptom and represents a modifiable risk factor for depression in females.

Prognostic Role of Hypothyroidism in Heart Failure: A Meta-Analysis

Hypothyroidism is a risk factor of heart failure (HF) in the general population. However, the relationship between hypothyroidism and clinical outcomes in patients with established HF is still inconclusive.We conducted a systematic review and meta-analysis to clarify the association of hypothyroidism and all-cause mortality as well as cardiac death and/or hospitalization in patients with HF. We searched MEDLINE via PubMed, EMBASE, and Scopus databases for studies of hypothyroidism and clinical outcomes in patients with HF published up to the end of January 2015. Random-effects models were used to estimate summary relative risk (RR) statistics. We included 13 articles that reported RR estimates and 95% confidence intervals (95% CIs) for hypothyroidism with outcomes in patients with HF. For the association of hypothyroidism with all-cause mortality and with cardiac death and/or hospitalization, the pooled RR was 1.44 (95% CI: 1.29-1.61) and 1.37 (95% CI: 1.22-1.55), respectively. However, the association disappeared on adjustment for B-type natriuretic protein level (RR 1.17, 95% CI: 0.90-1.52) and in studies of patients with mean age <65 years (RR 1.23, 95% CI: 0.88-1.76).We found hypothyroidism associated with increased all-cause mortality as well as cardiac death and/or hospitalization in patients with HF. Further diagnostic and therapeutic procedures for hypothyroidism may be needed for patients with HF.