Effects of Thyroid Status on Regional Brain Volumes: A Diagnostic and Genetic Imaging Study in UK Biobank

Impaired sensitivity to thyroid hormones is associated with different grades of hypertension: A multicenter cross-sectional study

BACKGROUND AND AIM

Accumulating evidence suggests a potential link between thyroid function with hypertension. However, the research results are limited, and there is no research to explore the relationship between central and peripheral thyroid hormones (THs) sensitivity and different grades of hypertension in patients with coronary heart disease (CHD). This study aims to prove the complex interaction between thyroid system and blood pressure, and provides new ideas for the assessment of hypertension in patients with CHD.

METHODS AND RESULTS

Calculate parameters representing central and peripheral sensitivity to THs. Logistic regression analysis was used to analyze the relationship between central and peripheral THs sensitivity of CHD patients and different grades of hypertension, especially in different ages, sexes, blood glucose levels, smoking, and drinking statuses. Among the 34,310 participants, 19,610 (57.16 %) were diagnosed with hypertension. The risk of hypertension and TSHI (OR: 0.88; 95 % CI: 0.87-0.90; P < 0.001), TT4RI (OR: 0.998; 95 % CI: 0.998-0.999; P < 0.001), TFQI (OR: 0.63; 95 % CI: 0.60-0.67; P < 0.001), PTFQI (OR: 0.63; 95 % CI: 0.59-0.67; P < 0.001) was negatively associated. The risk of hypertension was positively associated with FT3/FT4 (OR: 1.20; 95 % CI: 1.17-1.22; P < 0.001). After stratified analysis, these associations remained significant at different ages, sexes, blood glucose levels, grades of hypertension, smoking, and drinking statuses (P < 0.001).

CONCLUSIONS

This study shows that the decrease in central THs sensitivity index and the increase in peripheral THs sensitivity index are associated with a higher risk of hypertension in CHD patients.

Gray matter reduction is associated with cognitive dysfunction in depressed patients comorbid with subclinical hypothyroidism

Introduction

To explore the association between regional gray matter volume (GMV) and cognitive impairments and ascertain whether the regional brain alterations related to cognitive impairments occur in major depressive disorder (MDD) patients with comorbid subclinical hypothyroidism (SHypo).

Methods

We enrolled 32 MDD patients, 32 MDD patients with comorbid SHypo, and 32 normal controls and subjected them to thyroid function tests, neurocognitive tests, and magnetic resonance imaging (MRI). Using voxel-based morphometry (VBM) analysis, we examined the pattern of gray matter (GM) in these participants. We also used ANOVA to detect group differences and partial correlation to explore the potential association between GMV alterations and cognitive tests in comorbid patients.

Results

The comorbid patients exhibited significantly smaller GMV in the right middle frontal gyrus (MFG) than the non-comorbid group. Furthermore, the partial correlation analysis showed that GMV of the right MFG was associated with poor executive function (EF) performance in comorbid patients.

Conclusion

These findings provide valuable insight into the relationship between the alteration of GMV and cognitive dysfunction of MDD patients with comorbid SHypo.

Serum TSH Levels are Associated with Hyperactivity Behaviors in Children with Attention Deficit/Hyperactivity Disorder

Objective

Previous studies indicated that maternal thyroid dysfunction increase the offspring's risk for attention deficit/hyperactivity disorder (ADHD). However, the relationship between thyroid function and symptoms in children with ADHD remains unclear.

Methods

A total of 49 children with ADHD were enrolled. The Conners 3 scale was used to estimate the symptoms associated with ADHD. Correlation between thyroid hormones and the scores of the Conners 3 scale was evaluated by Pearson correlation analysis. Then, ADHD children were divided into two groups according to the hyperactivity index (HI) of the Conners 3 scale: ADHD children with hyperactivity behaviors (HB) (HI > 1.5) and ADHD children without HB (HI < 1.5). The demographic characteristics, thyroid hormones, and routine laboratory parameters between the two groups were collected. To distinguish HI-related factors, a univariate analysis and a binary logistic regression predictive model were used. The discriminative ability of thyroid stimulating hormone (TSH) in predicting ADHD children with HB from ADHD children without HB was investigated using the receiver operating characteristic (ROC) curve method.

Results

The levels of TSH were positively correlated to the scores of the Conners 3 scale (r = 0.338, P = 0.033) and HI (r = 0.371, P = 0.019). Moreover, the levels of TSH, serum ferritin, and lactic acid were significantly increased in ADHD children with HB compared to ADHD children without HB (all P < 0.05). Furthermore, the results of binary logistic regression found that TSH (OR 2.243 (CL 1.052-4.783)) and lactic acid (OR 1.018 (CI 1.003-1.032)) were independently associated with HI. Additionally, ROC analysis indicated the potential diagnostic value of TSH in discriminating ADHD children with HB from ADHD children without HB with an AUC of 0.684.

Conclusion

These results suggested that the serum TSH levels may be related to the HB in children with ADHD.

New Horizons: the value of UK Biobank to research on endocrine and metabolic disorders

UK Biobank is an intensively characterized prospective study of 500 000 men and women, aged 40 to 69 years when recruited, between 2006 and 2010, from the general population of the United Kingdom. Established as an open-access resource for researchers worldwide to perform health research that is in the public interest, UK Biobank has collected (and continues to collect) a vast amount of data on genetic, physiological, lifestyle, and environmental factors, with prolonged follow-up of heath conditions through linkage to administrative electronic health records. The study has already demonstrated its unique value in enabling research into the determinants of common endocrine and metabolic diseases. The importance of UK Biobank, heralded as a flagship project for UK health research, will only increase over time as the number of incident disease events accrue, and the study is enhanced with additional data from blood assays (such as whole-genome sequencing, metabolomics, and proteomics), wearable technologies (including physical activity and cardiac monitors), and body imaging (magnetic resonance imaging and dual-energy X-ray absorptiometry). This unique research resource is likely to transform our understanding of the causes, diagnosis, and treatment of many endocrine and metabolic disorders.

Brain Fog in Hypothyroidism: What Is It, How Is It Measured, and What Can Be Done About It

Background: Some levothyroxine (LT4)-treated hypothyroid patients report a constellation of persistent and distressing cognitive symptoms that has been termed brain fog. This narrative review focuses on attempts to define and measure hypothyroid-associated brain fog, summarize possible etiologies and contributing factors, present treatment options, and propose avenues for future research. Methods: Published literature was reviewed to summarize available information on patient-reported symptoms associated with brain fog in hypothyroidism, as well as objective evidence of impairment based on neurocognitive testing and functional imaging studies. Given the limited information specific for hypothyroid-associated brain fog, relevant data from other medical conditions associated with brain fog were also reviewed and incorporated into recommendations for clinical care and future research areas. Results: Hypothyroid-associated brain fog has not been well defined or quantitated, and the underlying pathophysiology is unclear. Symptoms vary among patients but commonly include fatigue, depressed mood, and cognitive difficulties in the areas of memory and executive function. Symptoms often predate the diagnosis of hypothyroidism, and the magnitude of cognitive impairment can range from mild to severe. Regardless of severity, these symptoms are associated with impaired quality of life and cause dissatisfaction with treatment, so often lead to requests for alternate therapies. Disease-specific and psychological factors impact the experience of brain fog in complex ways, including potential limitations in LT4 monotherapy, self-knowledge of a disease state, and expectations for therapeutic effects. Conclusions: Brain fog is a variable symptom complex in people with hypothyroidism, causing significant distress and diminished quality of life. In the absence of proven therapies, individualized treatment plans are recommended, which incorporate thyroid-specific, general medical, and psychosocial approaches. In particular, cognitive rehabilitation is an underutilized technique that is beneficial in other medical conditions associated with brain fog and could improve symptoms in hypothyroid people. The limitations in our current knowledge and questions presented throughout this review highlight a major need for clinical research in this understudied area. Future research should include attention to standardization of survey instruments to quantitate brain fog in hypothyroid people, as well as rigorously designed intervention studies.

Growth Hormone and Thyroid Function in Children With Attention Deficit Hyperactivity Disorder Undergoing Drug Therapy

CONTEXT

The trends in hormone indices of children with attention deficit hyperactivity disorder (ADHD) who received long-term medication treatment remains controversial.

OBJECTIVE

This prospective study aimed to examine the changes in the growth hormone and thyroid hormone systems among children with ADHD undergoing various medication treatments.

METHODS

In total, 118 children who were diagnosed with ADHD and were drug-naive were observed naturalistically over 12 months. Of them, 22 did not receive any medication, while 39, 40, and 17 were treated with low doses of short-acting methylphenidate (MPH) (14 ± 6.7 mg/day), osmotic-release oral system (OROS) long-acting MPH (32 ± 9.6 mg/day), and atomoxetine (29.2 ± 9.7 mg/day), respectively. Blood samples were obtained at both the baseline and the endpoint (month 12) to measure serum levels of insulin-like growth factor 1 (IGF-1), IGF binding protein 3 (IGFBP-3), prolactin, thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and free T4.

RESULTS

Trends for IGF-1, IGFBP-3, prolactin, TSH, T3, T4, and free T4 levels were similar among the 4 groups. Changes in serum levels of IGF-1 were positively correlated with changes in height and weight of all the children with ADHD. However, patients who received MPH treatment had less body weight gain than the nonmedicated group. The ratio of MPH doses to body weight was inversely correlated with the increment in height.

CONCLUSION

There were no changes in thyroid or growth hormones associated with the low doses of ADHD medications used in this study within 1 year's duration. Nonetheless, patients' growth and the appropriateness of drug dosage should be closely monitored.

Interrelationships among growth hormone, thyroid function, and endocrine-disrupting chemicals on the susceptibility to attention-deficit/hyperactivity disorder

Abnormal growth hormones and thyroid function may be linked to pathophysiology of attention-deficit/hyperactivity disorder (ADHD). Phthalates and bisphenol-A (BPA), two endocrine-disrupting chemicals (EDCs), may affect the human endocrine system. In this study, we aimed to perform a comprehensive investigation of whether growth hormone, thyroid function, and EDCs exhibited differential levels between ADHD patients and healthy controls. In total, 144 children with ADHD and 70 healthy control subjects were enrolled. Their endocrine systems were evaluated using the serum levels of insulin-like growth factor-1 (IGF-1), IGF-binding protein-3 (IGFBP-3), thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and Free T4. The urinary levels of EDCs, including monoethyl phthalate (MEP), mono-methyl phthalate (MMP), monoethylhexyl phthalate (MEHP), mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), and BPA, were also examined. Patients with ADHD had lower IGF-1 levels than healthy controls (p = 0.003), but we observed no significant difference in IGFBP-3, TSH, T3, T4, or Free T4. Compared to the control group, patients with ADHD demonstrated higher MEHP levels (p = 0.043), MnBP (p = 0.033), and MBzP (p = 0.040). Furthermore, MEHP levels (p < 0.001) and BPA levels (p = 0.041) were negatively correlated with IGF-1 levels, while IGF-1 levels were negatively correlated with principal components consisting of ADHD clinical symptoms and neuropsychological performance variables. We suggest that MEHP exposure may be associated with decreased serum levels of IGF-1 and increased risk of ADHD. The mechanism underlying this association may be important for protecting children from environmental chemicals that adversely affect neurodevelopment.

Impaired sensitivity to thyroid hormones and carotid plaque in patients with coronary heart disease: A RCSCD-TCM study in China

CONTEXT

Previous studies on the association between thyroid function and carotid plaque have shown contradictory results, which may be attributable to the sensitivity to thyroid hormone indices. This study aimed to analyze the association between thyroid hormone sensitivity and risk of carotid plaque in patients with coronary heart disease (CHD) and further explore this association according to sex, age, smoking, and drinking status.

METHODS

This large-scale, multi-center, retrospective, cross-sectional study included 6679 patients with CHD (age 35-75). Central sensitivity to thyroid hormone was evaluated by the thyroid feedback quantile-based index (TFQI), parametric thyroid feedback quantile-based index (PTFQI), thyroid-stimulating hormone index (TSHI), and thyrotroph thyroxine resistance index (TT4RI). Peripheral sensitivity to thyroid hormone was assessed by free triiodothyronine/free thyroxine (FT3/FT4) ratio. Taking no carotid plaque as a reference, this study used logistic regression to analyze the association between central and peripheral thyroid hormone sensitivity and carotid plaque in patients with CHD.

RESULTS

Of the 6679 patients with CHD, 4843 (72.50%) had carotid plaque. In the multi-adjusted models, the TFQI (odds ratio [OR]: 1.50; 95% confidence interval [CI]: 1.26-1.78; P < 0.001), PTFQI (OR: 1.76; 95% CI: 1.46-2.12; P < 0.001), TSHI (OR: 1.21; 95% CI: 1.10-1.33; P < 0.001), and TT4RI (OR: 1.00; 95% CI: 1.00-1.01; P = 0.003) were positively associated with the risk of carotid plaque. Compared with that in females and people > 60 years, the OR value for carotid plaque was higher in males and people ≤ 60 years. Similarly, smokers and drinkers had higher OR values for carotid plaque than non-smokers and non-drinkers. Conversely, FT3/FT4 ratio (OR: 0.75; 95% CI: 0.70-0.81; P < 0.001) was negatively associated with carotid plaque, and the OR value for carotid plaque was lower in males, patients ≤ 60 years, smokers, and drinkers.

CONCLUSION

This study showed that thyroid hormone sensitivity is significantly associated with carotid plaque in patients with CHD. This association is more significant in males, patients ≤ 60 years, smokers, and drinkers.

Myxedema coma complicated by bilateral hygromas

SUMMARY

Myxedema coma is an important differential diagnosis in critically ill patients. Early diagnosis and treatment are paramount but challenging due to a lack of diagnostic criteria. We report a case about a patient who suffered from untreated hypothyroidism for several years. Before the correct diagnosis was made, he was admitted three times due to severe constipation. Eventually, he developed myxedema coma in connection with a urinary tract infection. The course was complicated by recurrent seizures, and neuroimaging showed bilateral hygromas. Hormone replacement therapy resulted in complete recovery and regression of hygromas. To the best of our knowledge, this is the first time hygroma is reported in association with myxedema coma.

LEARNING POINTS

Myxedema coma is a difficult diagnosis to make due to a lack of diagnostic criteria. Cardinal features include hypothermia, bradycardia, gastrointestinal symptoms, pericardial/pleural effusions and affection of CNS. Anemia and hyponatremia are common. In case of suspected myxedema coma, neuroimaging should be a part of the evaluation in most cases. There is a possible association between longstanding/severe hypothyroidism and hygroma.

The Correlation Between Thyroid Function, Frontal Gray Matter, and Executive Function in Patients With Major Depressive Disorder

The present study was aimed to investigate the relationships between serum thyroid hormones (THs), frontal gray matter volume, and executive function in selected patients with major depressive disorder (MDD). One hundred and four MDD patients and seventy-five healthy controls (HCs) were subjected to thyroid-stimulating hormone (TSH), free Triiodothyronine (fT3), free Thyroxine (fT4), and executive function tests and underwent structural magnetic resonance imaging (MRI). Voxel-based morphometry (VBM) analysis was performed to compare group differences in the gray matter for the frontal lobe. Furthermore, mediation analysis was used to investigate whether gray matter volumes of the frontal gyrus mediated the relationship between serum THs and executive function in MDD patients. MDD patients exhibited significant gray matter volume reduction in several brain regions, including the left rectus, right middle frontal cortex, and left middle frontal cortex. Serum TSH levels are positively associated with altered regional gray matter volume patterns within MFG and executive function. Importantly, gray matter in the right MFG was a significant mediator between serum TSH levels and executive function. These findings expand our understanding of how thyroid function affects brain structure changes and executive function in MDD patients.