Association between subclinical thyroid dysfunction and depressive symptoms in the Korean adult population: The 2014 Korea National Health and Nutrition Examination Survey

The effect of neuroendocrine abnormalities on the risk of psychiatric readmission after hospitalization for bipolar disorder: A retrospective study

BACKGROUND

The correlation between the endocrine system and bipolar disorder(BD) has been well recognized, yet the influence of neuroendocrine hormones on readmission risk post-hospitalization for BD remains largely unexplored. This retrospective cohort study was to scrutinize the impact of neuroendocrine functionality on the readmission of patients with BD post-hospitalization for mental disorders.

METHODS

The dataset was derived from the electronic medical records of the First Affiliated Hospital of Jinan University in Guangzhou, China. Both univariate and multivariate logistic regression analysis were conducted on all patients hospitalized for BD, and from 1 January 2017 to October 2022.

RESULTS

Of the 1110 eligible patients, 83 and 141 patients experienced psychiatric readmissions within 90 and 180 days post-discharge, respectively. Multivariate analysis revealed that high serum TSH levels (aOR = 1.079; 95%CI = 1.003-1.160) and thyroid disease comorbidities (aOR = 2.899; 95%CI = 1.303-6.452) were independently correlated with the risk of 90-day readmission; while increased serum TSH levels (aOR = 1.179; 95%CI = 1.081-1.287) represented a risk factor for 180-day readmission. These results indicate that high serum TSH levels and thyroid disease comorbidities may contribute to an elevated readmission risk in patients with BD following hospitalization.

CONCLUSION

Routinely evaluating and intervening in thyroid function is crucial in the treatment of BD, as it may aid in preventing re-hospitalization.

Prevalence of self-reported thyroid disease among adults with depression

BACKGROUND

Thyroid disorders are a common comorbidity in patients with depression, yet there is limited information available about the clinical epidemiology of thyroid diseases in this specific population. This study aims to describe the prevalence of thyroid disease among US adults with depression from 2007 to 2018.

METHODS

This cross-sectional study used nationally representative data collected through the National Health and Nutrition Examination Survey (NHANES) between January 1, 2007, to December 31, 2018. Age-standardized prevalence of thyroid disease among depressed patients was calculated within 4-year survey periods (2007-2010, 2011-2014, and 2015-2018), and adjusted to the 2000 U.S. standard population.

RESULTS

In our weighed sample, 6.1% of depressed individuals and 4.3% of non-depressed individuals reported thyroid disease between 2007 and 2018 (P < 0.0001). The age-standardized prevalence of thyroid disease in patients with depression increased over time, from 5.4% (95%CI, 4.6%-6.2%) in 2007-2010 to 6.8% (95%CI, 5.8%-8.0%) in 2015-2018 (P for trend = 0.0270). Furthermore, thyroid disease prevalence was highest in non-Hispanic white individuals, increased with age, and tended to be higher in women. Mean depression scores in patients with thyroid disease (9.1; 95%CI, 8.7-9.5) did not significantly different from those without thyroid disease (9.1; 95%CI, 9.0-9.3) (P = 0.96).

CONCLUSION

The age-standardized prevalence of thyroid disease among US adults with depression exhibited a consistent increase from 2007 to 2018, with the highest rate occurring in older, non-Hispanic white individuals, and women.

Quality of life, social support, and adherence in female patients with thyroid disorders

BACKGROUND

According to the 2010 European Health Interview Survey, 51% of women in Hungary have a chronic disease, and is among the poorest quartile in the EU countries. Thyroid diseases affected more than 650,000 women in 2021 based on a recent report by the Hungarian Central Statistical Office. Despite the high prevalence rates, quality of life in these patients is scarcely researched in Hungary. To fill this gap, this study aims to explore the associations of the quality of life of thyroid patients in Hungary with social support and adherence.

METHODS

A cross-sectional study was conducted via an online questionnaire. Data from 885 female Hungarian thyroid patients with pharmacological treatment (M = 35.6 years, SD = 10.7, age range: 18-73 years) were analyzed. Participants were divided into two patient groups based on the type of thyroid disorder: hypothyroidism (n = 824; 93.1%) and hyperthyroidism (n = 61; 6.9%). Group comparisons, correlations, and a mediation model were performed to explore differences between thyroid patients.

RESULTS

No differences were found between patients with different types of thyroid disorders in quality of life, adherence, and social support. Consistent, weak associations were found between quality of life and social support in both patient groups. Higher perceived social support partially explained the relationship between adherence and life quality in thyroid patients.  CONCLUSIONS: No substantial differences were found between patients with different types of thyroid disease in mental well-being indicators. These patients are psychologically more vulnerable and need a socially supportive environment to recover, because higher adherence is associated with a better quality of life, and social support can facilitate this process.

Insights Into the Association Between Myasthenia Gravis and Depression: A Clinical Case Study

Myasthenia gravis (MG) is a serious and debilitating autoimmune disease characterized by muscle weakness, shortness of breath, and issues affecting the eyes, limbs, throat, and speech. Given the intense physical toll of the disease, it is unsurprising that higher rates of depression are observed among MG patients. We present a case involving a 30-year-old female patient who was admitted to the hospital for MG exacerbation and had a psychiatric consultation for worsening depression symptoms. The patient acknowledged symptoms of sad mood, crying spells, anhedonia, fatigue, insomnia, and inappropriate guilt. She admits to psychosocial stressors of her declining health, recent job loss, and low self-esteem due to weight gain. Past medical history includes a thymectomy and a total thyroidectomy that caused postsurgical-acquired hypothyroidism. She is currently on prednisone and pyridostigmine for her MG. The patient has many potential causes of her increased depressive symptoms, including her medications, psychosocial stressors, and her past medical history, in addition to her MG. However, the literature shows higher incidence rates of depression in MG patients compared to both healthy controls and controls with other comparable chronic conditions, as well as shows a positive association between increased depressive symptoms and MG severity. Thus, these findings prompt the consideration of possible physiological interplay between the two diseases and encourage further research into the association between MG and depression.

The Association Between Thyroid Stimulating Hormone and Depression: A Historical Cohort Study

OBJECTIVE

To investigate the association between thyroid-stimulating hormone (TSH) and clinically relevant depression (CRD) in a population-based study.

PATIENTS AND METHODS

Adult patients (≥18 years of age) who received care at Mayo Clinic in Rochester, Minnesota, and completed a TSH and Patient Health Questionnaire - 9 (PHQ-9) within 6 months of each other, between July 8, 2017, and August 31, 2021, were included. Demographics, medical comorbidities, thyroid function laboratory data, psychotropic medications, presence of primary thyroid disorder, thyroid hormone replacement (T4 and/or T3), and mood disorder diagnoses (using International Classification of Diseases, 10th version, Clinical Modifications codes) were extracted electronically. The primary outcome, CRD, was defined as a PHQ-9 score greater than or equal to 10. Logistic regression analysis was conducted to assess the association between TSH categories (low ≤0.3 mIU/L; normal >0.3-4.2 mIU/L; high >4.2 mIU/L) and CRD.

RESULTS

The cohort included 29,034 patients, mean age 51.4 years, 65% females, 89.9% White, and a mean body mass index of 29.9 kg/m2. The mean ± standard deviation for TSH was 3.0±8.5 mIU/L, and the mean PHQ-9 score was 6.3±6.2. After adjustment, the odds of CRD were significantly higher among the low TSH category (odds ratio, 1.37; 95% CI, 1.18-1.57; P<.001) compared with the normal TSH category, especially in people 70 years of age or younger compared with people older than 70 years of age. Subgroup analysis did not show an increase in odds of CRD among patients with subclinical/overt hypothyroidism/hyperthyroidism (after adjustment).

CONCLUSION

In this large population-based cross-sectional study, we report that low TSH was associated with higher odds of depression. Future longitudinal cohort studies are needed to investigate the relationship between thyroid dysfunction and depression as well as sex differences.

The effect of synbiotic supplementation on hypothyroidism: A randomized double-blind placebo controlled clinical trial

OBJECTIVE

We hypothesize that synbiotic supplementation could modulate the intestinal microbiota and subsequently, improve the condition of hypothyroid patients.

METHODS

Fifty-six adult hypothyroid patients were recruited to this double-blind, placebo-controlled, randomized clinical trial. The intervention was 10 weeks of synbiotic (500 mg of 109 CFU/g probiotics plus fructo-oligosaccharide, n = 28) compared to placebo (lactose, magnesium stearate, talc, and silicon dioxide, n = 28). Randomization and allocation to trial groups were carried out using random number sequences drawn from https://sealedenvelope.com/. Primary outcomes were serum thyroid stimulating hormone (TSH) and free thyroxine (FT4), and secondary outcomes were depression, quality of life, and blood pressure (BP). P-values< 0.05 were considered statistically significant.

RESULTS

Analysis on 51 patients who completed the trial showed that TSH and depression (p> 0.05) did not change significantly, while serum FT4 significantly increased in both groups (p = 0.03 and p = 0.02 in symbiotic and placebo respectively). A significant decrease in systolic BP occurred only in the synbiotic group (p = 0.05). Significant improvements occurred regarding different domains and areas of quality of life in the crude and adjusted analysis, including perceived mental health (p = 0.02), bodily pain (p = 0.02), general health perception (p = 0.002), and wellbeing (p = 0.002), which were significantly higher in the synbiotic group.

CONCLUSIONS

Ten-week supplementation with synbiotic had no favorable effect on depression and TSH, but it improved blood pressure and quality of life in patients with hypothyroidism. More trials are needed to support or reject these findings.

TRIAL REGISTRATION

IRCT20210926052583N1, Iranian Registry of Clinical Trials (IRCT), registered October 1st, 2021.

Hyperthyroidism and clinical depression: a systematic review and meta-analysis

Hyperthyroidism and clinical depression are common, and there is preliminary evidence of substantial comorbidity. The extent of the association in the general population, however, has not yet been estimated meta-analytically. Therefore we conducted this systematic review and meta-analysis (registered in PROSPERO: CRD42020164791). Until May 2020, Medline (via PubMed), PsycINFO, and Embase databases were systematically searched for studies on the association of hyperthyroidism and clinical depression, without language or date restrictions. Two reviewers independently selected epidemiological studies providing laboratory or ICD-based diagnoses of hyperthyroidism and diagnoses of depression according to operationalized criteria (e.g. DSM) or to cut-offs in established rating scales. All data, including study quality based on the Newcastle-Ottawa Scale, were independently extracted by two authors. Odds ratios for the association of clinical depression and hyperthyroidism were calculated in a DerSimonian-Laird random-effects meta-analysis. Out of 3372 papers screened we selected 15 studies on 239 608 subjects, with 61% women and a mean age of 50. Relative to euthyroid individuals, patients with hyperthyroidism had a higher chance of being diagnosed with clinical depression: OR 1.67 ([95% CI: 1.49; 1.87], I²: 6%; prediction interval: 1.40 to 1.99), a result supported in a number of sensitivity and subgroup analyses. The OR was slightly less pronounced for subclinical as opposed to overt hyperthyroidism (1.36 [1.06; 1.74] vs. 1.70 [1.49; 1.93]). This comorbidity calls for clinical awareness and its reasons need investigation and may include neurobiological mechanisms, common genetic vulnerability and a generally heightened risk for clinical depression in patients with chronic somatic disorders.

Economic and Cardiometabolic Risk Factors Are Predictors of Lower Thyroid Stimulating Hormone (TSH) Levels in Hispanic/Latinx Adults with Euthyroidism-A Community-Based Study

Thyroid hormone abnormalities are among the most common endocrine disorders comorbidly suffered alongside metabolic syndrome and type 2 diabetes mellitus (T2DM), and within the euthyroid range they may also impact other outcomes, such as mood disorders. This study aimed to observationally examine the relationship between TSH and social determinants of health and clinical measures in a euthyroid Hispanic/Latinx patient sample with a diagnosis of anxiety and/or depression disorders from a community health clinic. A needs assessment was completed using a random sample of 100 de-identified medical records of individuals who received free medical care, including mental health, at a community-based clinic. Those with low normal TSH (<2 mIU/L) compared with high normal TSH (≥2 mIU/L) had a greater odds of food insecurity (p = 0.016) and being at 100% of the federal poverty level (p = 0.015). The low normal TSH group had significantly higher fasting glucose (p = 0.046), hemoglobin A1c (p = 0.018), and total cholesterol (p = 0.034) compared with the high normal TSH group. In those with T2DM, individuals with low normal TSH had six-times greater odds of having high fasting glucose (p = 0.022) and high hemoglobin A1c (p = 0.029). These relationships warrant further study, to inform future public health policies and follow-up care for underserved and vulnerable communities.

Could the Thyroid Gland Dominate the Brain in Obsessive-Compulsive Disorder?

Thyroid hormones have an essential role in brain maturation and neuronal functioning. The comorbidity of thyroid disorders and several mental disturbances is frequently reported. We aimed to evaluate the literature on the potential relationship between thyroid disorders and obsessive-compulsive disorder (OCD) and obsessive-compulsive symptoms (OCS). We searched the literature using PUBMED, ProQuest, Google Scholar, and PsycInfo electronic databases for original studies (cross-sectional, case series, case report) on the association between thyroid dysfunctions and OCD and OCS between 1977 and 2021. Eleven studies met the inclusion criteria. Despite some methodological limitations, the OCD rates in patients with autoimmune thyroid disorders were found to be higher than the normal population in two studies. The findings on thyroid dysfunction in OCD patients were inconclusive. In the light of available data, it could be proposed that there might be a possible association between thyroid disorders and OCD. Some shared immunological mechanisms could play a role in the pathophysiology of both thyroid diseases and OCD. New research is needed to confirm this association and elucidate the underlying common mechanisms between these disorders.

Association of Hypothyroidism and Clinical Depression: A Systematic Review and Meta-analysis

IMPORTANCE

Hypothyroidism is considered a cause of or a strong risk factor for depression, but recent studies provide conflicting evidence regarding the existence and the extent of the association. It is also unclear whether the link is largely due to subsyndromal depression or holds true for clinical depression.

OBJECTIVE

To estimate the association of hypothyroidism and clinical depression in the general population.

DATA SOURCES

PubMed, PsycINFO, and Embase databases were searched from inception until May 2020 for studies on the association of hypothyroidism and clinical depression.

STUDY SELECTION

Two reviewers independently selected epidemiologic and population-based studies that provided laboratory or International Statistical Classification of Diseases and Related Health Problems diagnoses of hypothyroidism and diagnoses of depression according to operationalized criteria (eg, Diagnostic and Statistical Manual of Mental Disorders or International Statistical Classification of Diseases and Related Health Problems) or cutoffs in established rating scales.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data and evaluated studies based on the Newcastle-Ottawa Scale. Summary odds ratios (OR) were calculated in random-effects meta-analyses.

MAIN OUTCOMES AND MEASURES

Prespecified coprimary outcomes were the association of clinical depression with either hypothyroidism or autoimmunity.

RESULTS

Of 4350 articles screened, 25 studies were selected for meta-analysis, including 348 014 participants. Hypothyroidism and clinical depression were associated (OR, 1.30 [95% CI, 1.08-1.57]), while the OR for autoimmunity was inconclusive (1.24 [95% CI, 0.89-1.74]). Subgroup analyses revealed a stronger association with overt than with subclinical hypothyroidism, with ORs of 1.77 (95% CI, 1.13-2.77) and 1.13 (95% CI, 1.01-1.28), respectively. Sensitivity analyses resulted in more conservative estimates. In a post hoc analysis, the association was confirmed in female individuals (OR, 1.48 [95% CI, 1.18-1.85]) but not in male individuals (OR, 0.71 [95% CI, 0.40-1.25]).

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, the effect size for the association between hypothyroidism and clinical depression was considerably lower than previously assumed, and the modest association was possibly restricted to overt hypothyroidism and female individuals. Autoimmunity alone may not be the driving factor in this comorbidity.

Patterns of Thyroid Hormone Prescription in Patients with Bipolar or Schizoaffective Disorder: Findings from the LiSIE Retrospective Cohort Study

The prescription of thyroid hormone replacement therapy (THRT) has increased in the general population; the thyroid stimulating hormone (TSH) threshold to initiate THRT has decreased. It remains unclear whether a similar trend has occurred in patients with bipolar disorder (BD). In this work we explore patterns and trends of prescribing THRT in patients with BD or schizoaffective disorder (SZD) with an observational study and time-trend analysis in the framework of the LiSIE (Lithium-Study into Effects and Side Effects) retrospective cohort study. In most patients, THRT was initiated for subclinical hypothyroidism. The median TSH at which THRT was started was 6.0 (IQR 4.0) mIU/L and the median free serum thyroxine (fT4) at which THRT was started was 11.8 (IQR 3.9) pmol/L. The median TSH concentration at the start of THRT decreased annually with 0.10 mIU/L (p = 0.047) and was higher in patients treated with lithium than in patients treated with other mood stabilisers (p = 0.02). In conclusion, THRT was typically initiated in the context of mild or absent alterations of thyroid function tests with a decreasing TSH threshold. As THRT is rarely reversed once initiated, clinicians need to weigh up potential benefits and risks when prescribing THRT for subclinical hypothyroidism in patients with BD or SZD.

Does serum TSH level act as a surrogate marker for psychological stress and cardio-metabolic risk among adolescent and young people?

OBJECTIVES

The incidence of metabolic syndrome is increasing even at younger ages. Metabolic syndrome constitutes a group of cardiovascular risk factors that include high cholesterol, triacylglycerol, hyperglycemia, central obesity, etc., which increases the risk of cardiovascular disease, diabetes mellitus, may be even cancer. Indian students enter colleges just after crossing their adolescent age and will be exposed to greater academic stress. Psychological stress or depression is associated with transient change in thyroid hormones level or dysfunction. To explore an association among serum Thyroid Stimulating Hormone (TSH) levels, fT3:fT4 ratio, psychological stress scores, and selected known cardio-metabolic risk markers.

METHODS

Forty first year MBBS students were included. Their demographic, anthropometric variables, and the blood pressure were documented. Serum TSH, fT3, fT4, and salivary cortisol level was quantified. The stress level was assessed using Cohen Perceived Stress Scale Scoring. Data were expressed in mean ± standard deviation. Data (parametric/non-parametric) were compared by Independent unpaired ANOVA or Kruskal Wallis test whichever is appropriate. Spearmen correlation analysis was performed.

RESULTS

Serum TSH and Cohen stress score are negatively correlated (r=-0.152), but serum cortisol showed (r=0.763) a positive correlation. TSH levels and the marks obtained in the summative assessments were negatively correlated and the correlation was not statistically significant.

CONCLUSIONS

The psychological stress is associated with low serum TSH, high cortisol, and poor academic performance in first year MBBS students. Blood pressure, plasma glucose, and anthropometric measures were not associated with the psychological stress.

Thyroid Function and Mood Disorders: A Mendelian Randomization Study

Background: Observational studies suggest that even minor variations in thyroid function are associated with the risk of mood disorders, including major depressive disorder (MDD) and bipolar disorder (BD). However, it is unknown whether these associations are causal or not. We used a Mendelian randomization (MR) approach to investigate causal effects of minor variations in thyrotropin (TSH) and free thyroxine (fT4) levels on MDD and BD risk. Materials and Methods: We performed two-sample MR analyses using data from the largest publicly available genome-wide association studies on normal-range TSH (n = 54,288) and fT4 (n = 49,269) levels, MDD (170,756 cases, 329,443 controls) and BD (20,352 cases, 31,358 controls). Secondary MR analyses investigated the effects of TSH and fT4 levels on specific MDD and BD subtypes. Reverse MR was also performed to assess the effects of MDD and BD on TSH and fT4 levels. Results: There were no associations between genetically predicted TSH and fT4 levels and MDD risk, nor MDD subtypes and minor depressive symptoms. A one standard deviation increase in fT4 levels was nominally associated with an 11% decrease in the overall BD risk (odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.80-0.98, p = 0.022) and a 13% decrease in the BD type 1 risk (OR = 0.87, CI = 0.75-1.00, p = 0.047). In the reverse direction, genetic predisposition to MDD and BD was not associated with TSH nor fT4 levels. Conclusions: Variations in normal-range TSH and fT4 levels have no effects on the risk of MDD and its subtypes, and neither on minor depressive symptoms. This indicates that depressive symptoms should not be attributed to minor variations in thyroid function. Borderline associations with BD and BD type 1 risks suggest that further clinical studies should investigate the effect of thyroid hormone treatment in BD.

Association between oral health and thyroid disorders: A population-based cross-sectional study

OBJECTIVES

In this study, we aimed to determine the relationship between oral health status and thyroid dysfunction.

METHODS

A population-based cross-sectional analysis using data from the Korean National Health and Nutrition Examination Survey (KNHNES) was performed. We investigated the association between oral health-related parameters and the prevalence of thyroid diseases. In addition, the relationship between oral health status and thyroid function test (TFT) results was analyzed. One-way analysis of variances or chi-square test was used for comparisons between oral health-related parameters and presence of thyroid diseases. Univariable and multivariable logistic regression analyses were conducted to evaluate the associations between participants' characteristics including oral health-related parameters and the abnormal results of TFTs.

RESULTS

A total of 18,034 adults were surveyed. Histories of thyroid diseases were found to be more common in people who brushed their teeth frequently or used oral hygiene products. However, histories of periodontitis and community periodontal index (CPI) did not show significant associations with histories of thyroid diseases. Among 14,860 participants without history of thyroid disorders, people having higher CPI values demonstrated higher probabilities of abnormal TFTs (OR 1.381, 95% CI 1.241-1.537, p < .0001); however, statistical significance was not found after adjusting for the other variables.

CONCLUSIONS

Our study demonstrated that good oral health-related behavior was associated with more frequent thyroid disease history. High CPI showed a significant association with TFT abnormalities; however, the significance of this association became lower when other variables such as age and sex were adjusted. Further studies will be needed to determine how the control of oral health-related conditions actually has a causal relationship with thyroid disease/dysfunction through prospective cohort studies.

Low Thyroid-stimulating Hormone Levels Are Associated With Annoying Tinnitus in Adult Women: Korea National Health and Nutrition Examination Surveys

OBJECTIVE

This study aimed to investigate the relationship between thyroid function and tinnitus.

STUDY DESIGN

A cross-sectional study.

SETTING

The Korean National Health and Nutrition Examination Survey from 2013 was used.

PATIENTS AND INTERVENTIONS

A total of 1,165 participants ≥ 40 years old who were surveyed for the presence of tinnitus and underwent thyroid function tests were included. The presence of discomfort from tinnitus was defined as annoying tinnitus. The control group included participants with "no tinnitus" or "no discomfort from tinnitus." The participants were divided into the annoying tinnitus group and the control group.

MAIN OUTCOME MEASURES

The associations of free thyroxine and thyroid-stimulating hormone (TSH) with annoying tinnitus were analyzed using logistic regression with complex sampling methods. Subgroup analyses were performed according to sex.

RESULTS

The low TSH level group had 2.35-fold greater odds of annoying tinnitus than the control group (95% confidence interval  = 1.10-5.12, p = 0.027). Even in patients with a normal free thyroxine level, a low TSH level was related to 2.78-fold higher odds of annoying tinnitus (95% confidence interval  = 1.21-6.38, p = 0.016). In subgroup analyses, this association was apparent in the female subgroup. The male subgroup did not show a relationship between low TSH levels and annoying tinnitus.

CONCLUSIONS

Subclinical hyperthyroidism was related to an increased risk of annoying tinnitus. This relationship was apparent in the female subgroup.

Effect of Levothyroxine Therapy on the Development of Depressive Symptoms in Older Adults With Subclinical Hypothyroidism: An Ancillary Study of a Randomized Clinical Trial

IMPORTANCE

Previous trials on the effect of levothyroxine on depressive symptom scores in patients with subclinical hypothyroidism were limited by small sample sizes (N = 57 to 94) and potential biases.

OBJECTIVE

To assess the effect of levothyroxine on the development of depressive symptoms in older adults with subclinical hypothyroidism in the largest trial on this subject and to update a previous meta-analysis including the results from this study.

DESIGN, SETTING, AND PARTICIPANTS

This predefined ancillary study analyzed data from participants in the Thyroid Hormone Replacement for Untreated Older Adults with Subclinical Hypothyroidism (TRUST) trial, a double-blind, randomized, placebo-controlled, parallel-group clinical trial conducted from April 2013 to October 31, 2016. The TRUST trial included adults aged 65 years or older diagnosed with subclinical hypothyroidism, defined as the presence of persistently elevated thyroid-stimulating hormone (TSH) levels (4.6-19.9 mIU/L) with free thyroxine (T4) within the reference range. Participants were identified from clinical and general practitioner laboratory databases and recruited from the community in Switzerland, the Netherlands, Ireland, and the UK. This ancillary study included a subgroup of 472 participants from the Netherlands and Switzerland; after exclusions, a total of 427 participants (211 randomized to levothyroxine and 216 to placebo) were analyzed. This analysis was conducted from December 1, 2019, to September 1, 2020.

INTERVENTIONS

Randomization to either levothyroxine or placebo.

MAIN OUTCOMES AND MEASURES

Depressive symptom scores after 12 months measured with the Geriatric Depression Scale (GDS-15), with higher scores indicating more depressive symptoms (minimal clinically important difference = 2).

RESULTS

A total of 427 participants with subclinical hypothyroidism (mean [SD] age, 74.52 [6.29] years; 239 women [56%]) were included in this analysis. The mean (SD) TSH level was 6.57 (2.22) mIU/L at baseline and decreased after 12 months to 3.83 (2.29) mIU/L in the levothyroxine group; in the placebo group, it decreased from 6.55 (2.04) mIU/L to 5.91 (2.66) mIU/L. At baseline, the mean (SD) GDS-15 score was 1.26 (1.85) in the levothyroxine group and 0.96 (1.58) in the placebo group. The mean (SD) GDS-15 score at 12 months was 1.39 (2.13) in the levothyroxine and 1.07 (1.67) in the placebo group with an adjusted between-group difference of 0.15 for levothyroxine vs placebo (95% CI, -0.15 to 0.46; P = .33). In a subgroup analysis including participants with a GDS-15 of at least 2, the adjusted between-group difference was 0.61 (95% CI, -0.32 to 1.53; P = .20). Results did not differ according to age, sex, or TSH levels. A previous meta-analysis (N = 278) on the association of levothyroxine with depressive symptoms was updated to include these findings, resulting in an overall standardized mean difference of 0.09 (95% CI, -0.05 to 0.22).

CONCLUSIONS AND RELEVANCE

This ancillary study of a randomized clinical trial found that depressive symptoms did not differ after levothyroxine therapy compared with placebo after 12 months; thus, these results do not provide evidence in favor of levothyroxine therapy in older persons with subclinical hypothyroidism to reduce the risk of developing depressive symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01853579.

Thyroid Function in 35 Patients with Gitelman Syndrome

Objective. In this study, we aimed to analyze thyroid function and related risk factors for thyroid dysfunction in 35 patients with Gitelman syndrome (GS). Methods. This study included 35 patients with GS who were referred to West China Hospital of Sichuan University from Aug 2013 to Jan 2018. General patient characteristics were collected, and thyroid function was assessed. To evaluate the potential contribution of hypokalemia to thyroid dysfunction, 636 patients who were clinically diagnosed with primary aldosteronism (PA) during the same period were included as the control group; these patients were divided into a hypokalemia group ( $N=528$ ) and a normokalemia group ( $N=108$ ). Logistic regression was used to screen for significant determinants of thyroid dysfunction in the GS patients. Results. Patients with GS had a significantly different prevalence of subclinical hypothyroidism, hypothyroidism, and hyperthyroidism than patients with hypokalemic PA and normokalemic PA (28.6%, 2.9%, and 11.4% vs. 15.5%, 6.1%, and 0.7% vs. 8.3%, 4.6%, and 2.8%, $P<0.001$ ). No significant difference was observed in the distribution of thyroid function between the hypokalemic PA group and the normokalemic PA group ( $P>0.05$ ). No significant differences were seen in the positive rates of thyrotropin receptor antibody (TRAb), thyroglobulin antibody (TGAb), and thyroid peroxidase antibody (TPOAb) among the three groups ( $P>0.05$ ). In the logistic regression, only sex (OR, 7.4; 95% CI, 1.555-35.479; $P=0.012$ ) was significantly correlated with thyroid dysfunction in GS patients. Conclusion. GS is complicated with a greater rate of thyroid dysfunction than primary aldosteronism. The risk of thyroid dysfunction in female patients with GS is higher than that in male patients.

An individual participant data analysis of prospective cohort studies on the association between subclinical thyroid dysfunction and depressive symptoms

In subclinical hypothyroidism, the presence of depressive symptoms is often a reason for starting levothyroxine treatment. However, data are conflicting on the association between subclinical thyroid dysfunction and depressive symptoms. We aimed to examine the association between subclinical thyroid dysfunction and depressive symptoms in all prospective cohorts with relevant data available. We performed a systematic review of the literature from Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library from inception to 10th May 2019. We included prospective cohorts with data on thyroid status at baseline and depressive symptoms during follow-up. The primary outcome was depressive symptoms measured at first available follow-up, expressed on the Beck's Depression Inventory (BDI) scale (range 0-63, higher values indicate more depressive symptoms, minimal clinically important difference: 5 points). We performed a two-stage individual participant data (IPD) analysis comparing participants with subclinical hypo- or hyperthyroidism versus euthyroidism, adjusting for depressive symptoms at baseline, age, sex, education, and income (PROSPERO CRD42018091627). Six cohorts met the inclusion criteria, with IPD on 23,038 participants. Their mean age was 60 years, 65% were female, 21,025 were euthyroid, 1342 had subclinical hypothyroidism and 671 subclinical hyperthyroidism. At first available follow-up [mean 8.2 (± 4.3) years], BDI scores did not differ between participants with subclinical hypothyroidism (mean difference = 0.29, 95% confidence interval =  - 0.17 to 0.76, I² = 15.6) or subclinical hyperthyroidism (- 0.10, 95% confidence interval =  - 0.67 to 0.48, I² = 3.2) compared to euthyroidism. This systematic review and IPD analysis of six prospective cohort studies found no clinically relevant association between subclinical thyroid dysfunction at baseline and depressive symptoms during follow-up. The results were robust in all sensitivity and subgroup analyses. Our results are in contrast with the traditional notion that subclinical thyroid dysfunction, and subclinical hypothyroidism in particular, is associated with depressive symptoms. Consequently, our results do not support the practice of prescribing levothyroxine in patients with subclinical hypothyroidism to reduce the risk of developing depressive symptoms.

Association of Thyroid Status with Health-Related Quality of Life in Korean Older Adults

Background

While hypothyroidism is associated with negative health effects in the general population, older adults with hypothyroidism have better physical function and comparable rates of depression and cognitive impairment relative to their euthyroid counterparts. The aim of this study was to investigate the association between thyroid status and health-related quality of life in Korean older adults.

Methods

In this population-based cross-sectional study, 1,060 adults aged over 60 years were classified by thyroid status into four groups based on their thyroid stimulating hormone (TSH) and free T4 values: overt hypothyroid, subclinical hypothyroid, euthyroid, and subclinical hyperthyroid. The main outcome measure was self-reported health-related quality of life based on the three-level version of the EuroQol-5 dimension (EQ-5D), with utility values of -0.171 and 1.000 corresponding to the worst and best health statuses, respectively. The adjusted means of the EQ-5D three-level version utility values according to thyroid status were determined using a linear regression analysis.

Results

In the adjusted analysis, the overt hypothyroid group showed significantly higher EQ-5D three-level version utility values than did the euthyroid group (0.998 vs. 0.908, P=0.000). In the subgroup analyses by sex, the overt hypothyroid group also showed significantly higher EQ-5D three-level version utility values for both men and women than did the euthyroid group (0.998 vs. 0.940, P=0.008; 0.983 vs. 0.882, P=0.001).

Conclusion

Asymptomatic Korean older adults aged over 60 years with TSH and free T4 values corresponding to overt hypothyroidism have better health-related quality of life than their euthyroid counterparts.

Subclinical thyroid dysfunction and depressive symptoms: protocol for a systematic review and individual participant data meta-analysis of prospective cohort studies

INTRODUCTION

Prospective cohort studies on the association between subclinical thyroid dysfunction and depressive symptoms have yielded conflicting findings, possibly because of differences in age, sex, thyroid-stimulating hormone cut-off levels or degree of baseline depressive symptoms. Analysis of individual participant data (IPD) may help clarify this association.

METHODS AND ANALYSIS

We will conduct a systematic review and IPD meta-analysis of prospective studies on the association between subclinical thyroid dysfunction and depressive symptoms. We will identify studies through a systematic search of the literature in the Ovid Medline, Ovid Embase, Cochrane Central Register of Controlled Trials (CENTRAL) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases from inception to April 2019 and from the Thyroid Studies Collaboration. We will ask corresponding authors of studies that meet our inclusion criteria to collaborate by providing IPD. Our primary outcome will be depressive symptoms at the first available individual follow-up, measured on a validated scale. We will convert all the scores to the Beck Depression Inventory scale. For each cohort, we will estimate the mean difference of depressive symptoms between participants with subclinical hypothyroidism or hyperthyroidism and control adjusted for depressive symptoms at baseline. Furthermore, we will adjust our multivariable linear regression analyses for age, sex, education and income. We will pool the effect estimates of all studies in a random-effects meta-analysis. Heterogeneity will be assessed by I². Our secondary outcomes will be depressive symptoms at a specific follow-up time, at the last available individual follow-up and incidence of depression at the first, last and at a specific follow-up time. For the binary outcome of incident depression, we will use a logistic regression model.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as primary data will not be collected. Our findings will have considerable implications for patient care. We will seek to publish this systematic review and IPD meta-analysis in a high-impact clinical journal.

PROSPERO REGISTRATION NUMBER

CRD42018091627.

Thyroid hormones treatment for subclinical hypothyroidism: a clinical practice guideline

CLINICAL QUESTION

What are the benefits and harms of thyroid hormones for adults with subclinical hypothyroidism (SCH)? This guideline was triggered by a recent systematic review of randomised controlled trials, which could alter practice.

CURRENT PRACTICE

Current guidelines tend to recommend thyroid hormones for adults with thyroid stimulating hormone (TSH) levels >10 mIU/L and for people with lower TSH values who are young, symptomatic, or have specific indications for prescribing.

RECOMMENDATION

The guideline panel issues a strong recommendation against thyroid hormones in adults with SCH (elevated TSH levels and normal free T4 (thyroxine) levels). It does not apply to women who are trying to become pregnant or patients with TSH >20 mIU/L. It may not apply to patients with severe symptoms or young adults (such as those ≤30 years old).

HOW THIS GUIDELINE WAS CREATED

A guideline panel including patients, clinicians, and methodologists produced this recommendation in adherence with standards for trustworthy guidelines using the GRADE approach.

THE EVIDENCE

The systematic review included 21 trials with 2192 participants. For adults with SCH, thyroid hormones consistently demonstrate no clinically relevant benefits for quality of life or thyroid related symptoms, including depressive symptoms, fatigue, and body mass index (moderate to high quality evidence). Thyroid hormones may have little or no effect on cardiovascular events or mortality (low quality evidence), but harms were measured in only one trial with few events at two years' follow-up.

UNDERSTANDING THE RECOMMENDATION

The panel concluded that almost all adults with SCH would not benefit from treatment with thyroid hormones. Other factors in the strong recommendation include the burden of lifelong management and uncertainty on potential harms. Instead, clinicians should monitor the progression or resolution of the thyroid dysfunction in these adults. Recommendations are made actionable for clinicians and their patients through visual overviews. These provide the relative and absolute benefits and harms of thyroid hormones in multilayered evidence summaries and decision aids available in MAGIC (https://app.magicapp.org/) to support shared decisions and adaptation of this guideline.

Subclinical Hypothyroidism and Depression: A Systematic Review and Meta-Analysis

Background: Thyroid function is closely associated with neuropsychological functions, including mental state and cognitive functions. Although thyroid function is routinely examined in persons with depressive symptom, the association between subclinical hypothyroidism (SCH) and depression remains inconclusive. Objective: This systematic review and meta-analysis aimed to evaluate the risk of depression in persons with SCH. Methods: The PubMed, Embase, and Web of Science databases were searched up to August 2018. The primary outcome was the prevalence of depression, as evaluated by various types of self-reported depression scales. Odds ratios (ORs) were calculated to compare the risk of depression between persons with SCH and those with euthyroidism. Results: Twenty-one studies were included in the systematic review, with a total of 103,375 subjects from 7 studies being pooled for the meta-analysis to evaluate the risk of depression. The meta-analysis showed that persons with SCH had a significantly elevated risk of depression than persons with euthyroidism (OR = 1.78, 95% confidence interval [CI]: 1.11-2.86, P = 0.02). No publication bias was found, as indicated by Egger's test (t = -0.49, P = 0.647) and Begg's test (z = -0.15, P = 0.881). In addition, the funnel plot showed a symmetric distribution. Conclusions: This meta-analysis demonstrated that SCH was positively associated with the risk of depression, especially in persons above 50 years of age, suggesting it is necessary to pay close attention to depressive symptoms in persons with SCH.