Increased prevalence of antibodies to central nervous system tissue and gangliosides in Hashimoto's thyroiditis compared to other thyroid illnesses

Brain alteration of autoimmune thyroid disease: Neuropsychiatric impact, neuroimaging insights, and neurobiological implications

Autoimmune thyroid disease (AITD) is the most common organ-specific autoimmune disease, characterized by thyroid function disorder and autoimmune imbalance. Previous studies have demonstrated the decreased quality of life and neuropsychiatric manifestations in AITD patients, including anxiety, depression, cognitive impairment and affective disorder. These problems also plague the euthyroid AITD patients. Advanced neuroimaging techniques were well carried out and employed as an explanatory instrument for the above intriguing phenomenon. In recent years, an increasing number of neuroimaging studies have reported that these neuropsychiatric manifestations are accompanied by significant structural and functional brain alterations in AITD patients, mainly involved in neurocognitive and emotional regions, despite the underlying neurobiological mechanism is still unclear. The existing studies suggest that the potential pathogenesis of the neuropsychiatric manifestations and brain alterations does not depend on a single factor, but may result from a combination of thyroid function dysfunction, metabolic disorders, dysregulated autoimmune and trans-synaptic degeneration.

Focal central neurological disorder in patients with autoimmune thyroid disease without encephalopathy

The report underscores the necessity for a comprehensive evaluation in patients with suggestive laboratory findings or AITD history. Prompt diagnosis and appropriate management are imperative in averting long-term complications.

Depression severity partially mediates the association between thyroid function and psychotic symptoms in first-episode, drug-naive major depressive disorder patients with comorbid anxiety at different ages of onset

BACKGROUND

Anxiety and psychotic symptoms are common in patients with major depressive disorder (MDD), with a strong association with thyroid function. Age of onset contributes to the heterogeneity of MDD patients. This study aimed to assess the prevalence of psychotic symptoms in MDD patients with comorbid anxiety and to explore the relationship between thyroid function and psychotic symptoms by ages of onset.

METHODS

A total of 894 first-episode, drug-naïve Chinese Han MDD patients with comorbid anxiety were recruited. Thyroid function and psychometric measures including Hamilton Anxiety Scale, Hamilton Depression Scale, and Positive and Negative Syndrome Scale were evaluated. Patients were divided into early adulthood onset (EAO, < 45 years old) and mid-adulthood onset (MAO, ≥ 45 years old) groups.

RESULTS

The MAO subgroup had a higher prevalence of psychotic symptoms compared to EAO subgroup. TSH and TPOAb levels were positively correlated with psychotic symptoms severity, with a more pronounced effect in MAO subgroup. Furthermore, MDD severity partially mediated the effects of TPOAb and TSH levels on psychotic symptoms in both subgroups.

LIMITATIONS

A causal relationship could not be demonstrated with this cross-sectional study, and the results should be limited to first-episode, drug-naïve MDD patients without considering more potential confounders. Moreover, the male-to-female ratio imbalance is present.

CONCLUSIONS

Our results indicated that age of onset moderated the association between thyroid function and psychotic symptom, and depression severity partially mediated the effects of thyroid function on psychotic symptoms, suggesting thyroid function may serve as a biomarker of psychotic symptoms in MDD patients with anxiety.

Subclinical Hypothyroidism and Incident Depression in Adolescents and Young Adults: Results from a Nationwide Representative Prospective Study

Background: Although the relationship between subclinical hypothyroidism and major depressive disorder (MDD) has been studied in adults in cross-sectional and prospective population-based studies, this has not yet been done in adolescents. However, since thyroid function and MDD risk are subjected to maturational processes and ramifications of illness duration over the life span, these findings may not readily transfer to adolescents. Methods: The relationship between subclinical hypothyroidism and MDD was studied in a representative subsample of the nationwide KIGGS ("The German Health Interview and Examination Survey for Children and Adolescents") survey. A total of 4118 adolescents were examined over a median period of 6 years, and data were analyzed by a logistic regression approach accounting for important covariates related to thyroid function and/or MDD risk. The same approach was chosen to investigate the relationship between quartiles of thyrotropin (TSH) and free thyroxine (fT4) levels and incident MDD in euthyroid participants to broaden the focus on the relationship between thyroid hormone levels and MDD in a dose-response manner. Results: During the observation period, 121 cases of MDD were reported. There was no association between subclinical hypothyroidism and MDD when comparing 111 adolescents with subclinical hypothyroidism with 4007 euthyroid adolescents, representative of ∼106,000 and 3,610,000 adolescents from the general pediatric population, respectively. This also applied when studying the relationship between quartiles of TSH and fT4 levels and MDD in euthyroid participants. All results were confirmed by sensitivity analyses accounting for thyroid autoimmunity. Conclusions: Consistent with findings in adults, there is no association between subclinical hypothyroidism or quartiles of TSH and fT4 levels in the normal range and MDD in adolescents, despite potential age-related differences regarding thyroid function and MDD risk.

Association between anti-thyroid antibodies and quality of life in patients with Hashimoto thyroiditis: a systematic review and meta-analysis

OBJECTIVE

The aim of this review was to evaluate the association between anti-thyroid antibodies and quality of life in people with euthyroid Hashimoto thyroiditis.

INTRODUCTION

Patients with Hashimoto thyroiditis report symptom distress more often than those with non-autoimmune thyroid disorders. Therefore, anti-thyroid antibodies may be related to decreased quality of life in persons with Hashimoto thyroiditis. The etiology of lingering symptoms, even in euthyroidism, remains unknown. The relationship between anti-thyroid antibodies and quality of life for people with Hashimoto thyroiditis has not been evaluated in a systematic review.

INCLUSION CRITERIA

The participants were males and females at least 12 years of age, in any country, with Hashimoto thyroiditis. Participants not in a euthyroid state were excluded from this review. In this review, the exposure was the presence of anti-thyroid antibodies and the primary outcome was quality of life as measured by a validated scale.

METHODS

A three-step search strategy was implemented with an initial search of PubMed and CINAHL. A comprehensive database search using all identified keywords and index terms was undertaken in March 2019 for relevant published literature, gray literature, and clinical trial registries. The final updates to the search strategies were conducted in December 2019. The search was limited to studies published in English after 1956. Two independent reviewers completed screening for inclusion and utilized the recommended JBI approach to critical appraisal, study selection, data extraction, and data synthesis. The findings are presented in a meta-analysis and in a narrative synthesis, which includes tables and figures.

RESULTS

All 13 studies had high methodological quality. Four studies found a significant correlation (P < 0.05) between the presence of anti-thyroid antibodies and quality of life. A fifth study found a significant correlation (P < 0.001) between higher antibody levels and quality of life. A meta-analysis was conducted using two cross-sectional studies, which revealed that the summative small effect size was statistically significant and suggested a lower quality of life in antibody-positive patients. Due to the heterogeneity of the studies, a narrative synthesis was conducted for the three secondary outcomes: symptom distress, executive function, and mental health. Three studies found a statistically significant (P < 0.05) correlation between symptom distress and antibodies, two studies found a statistically significant (P < 0.05) association between executive function and antibodies, and all but one study found a statistically significant (P < 0.05) relationship between mental health and antibodies.

CONCLUSIONS

The findings in this review did not reveal a definitive relationship between antibodies and quality of life. However, our meta-analysis suggested a link between anti-thyroid antibodies and decreased quality of life in euthyroid children and adults. Though not conclusive, poor mental health and symptom distress may be associated with anti-thyroid antibodies. Therefore, it may be beneficial to periodically evaluate the quality of life and mental health in euthyroid patients with positive antibodies. It is unlikely that antibodies and executive functions are related. The studies and our review's limitations require replication of findings to confirm a connection between antibodies, quality of life, and the secondary outcomes. Future research should continue to evaluate the relationship between anti-thyroid antibodies and the quality of life in individuals with euthyroid Hashimoto thyroiditis.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42018084663.

The relation between thyroid dysregulation and impaired cognition/behaviour: An integrative review

Despite decades of research on the relation between thyroid diseases and cognition, the nature of this relationship remains elusive. An increasing prevalence of cognitive impairment and thyroid dysfunction has been consistently observed with ageing. Also, there appears to be an association between thyroid disorders and cognitive decline. Given the increasing global burden of dementia, elucidating the relationship between thyroid disorders as a potentially modifiable risk factor of cognitive impairment was the main goal of this review. We summarise the current literature examining the relationship between thyroid hormonal dysregulation and cognition or behaviour. We present the available imaging and pathological findings related to structural and functional brain changes related to thyroid hormonal dysregulation. We also propose potential mechanisms of interaction between thyroid hormones, autoantibodies and cognition/behaviour. Effects of gender, ethnicity and environmental factors are also briefly discussed. This review highlights the need for long-term prospective studies to capture the course of brain functional changes associated with the incidence and progression of thyroid dysregulations along with the confounding effects of non-modifiable risk factors such as gender and ethnicity. Moreover, double-blind controlled clinical trials are necessary to devise appropriate treatment plans to prevent cognitive consequences of over or undertreatment of thyroid disorders.

Differences in Thyroid Function and Autoantibodies in the Development of Guillain-Barré Syndrome vs. Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Background: Both Guillain–Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are neurodegenerative and inflammatory demyelination disorders. Sporadic reports showed that the increased levels of thyroid function and autoantibodies are associated with GBS, CIDP, or both, but no systematic study has been reported. We assessed the differences of thyroid function and autoantibodies between GBS and CIDP in a Chinese cohort.

Methods: A total of 256 patients were enrolled in this study. 175 clinically confirmed GBS and CIDP patients were selected. Meanwhile, 81 patients hospitalized for diseases other than GBS or CIDP with mild symptoms were enrolled as a control group. Relevant clinical data, including thyroid function, and autoantibody examinations, were collected for statistical analysis.

Results: In the comparison of thyroid function and autoantibody parameters, the levels of total thyroxine (TT4), thyroid peroxidase antibody (TPO-Ab), and thyroglobulin antibody (TG-Ab) in the GBS group were all higher than those in the CIDP and Control groups (P < 0.01). The thyroid antibody positive rates in the GBS and CIDP groups were 70.10 and 14.10%, respectively (P < 0.01). In the receiver operating characteristic (ROC) curve analysis, TT4, TPO-Ab, and TG-Ab were higher in the GBS group and lower in the CIDP group (P < 0.01). To achieve a high specificity of 97–99%, the diagnostic cutoff value of TPO-Ab was higher than 133 IU/mL (Sensitivity: 11.34%) or lower than 0.01 IU/mL (Sensitivity: 9.09%), while the diagnostic cutoff value of TG-Ab was higher than 261.1 IU/mL (Sensitivity: 2.06%) or lower than 0.46 IU/mL (Sensitivity: 11.69%). Multivariate logistic regression analysis showed that the differences in TPO-Ab were statistically significant between GBS patients with TPO-Ab was higher than 133 IU/mL and CIDP patients (P < 0.01); the differences in TG-Ab were statistically significant between GBS patients with TG-Ab was higher than 261.1 IU/mL and CIDP patients (P < 0.05).

Conclusion: The elevation of thyroid autoantibodies was associated with GBS. TPO-Ab higher than 133 IU/mL or lower than 0.01 IU/mL and TG-Ab higher than 261.1 IU/mL or lower than 0.46 IU/mL had high specificity for differentiating between GBS and CIDP; therefore, TPO-Ab and TG-Ab can be used as biomarkers for the differential diagnosis of GBS and CIDP.

Individualized Therapy for Hypothyroidism: Is T4 Enough for Everyone?

CONTEXT

It is well recognized that some hypothyroid patients on levothyroxine (LT4) remain symptomatic, but why patients are susceptible to this condition, why symptoms persist, and what is the role of combination therapy with LT4 and liothyronine (LT3), are questions that remain unclear. Here we explore evidence of abnormal thyroid hormone (TH) metabolism in LT4-treated patients, and offer a rationale for why some patients perceive LT4 therapy as a failure.

EVIDENCE ACQUISITION

This review is based on a collection of primary and review literature gathered from a PubMed search of "hypothyroidism," "levothyroxine," "liothyronine," and "desiccated thyroid extract," among other keywords. PubMed searches were supplemented by Google Scholar and the authors' prior knowledge of the subject.

EVIDENCE SYNTHESIS

In most LT4-treated patients, normalization of serum thyrotropin levels results in decreased serum T3/T4 ratio, with relatively lower serum T3 levels; in at least 15% of the cases, serum T3 levels are below normal. These changes can lead to a reduction in TH action, which would explain the slower rate of metabolism and elevated serum cholesterol levels. A small percentage of patients might also experience persistent symptoms of hypothyroidism, with impaired cognition and tiredness. We propose that such patients carry a key clinical factor, for example, specific genetic and/or immunologic makeup, that is well compensated while the thyroid function is normal but might become apparent when compounded with relatively lower serum T3 levels.

CONCLUSIONS

After excluding other explanations, physicians should openly discuss and consider therapy with LT4 and LT3 with those hypothyroid patients who have persistent symptoms or metabolic abnormalities despite normalization of serum thyrotropin level. New clinical trials focused on symptomatic patients, genetic makeup, and comorbidities, with the statistical power to identify differences between monotherapy and combination therapy, are needed.

Thyroid gland and brain: Enigma of Hashimoto's encephalopathy

The versatile clinical manifestations of the Hashimoto's chronic autoimmune thyroiditis often include psycho-neurological disorders. Although hypothyroidism disturbs significantly the ontogenesis and functions of central nervous system, causing in severe cases of myxedema profound impairment of cognitive abilities and even psychosis, the behavioral, motor and other psychoneurological disorders accompany euthyroid and slightly hypothyroid cases and periods of Hashimoto's disease as well, thus constituting the picture of so called "Hashimoto's encephalopathy". The entity, although discussed and explored for more than 50 years since its initial descriptions, remains an enigma of thyroidology and psychiatry, because its etiology and pathogenesis are obscure. The paper describes the development of current views on the role of thyroid in ontogeny and functions of brain, as well as classical and newest ideas on the etiology and pathogenesis of Hashimot's encephalopathy. The synopsis of the world case reports and research literature on this disorder is added with authors' own results obtained by study of 17 cases of Hashimoto's thyroiditis with schizophrenia-like clinical manifestations. The relation of the disease to adjuvant-like etiological factors is discussed. Three major mechanistic concepts of Hashimoto's encephalopathy are detailed, namely cerebral vasculitis theory, hormone dysregulation theory and concept, explaining the disease via direct action of the autoantibodies against various thyroid (thyroperoxidase, thyroglobulin, and TSH-receptor) and several extrathyroid antigens (alpha-enolase and other enzymes, gangliosides and MOG-protein, onconeuronal antigens) - all of them expressed in the brain. The article demonstrates that all above mentioned concepts intermingle and prone to unification, suggesting the unified scheme of pathogenesis for the Hashimoto's encephalopathy. The clinical manifestations, criteria, forms, course, treatment and prognosis of Hashimoto's encephalopathy and its comorbidity to other diseases - are also discussed in brief. The relation between Hashimoto's encephalopathy and non-vasculitis autoimmune encephalomyelitides of paraneoplastic and non-paraneoplastic origin is emphasized [1 figure, bibliography - 200 references].

Behavior in dogs with spontaneous hypothyroidism during treatment with levothyroxine

Background

Thyroid hormone supplementation anecdotally has been described as a valid treatment option for dogs with aggression‐related problems. However, prospective, controlled, and blinded trials evaluating behavior and neurohormonal status in hypothyroid dogs during treatment with levothyroxine are lacking.

Objective

Levothyroxine supplementation will have a significant influence on the behavior and neurohormonal status of dogs with spontaneous hypothyroidism.

Animals

Twenty client‐owned dogs diagnosed with spontaneous hypothyroidism.

Methods

This prospective study was to evaluate the behavior of dogs, which was screened at initial presentation, and after 6 weeks, and 6 months of treatment with levothyroxine (starting dosage 10 μg/kg PO q12h) using the standardized Canine Behavioral Assessment and Research Questionnaire (C‐BARQ). At each time period, circulating serotonin and prolactin (PRL) concentrations were evaluated using a commercially validated ELISA kit and heterologous radioimmunoassay, respectively.

Results

After 6 weeks of thyroid hormone supplementation, C‐BARQ scores demonstrated a significant increase in activity of hypothyroid dogs (P < .01). No significant change in any of the behavioral signs was observed after 6 months of treatment. No significant difference in circulating concentrations of serotonin (P > .99 and P = .46) and PRL (P = .99 and P = .37) were noted between the 6‐week and 6‐month periods compared with baseline.

Conclusions and Clinical Importance

The results of this study indicate increased activity of hypothyroid dogs after 6 weeks of thyroid hormone supplementation. None of the hypothyroid dogs in this cohort showed a significant change in any of the evaluated behavioral signs and neurohormonal status after 6 months of thyroid hormone supplementation.

Association between autoimmune thyroiditis and depressive disorder in psychiatric outpatients

Thyroid diseases are often associated with psychiatric disorders. The prevalence of autoimmune thyroiditis in the general population is estimated to be at about 5-14 %. A clinical study was conducted to evaluate the association between autoimmune thyroiditis and depression in psychiatric outpatients. Fifty-two patients with depression and nineteen patients with schizophrenia (serving as control group), attending a psychiatric outpatient unit, were included. In addition to the measurement of thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, antithyroid peroxidase (anti-TPO) antibodies, and anti-thyroglobulin antibodies, ultrasound examination of the thyroid gland was performed. The proportion of pathologically increased anti-TPO levels in patients with depression was high. Furthermore, the distribution of pathologically increased anti-TPO levels was significantly (χ (2) = 5.5; p = 0.019) different between patients with depression (32.7 %) and patients with schizophrenia (5.3 %). In a gender- and age-adjusted logistic regression, the odds ratio of uni- or bipolar patients with depression for an autoimmune thyroiditis was ten times higher (95 % CI = 1.2-85.3) when compared with schizophrenia patients. TSH basal level did not differ between patients with depression and patients with schizophrenia. Our study demonstrates a strong association between anti-TPO levels, which are considered to be of diagnostic value for autoimmune thyroiditis (in combination with a hypoechoic thyroid in ultrasonography) with uni- or bipolar depression. It should be noted that the routinely measured TSH level is not sufficient in itself to diagnose this relevant autoimmune comorbidity.

Cognitive and affective dysfunctions in autoimmune thyroiditis

Hashimoto's thyroiditis (HT) is the most frequent cause of hypothyroidism in areas with sufficient iodine intake. While the impact of thyroid function on mood and cognition is well known, only in the recent years, an increasing number of studies report on the association of HT with cognitive and affective disturbances also in the euthyroid state. Recent imaging studies have shown that these impairments are accompanied by altered brain perfusion, in particular, in the frontal lobe and a reduced gray matter density in the left inferior gyrus frontalis. Brain function abnormalities in euthyroid patients with HT may be subtle and only detected by specific testing or even severe as it is the case in the rare neuropsychiatric disorder Hashimoto's encephalopathy (HE). The good response to glucocorticoids in patients with HE indicates an autoimmune origin. In line with this, the cognitive deficits and the high psycho-social burden in euthyroid HT patients without apparent signs of encephalopathy appear to be associated with anti-thyroid peroxidase auto-antibody (TPO Abs) levels. Though in vitro studies showing binding of TPO Abs to human cerebellar astrocytes point to a potential direct role of TPO Abs in the pathogenesis of brain abnormalities in HT patients, TPO Abs may function only as a marker of an autoimmune disorder of the central nervous system. In line with this, anti-central nervous system auto-antibodies (CNS Abs) which are markedly increased in patients with HT disturb myelinogenesis in vitro and, therefore, may impair myelin sheath integrity. In addition, in HT patients, production of monocyte- and T-lymphocyte-derived cytokines is also markedly increased which may negatively affect multiple neurotransmitters and, consequently, diverse brain neurocircuits.

A novel luminescence-based method for the detection of functionally active antibodies to muscarinic acetylcholine receptors of the M3 type (mAchR3) in patients' sera

In different bioassays, functional antibodies reacting with the human muscarinic acetylcholine receptor M3(mAchR3) have been detected in sera from patients with Sjögren's syndrome (SS), and there is strong evidence that those antibodies may have pathogenetic relevance. However, depending on the method of detection, their prevalence varied. Furthermore, those bioassays are difficult to standardize. We report on the development and optimization of a novel test system based on a luminometric method to determine downstream signalling of mAchR3 which produces specific and reproducible results. Chinese hamster ovarian (CHO) cells were transfected with plasmids encoding mAchR3 and a green fluorescence protein (GFP)/aequorin fusion protein. Incubation of cells with carbachol resulted in an increase in intracellular [Ca(2+)], which was detected by measuring light emission with a luminometer, and the effect of incubation with patients' immunoglobulins (Ig) was evaluated. Optimal cell density, Ig preparation and time of incubation with patients' sera were determined. Sera from patients with primary Sjögren's syndrome (pSS; n = 40), systemic sclerosis (SSc; n = 47), myasthenia gravis (MG; n = 133) and 50 blood donors were analysed. Optimal assay conditions were obtained with a cell density of 100 000 cells/ml, isolation of Ig by ammonium sulphate precipitation and short-term incubation. Based on this highly reliable assay, 50% of the pSS patients had antibodies which inhibited carbachol-induced activation of mAchR3; none of the SSc patients, 6% of the patients with MG and 12% of the blood donors had antibodies which reacted with the mAchR3. This method facilitates the determination of functional anti-mAchR3 antibodies in patients' sera, confirmed their high prevalence in pSS patients and may, therefore, help to analyse their pathogenetic and clinical relevance in more detail.

Antibodies in autoimmune thyroiditis affect glucose metabolism of anterior cingulate

BACKGROUND

Hypothyroidism induced by an autoimmune process is associated with neuropsychiatric symptoms and metabolic abnormalities in the brain. The aim of this study was to examine the relationship between autoimmune thyroiditis and regional brain function in hypothyroid patients.

METHODS

Cerebral glucose metabolism, as an index of brain function, was assessed in regional whole-brain analyses using positron emission tomography (PET) and [18F]fluorodeoxyglucose in thirteen hypothyroid patients with autoimmune thyroiditis suffering from neuropsychiatric symptoms. The primary biological measures were radioactivity in pre-selected brain regions, relative to whole-brain radioactivity, as a surrogate index of glucose metabolism, and serum levels of thyroglobulin (TG) and thyroid peroxidase (TPO) antibodies as endocrine markers of autoimmune thyroiditis.

RESULTS

Serum levels of anti-TG antibodies in hypothyroid patients were significantly correlated with glucose metabolism in the perigenual anterior cingulate cortex, a brain region previously shown to regulate affect and emotional homeostasis.

CONCLUSION

Thyroid autoimmune processes may play an important role in the still poorly defined pathogenic correlates of disturbed function in brain regions critically involved in emotional processing in hypothyroid conditions.

Low performance in attention testing is associated with reduced grey matter density of the left inferior frontal gyrus in euthyroid patients with Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) can casually co-occur with an encephalopathy associated with autoimmune thyroid disease. Recently we found an increased occurrence of weaknesses in sustained attention and response inhibition in a subgroup of euthyroid patients with HT as obtained by the d2 attention test. Previous studies in healthy subjects and patients with brain lesions demonstrated a pivotal role for the left inferior frontal gyrus (LIFG) in these skills. Therefore, we studied the association between the performance in the d2 test and grey matter (GM) density of the LIFG in 13 euthyroid patients with HT compared to a control group of 12 euthyroid patients with other thyroid diseases. A significant correlation between GM density and d2 test total score was detected for the opercular part of the LIFG in patients with HT (p<0.001), but not in the control group (p=0.94). Regression in patients with HT was significantly stronger than in the control group (p=0.02). Moreover, GM density was significantly reduced when comparing HT patients with control patients that scored in the lower third during d2 attention testing (p<0.05). It can be concluded that in HT performance in the d2 test correlated with GM density of the LIFG. Particularly low achievement was associated with reduced GM density of this brain region suggesting an influence of autoimmune processes on the frontal cortex in this disease. This could be due to not yet known antibodies affecting brain morphology or an influence of thyroid antibodies themselves.

Thyroid peroxidase antibody positivity is associated with symptomatic distress in patients with Hashimoto's thyroiditis

Previous studies suggest impairments of physical, mental, and psychic well-being in patients with Hashimoto's thyroiditis (HT), but these impairments have been shown to be independent of thyroid dysfunction. In 64 euthyroid patients with HT, symptomatic distress was assessed with the Symptom Checklist-90-Revised (SCL-90-R), a 90-item multidimensional self-report symptom inventory using a 5-point rating scale. In a subgroup of patients, endocrine testing 3 years prior to the current investigation was available. Anti-thyroid peroxidase antibodies (TPO-Abs) were associated with the three SCL-90-R global indices Global Severity Index (GSI), Positive Symptom Distress Index (PSDI), and Positive Symptom Total (PST) as well as with somatization and obsessive-compulsive symptoms after adjustment for age, gender, and thyroid function as assessed by TSH levels (all p<0.05). HT patients positive for TPO-Abs showed poorer results in the three SCL-90-R global indices as well as in the three domains: somatization, obsessive-compulsive symptoms, and depression (all p≤0.02), though the aforementioned associations did not withstand sequential Bonferroni correction for multiple testing. In contrast, TPO-Abs positivity, defined as TPO-Abs >100 IU/l, significantly predicted poorer psychosocial well-being in all of the three SCL-90-R global indices after three years, even after correction (all p≤0.02). In conclusion, high TPO-Abs are associated with poor physical and psychological well-being and appear to predict future health perception in HT patients.

Early pospartum alexithymia and risk for depression: relationship with serum thyrotropin, free thyroid hormones and thyroid autoantibodies

Most psychometric evaluations in the postpartum (PP) target depression (PPD) and show an association with thyroid autoantibodies (TAb), not with thyroid function. Three studies evaluated PP alexithymia, but none its relationship with thyroid indices. We tested 74 women aged 31.8±4.64 years, on day 3 PP, by the Edinburgh Postnatal Depression Scale (EPDS), the Montgomery and Asberg Depression Rating Scale (MADRS), and the Toronto Alexithymia Scale (TAS). Concurrently, we measured serum thyrotropin (TSH), free T3 (FT3), free T4 (FT4), thyroperoxidase and thyroglobulin antibodies (TPOAb, TgAb). Using cut-off scores of ≥12 (EPDS), ≥15 (MADRS) and ≥61 (TAS), rates of women with abnormal EPDS and MADRS scores were similar (31%, 30% and 28.4%, respectively). TAS scores were higher and proportions of alexithymics were greater in the abnormal EPDS group or in the abnormal MADRS group than in the normal EPDS or MADRS group. EPDS correlated significantly with TAS. Compared to nonalexithymics, alexythimics had lower FT4, higher FT3, lower FT4:FT3 ratio, and insignificantly higher TPOAb or TgAb levels. Only TPOAb and TgAb were significantly higher in women at risk for PPD compared to women not at risk for PPD, but solely at EPDS cut-off values of ≥13 or ≥14. TAS correlated directly with TPOAb and FT3, and inversely with FT4:FT3 ratio, while EPDS correlated only with TPOAb. Comparing women at risk for depression but nonalexithymics or women alexithymics but not at risk for depression vs. women normal on all scales, the former had lower FT3 and higher FT4:FT3 ratio while the latter had lower both FT4 and FT4:FT3 ratio. We conclude that PPD risk and alexithymia (i) are partly comorbid and directly associated with thyroid autoimmunity; (ii) their association with serum free thyroid hormones and with FT4:FT3 ratio goes in opposite directions.

Hashimoto's thyroiditis in patients with normal thyroid-stimulating hormone levels

Hashimoto's thyroiditis (HT) is one of the most common autoimmune endocrine disorders and often leads to hypothyroidism. It has been shown to substantially affect a patient's quality of life. Associated conditions and diseases were thought to be attributable to hypothyroidism. Yet, many patients still suffer from various symptoms even though all thyroid parameters are within the normal range. Independently of thyroid gland function, HT is associated with a wide range of organ-specific and non-organ-specific autoimmune disorders, as well as other diseases, including neuropsychological/psychiatric deficits, decreased left ventricular performance, disorders of the gut, fibromyalgia and reproductive health issues, among others. The underlying pathomechanisms remain unclear. Future treatment options might include thyroidectomy, selenium administration, prophylactic levothyroxine supplementation and dehydroepiandrosterone. However, further research is warranted to clarify the main pathophysiologic implications of thyroid autoimmunity and also to establish treatment options for euthyroid patients who suffer from HT-related symptoms and diseases.

Mild thyroid hormone excess is associated with a decreased physical function in elderly men

INTRODUCTION

In the adult, subclinical hyperthyroidism (Shyper) may alter skeletal muscle mass and strength. However, whether these effects are present in elderly subjects is not known. We explored the relationship between mild hyperthyroidism and physical function in a population-based sample of older persons.

METHODS

In a cross-sectional analysis, calf muscle cross-sectional area (CMA), handgrip strength, nerve conduction velocity (NCV), and Short Physical Performance Battery (SPPB) scores were compared between 364 euthyroid (Eut) and 28 Shyper men as well as between 502 Eut and 39 Shyper women. In a longitudinal analysis, we evaluated the relationship between baseline plasma TSH, FT3 and FT4 and the 3-year change in SPPB score in 304 men and 409 women who were euthyroid at enrolment.

RESULTS

At the cross-sectional analysis, Shyper men, but not women, had a significantly (p = 0.02) lower SPPB score than Eut controls, although with comparable CMA, grip strength and NCV, and were more likely to have poor physical performance (odds ratio = 2.97, p < 0.05). Longitudinal analysis showed that in Eut men higher baseline FT4 was significantly (p = 0.02) predictive of a lower SPPB score at the 3-year follow-up.

CONCLUSION

Even a modest thyroid hormone excess is associated with a reduced physical function in elderly men.

Thyroid disease and mental disorders: cause and effect or only comorbidity?

PURPOSE OF REVIEW

To discuss the effects of thyroid dysfunction and thyroid autoimmunity on mental symptoms and disorders in patients with thyroid disease with reference to recent epidemiological, clinical, and genetic findings.

RECENT FINDINGS

During brain development, iodine deficiency, maternal thyroid dysfunction, and neonatal thyroid malformations together with genetic factors contribute to neurological deficit. Most adults with thyroid dysfunction will develop mental symptoms. In hyperthyroidism, adrenergic hyperactivity is a major cause of psychiatric symptoms, and beta-adrenergic antagonists are effective treatment. Most patients with severe hypothyroidism will also demonstrate mental symptoms; however, causality is not so evident as in hyperthyroidism. Polymorphism in deiodinase genes and in transporter genes appears to make an important contribution to the presentation of mental symptoms as well as to the outcome of treatment of hypothyroidism. A thyroid autoimmunity process may by itself contribute to mental symptoms in vulnerable patients. Data from epidemiological studies provide conflicting evidence as to associations between thyroid disorders and mental symptoms.

SUMMARY

In the adult brain, compared with the developing brain, brain-thyroid relationships are less apparent but still important. Adrenergic hyperactivity is a major cause of psychiatric symptoms in hyperthyroidism. Genetic factors contribute to the development and treatment outcome of mental disorder in hypothyroidism.