Thyroid Disorders and Dementia Risk: A Nationwide Population-Based Case-Control Study

Multi-omics data integration reveals novel genes related to autoimmune hypothyroidism in the brain: A molecular basis for the brain-thyroid axis

BACKGROUND

The mechanisms underlying the complex relationship between autoimmune hypothyroidism and neurological disorders remain unclear. We conducted a comprehensive analysis of associations between alternative splicing, transcriptomics, and proteomics data and autoimmune hypothyroidism.

METHODS

Splicing-wide association studies (SWAS), proteome-wide association studies (PWAS), and transcriptome-wide association studies (TWAS) were used to identify genes and proteins that regulate autoimmune hypothyroidism within the brain axis. We performed TWAS on GTEx V8 thyroid tissue data to identify autoimmune hypothyroidism-associated thyroid axis genes. A FUSION analysis of overlapping genes in the brain and thyroid axes and brain splicing weights was conducted to determine the influence of alternative splicing in the brain on thyroid tissue gene expression.

RESULTS

SWAS identified 223 alternative splicing events, TWAS identified 270 genes, and PWAS revealed five genes (FDPS, PPIL3, PEX6, MMAB, and ALDH2) encoding proteins associated with autoimmune hypothyroidism. Neuroimaging analyses revealed distinct brain-imaging phenotypes associated with these five genes. TWAS of thyroid tissue identified four genes (FDPS, PPIL3, MMAB, and ALDH2) associated with the brain axis related to thyroid tissue. A FUSION analysis indicated that alternative splicing changes in ALDH2 in brain tissue influenced its expression in thyroid tissue.

CONCLUSION

Integrating brain splicing, proteomic, and transcriptomic data supports the association between specific genes and proteins in the brain and autoimmune hypothyroidism. Additionally, ALDH2 alternative splicing in brain tissue influences its thyroid tissue expression. These findings provide new insights into the molecular basis of autoimmune hypothyroidism, facilitating future pathogenesis research.

Sociodemographic and health predictors of adherence to self-administered computerized cognitive assessment

Introduction

Cognitive assessment is essential to detect early cognitive decline and guide interventions. Self-administered computerized assessment is a promising option for periodic cognitive screening in the general population. One of the most critical challenges to implementing cognitive screening in at risk populations is participants' adherence. However, there is insufficient evidence to determine which factors are essential for adherence to long-term digital cognitive screening.

Aims

This study aims to investigate potential sociodemographic and health predictors of adherence to a self-administered web-based cognitive monitoring, the Brain on Track (BoT), in the general population.

Methods

Participants (n = 347) were recruited from the general community. The participants were asked to perform one BoT test every 3 months for cognitive screening and were followed at two time points, namely, 1-year and 3- to 6-year follow-up. Regression models were used to investigate sociodemographic and health predictors of adherence to BoT use at 1 year and up to 6 years.

Results

Being older positively affects adherence to periodic cognitive screening for both follow-up periods. Being a female, having more years of formal education, presenting more BoT baseline correct answers and fewer BoT baseline incorrect answers, and reporting memory complaints positively affect adherence to periodic screening at 3 to 6 years of follow-up but not at 1-year follow-up.

Discussion

The identified determinants of adherence can be considered when planning long-term cognitive screening protocols to increase adherence. Specific strategies could be helpful to improve the adherence of participants who adhere less.

The association between thyroid function and insulin resistance as measured by the metabolic score for insulin resistance (METS-IR): insights from NHANES 2007-2012

BACKGROUND

Altered thyroid function has been linked to insulin resistance (IR), but its relationship with the Metabolic Score for Insulin Resistance (METS-IR), a novel non-insulin-based index of IR, remains unclear. This study aimed to investigate the association between thyroid function status and METS-IR in a U.S.

POPULATION

METHODS

This cross-sectional study utilized data from 6,507 adults (aged ≥ 20 years) participating in the National Health and Nutrition Examination Survey from 2007 to 2012. Thyroid function status was categorized into five groups based on thyroid-stimulating hormone and free thyroxine levels. METS-IR was calculated from measures of fasting glucose, triglycerides, high-density lipoprotein cholesterol (HDL-C), and body mass index (BMI). Multivariate regression analyzed the relationship between thyroid status and METS-IR after adjusting for potential confounders.

RESULTS

Higher thyroid-stimulating hormone levels were positively associated with METS-IR (β = 0.003, 95% CI 0.001-0.004, p = 0.021). Subclinical hypothyroidism in males and subclinical hyperthyroidism in females showed significant correlations with higher METS-IR. Thyroid peroxidase antibodies (TPO Ab) positivity strengthened the association between overt hypothyroidism and METS-IR.

CONCLUSIONS

This study demonstrates significant associations between thyroid function status, particularly subclinical thyroid dysfunction, and insulin resistance as measured by METS-IR in a U.S.

POPULATION

Thyroid status may serve as an early marker of insulin resistance risk.

Alzheimer's disease: a comprehensive review of epidemiology, risk factors, symptoms diagnosis, management, caregiving, advanced treatments and associated challenges

Background

Alzheimer's disease (AD) is a chronic, progressive neurodegenerative disorder characterized by cognitive decline, memory loss, and impaired reasoning. It is the leading cause of dementia in older adults, marked by the pathological accumulation of amyloid-beta plaques and neurofibrillary tangles. These pathological changes lead to widespread neuronal damage, significantly impacting daily functioning and quality of life.

Objective

This comprehensive review aims to explore various aspects of Alzheimer's disease, including its epidemiology, risk factors, clinical presentation, diagnostic advancements, management strategies, caregiving challenges, and emerging therapeutic interventions.

Methods

A systematic literature review was conducted across multiple electronic databases, including PubMed, MEDLINE, Cochrane Library, and Scopus, from their inception to May 2024. The search strategy incorporated a combination of keywords and Medical Subject Headings (MeSH) terms such as "Alzheimer's disease," "epidemiology," "risk factors," "symptoms," "diagnosis," "management," "caregiving," "treatment," and "novel therapies." Boolean operators (AND, OR) were used to refine the search, ensuring a comprehensive analysis of the existing literature on Alzheimer's disease.

Results

AD is significantly influenced by genetic predispositions, such as the apolipoprotein E (APOE) ε4 allele, along with modifiable environmental factors like diet, physical activity, and cognitive engagement. Diagnostic approaches have evolved with advances in neuroimaging techniques (MRI, PET), and biomarker analysis, allowing for earlier detection and intervention. The National Institute on Aging and the Alzheimer's Association have updated diagnostic criteria to include biomarker data, enhancing early diagnosis.

Conclusion

The management of AD includes pharmacological treatments, such as cholinesterase inhibitors and NMDA receptor antagonists, which provide symptomatic relief but do not slow disease progression. Emerging therapies, including amyloid-beta and tau-targeting treatments, gene therapy, and immunotherapy, offer potential for disease modification. The critical role of caregivers is underscored, as they face considerable emotional, physical, and financial burdens. Support programs, communication strategies, and educational interventions are essential for improving caregiving outcomes. While significant advancements have been made in understanding and managing AD, ongoing research is necessary to identify new therapeutic targets and enhance diagnostic and treatment strategies. A holistic approach, integrating clinical, genetic, and environmental factors, is essential for addressing the multifaceted challenges of Alzheimer's disease and improving outcomes for both patients and caregivers.

S, S. M, S. Sundarakumar J, Stezin A, Issac TG. Prevalence of hypothyroidism in older adults and its association with cognition: a cross-sectional study from a South Indian ageing urban cohort

The study conducted on a South Indian urban cohort aimed to emphasize the prevalence and patterns of hypothyroidism and its association with cognition among individuals aged 45 years and above. A cross-sectional design was adopted, utilizing data from the Tata Longitudinal Study of Aging cohort, comprising 1201 non-demented participants in Bangalore, South India. The study contains detailed clinical assessments, including medical history, physical examination and cognitive tests such as the COGNITO battery, Hindi Mental State Examination and Addenbrooke's Cognition Examination III. Biochemical tests were utilized to quantify plasma levels of thyroid-stimulating hormone, triiodothyronine and thyroxine. Participants were categorized based on medication history and thyroid hormone levels. The study findings showed a 17.69% prevalence of hypothyroidism, with 6.22% being classified as overt hypothyroidism and 93.78% as subclinical hypothyroidism. The prevalence was significantly higher in females compared with males (P = 0.043). Individuals with hypothyroidism are more frequently diagnosed with mild cognitive impairment than people with euthyroid (P = 0.008). Furthermore, on the classification based on thyroid medication history, the ineffective treatment group performed poorer in Addenbrooke's Cognition Examination III fluency (P = 0.006), auditory attention (P = 0.001) and form matching (P = 0.024) tasks compared with the adequately treated group. The partially treated group performed poorer in visual attention (P = 0.005) and vocabulary (P = 0.043) compared with the effectively treated group. The study identified a notable prevalence of hypothyroidism in the cohort, with females exhibiting a higher prevalence. Our study suggests that the timely management of thyroid disorders with medications is crucial not only to prevent hormonal imbalances but also to improve cognitive functioning.

Moderating effects of body composition biomarkers on the relationship between thyroid hormones and cognitive performance in euthyroid older adults: insights from NHANES data

Background

Thyroid hormones are essential for cognitive function and can impact cognitive performance even in euthyroid individuals. This study investigates how thyroid hormones influence cognitive performance in the elderly and whether body composition biomarkers moderate this relationship. The aim is to determine if lifestyle interventions should prioritize weight loss, overall body fat reduction, or abdominal fat loss.

Methods

We analyzed data from the NHANES 2011-2012 dataset, focusing on thyroid hormone levels, cognitive performance, and body composition metrics in euthyroid individuals aged 60 to 80 years. A total of 573 participants were included in the analysis. Pearson correlation analyses were conducted to evaluate the associations between thyroid hormone indicators and cognitive performance metrics. Ordinal logistic regression and linear regression analyses were used to determine the predictive capacity of thyroid hormones on cognitive functions, adjusting for potential confounders such as age, gender, and education level. Statistical analyses were performed using R Studio and Stata, utilizing Pearson correlation, ordinal logistic regression, and linear regression methods.

Results

Significant correlations were observed between short-term memory and TT3 (r = 0.111, p = 0.018), TSHI (r = -0.121, p = 0.010), and TFQI (r = -0.107, p = 0.023); delayed memory and FT3 (r = 0.143, p = 0.003), TT3 (r = 0.146, p = 0.002), and TSHI (r = -0.125, p = 0.009); and executive function with FT4 (r = -0.141, p = 0.003) and the FT3/FT4 ratio (r = 0.137, p = 0.004). Although thyroid indicators did not independently predict short-term memory (OR = 0.006, p = 0.116), they were statistically significant for delayed memory with FT3 (OR = 0.642, p = 0.017) and TT3 (OR = 0.010, p = 0.015). Linear regression analysis indicated that FT4 (t = -2.99, p = 0.003) and the FT3/FT4 ratio (t = 2.91, p = 0.004) were significant predictors of executive function. Hierarchical regression analyses revealed that BMI and waist circumference (WWI) significantly moderated the relationship between thyroid function and short-term memory (BMI: z = 2.44, p = 0.015; WWI: z = -2.19, p = 0.029). BMI also moderated the models for delayed memory (z = 2.11, p = 0.035), while RFM and C-index did not exhibit significant moderating effects. No moderators were identified in the relationship between executive function and thyroid hormones.

Conclusion

This study underscores the significant influence of higher BMI and waist circumference on the relationship between thyroid function and memory performance. In contrast, body composition indicators such as RFM and C-index do not appear to significantly affect cognitive function related to thyroid levels, highlighting the importance of fat distribution in cognitive health assessments.

Integration of genomic and transcriptomic layers in RNA-Seq data leads to protein interaction modules with improved Alzheimer's disease associations

Alzheimer's disease (AD) is the most common neurodegenerative disease, and it is currently untreatable. RNA sequencing (RNA-Seq) is commonly used in the literature to identify AD-associated molecular mechanisms by analysing changes in gene expression. RNA-Seq data can also be used to detect genomic variants, enabling the identification of the genes with a higher load of deleterious variants in patients compared with controls. Here, we analysed AD RNA-Seq datasets to obtain differentially expressed genes and genes with a higher load of pathogenic variants in AD, and we combined them in a single list. We mapped these genes on a human protein-protein interaction network to discover subnetworks perturbed by AD. Our results show that utilizing gene pathogenicity information from RNA-Seq data positively contributes to the disclosure of AD-related mechanisms. Moreover, dividing the discovered subnetworks into highly connected modules reveals a clearer picture of altered molecular pathways that, otherwise, would not be captured. Repeating the whole pipeline with human metabolic network genes led to results confirming the positive contribution of gene pathogenicity information and enabled a more detailed identification of altered metabolic pathways in AD.

Association between thyroid hormones and cognitive functioning in euthyroid elderly adults: a cross-sectional preliminary study from the NHANES 2011-2012 survey

Objective

Changes in serum thyroid hormone levels may affect cognitive functioning in euthyroid individuals. This study used representative data from the National Health and Nutrition Examination Survey (NHANES) to comprehensively examine the association of thyroid hormones with different tests of cognitive functioning among US elderly people aged ≥60 years.

Methods

This study was a cross-sectional preliminary study with a total of 734 participants from the NHANES 2011-2012 survey. Thyroid function was measured using competitive binding immune-enzymatic assays, while cognitive functioning was measured using a series of assessments, including the Consortium to Establish a Registry for Alzheimer's Disease-Word Learning (CERAD W-L), Animal Fluency Test, and Digit Symbol Substitution Test (DSST). Weighted multiple linear regression models and binary logistic regression analyses were used to examine the association between thyroid hormone levels and cognitive functioning. All statistical analyses were performed using SPSS version 20.0, and R software.

Results

Weighted multivariable linear regression showed that FT3 was negatively associated with the Animal Fluency Test and DSST (β=-0.113, 95% CI: -3.279, -0.803, P=0.001; β=-0.062, 95% CI: -6.565, -0.470, P=0.024, respectively) after adjustment for potential covariates. subgroup analysis stratified by sex revealed a negative association between FT3 levels and the Animal Fluency Test in men (β=-0.163, 95% CI: -4.643, -1.153, P=0.001). For female participants, FT3 was negatively associated with not only the Animal Fluency Test but also DSST (β=-0.099, 95% CI: -3.543, -0.093, P=0.039; β=-0.093, 95% CI: -10.288, -1.326, P=0.011). Binary logistic regression showed that the significantly increased adjusted odds ratios (aORs) (95% CI) between the risk of impaired cognitive functioning and FT3 across Q3 and Q4 compared with Q1 were 2.025 (1.092, 3.753) and 2.365 (1.261, 4.433), respectively, for DSST in overall participants. Furthermore, there were significant differences between participants with and without impaired cognitive functioning for serum FT3 levels in overall participants based on DSST score (P=0.020).

Conclusions

There was a significant inverse relationship between FT3 levels within the normal range and cognitive functioning after adjusting for potential covariates. Future longitudinal cohort studies should be conducted to determine the causal relationship between thyroid hormone levels and cognitive functioning.

Hyperthyroidism, hypothyroidism, thyroid stimulating hormone, and dementia risk: results from the NHANES 2011-2012 and Mendelian randomization analysis

Introduction

As the world ages, dementia places a heavy burden on society and the economy, but current methods of diagnosing dementia are still limited and there are no better therapies that target the causes of dementia. The purpose of this work is to explore the relationship between thyroid disease, thyroid stimulating hormone (TSH) concentrations, free tetraiodothyronine (FT4) concentrations and cognitive function.

Methods

This study utilized cognitive function and thyroid data from the 2011-2012 National Health and Nutrition Examination Survey (NHANES) to assess the relationship between different groups of TSH and FT4 concentrations and cognitive function using weighted logistic regression and restricted cubic spline (RCS), and then used two-sample Mendelian Randomization (MR) to assess the causal relationship between hyperthyroidism, hypothyroidism, TSH and FT4 concentrations with dementia.

Results

Our analysis of the 2011-2012 NHANES data showed that the individuals with low TSH concentrations had higher Alzheimer's Disease Word List Registry Consortium1 (CERAD1) and CERAD.delay.recall scores than individuals with high TSH concentrations, and individuals with low FT4 concentrations had higher CERAD3 and Animal Fluency Test scores than individuals with high FT4 concentrations. Our results also showed a non-linear relationship between serum TSH and FT4 concentrations and the Animal Fluency Test. The TSH concentrations within the range of 1.703 to 3.145 mIU/L exhibit a positive correlation with Animal Fluency Test, whereas concentrations outside this range are negatively correlated with Animal Fluency Test. The FT4 concentrations exhibited a positive correlation with Animal Fluency Test to the left of the FT4 concentrations inflection point (0.849 ng/L), whereas to the right of this inflection point, correlation was negative. MR analysis results further indicate that genetic predisposition to hyperthyroidism may be associated with a reduced risk of dementia and vascular dementia(VaD). Conversely, genetic predisposition to hypothyroidism appears to be linked with an increased risk of dementia and VaD. Additionally, genetic predisposition to elevated TSH concentrations may be correlated with a heightened risk of risk of Alzheimer's disease (AD).

Conclusion

This study provides evidence of a nonlinear relationship between TSH and FT4 concentrations and cognitive function, with hyperthyroidism decreasing the risk of dementia and VaD, hypothyroidism increasing the risk of dementia and VaD, and elevated serum TSH concentrations increasing the risk of AD. Furthermore, prioritizing early detection, diagnosis, and treatment through the assessment of thyroid function in individuals at high risk for developing dementia is of paramount importance. This strategy has the potential to significantly contribute to the prevention and deceleration of dementia progression.

Thyroid dysfunction and risk of different types of dementia: A systematic review and meta-analysis

BACKGROUND

The impact of thyroid function on the risk of various types of dementia, including Alzheimer's disease (AD) and vascular dementia (VD), remains unclear. This meta-analysis investigates the association between thyroid dysfunction and the risk of these dementia types, aiming to inform strategies for dementia prevention.

METHODS

A comprehensive search was conducted in PubMed, Embase, and the Cochrane Library for studies published up to February 2023, focusing on the risk of thyroid dysfunction in dementia. We excluded duplicates, studies without full text, those with incomplete data, animal studies, case reports, and reviews. Data analysis was performed using STATA 15.1 software.

RESULTS

Our analysis indicated that overt hyperthyroidism significantly increases the risk of all studied dementia types (OR = 1.18, 95% CI: 1.04-1.35). In contrast, overt hypothyroidism was associated with a decreased risk of AD (OR = 0.73, 95% CI: 0.55-0.98) and VD (OR = 0.71, 95% CI: 0.62-0.82). Subclinical hyperthyroidism also showed a significant association with an increased risk of any dementia (OR = 1.26, 95% CI: 1.09-1.46) and specifically VD (OR = 6.70; 95% CI: 1.38-32.58).

CONCLUSION

This study suggests that overt hypothyroidism may reduce the risk of dementia, including AD and VD, whereas overt and subclinical hyperthyroidism are linked to an increased risk. These findings highlight the importance of monitoring thyroid function as a preventative measure against dementia.

Thyroid function variations within the reference range and cognitive function: A two-sample Mendelian randomization study

BACKGROUND

The causal relationship between thyroid function variations within the reference range and cognitive function remains unknown. We aimed to explore this causal relationship using a Mendelian randomization (MR) approach.

METHODS

Summary statistics of a thyroid function genome-wide association study (GWAS) were obtained from the ThyroidOmics consortium, including reference range thyroid stimulating hormone (TSH) (N = 54,288) and reference range free thyroxine (FT4) (N = 49,269). GWAS summary statistics on cognitive function were obtained from the Social Science Genetic Association Consortium (SSGAC) and the UK Biobank, including cognitive performance (N = 257,841), prospective memory (N = 152,605), reaction time (N = 459,523), and fluid intelligence (N = 149,051). The primary method used was inverse-variance weighted (IVW), supplemented with weighted median, Mr-Egger regression, and MR-Pleiotropy Residual Sum and Outlier. Several sensitivity analyses were conducted to identify heterogeneity and pleiotropy.

RESULTS

An increase in genetically associated TSH within the reference range was suggestively associated with a decline in cognitive performance (β = -0.019; 95%CI: -0.034 to -0.003; P = 0.017) and significantly associated with longer reaction time (β = 0.016; 95 % CI: 0.005 to 0.027; P = 0.004). Genetically associated FT4 levels within the reference range had a significant negative relationship with reaction time (β = -0.030; 95%CI:-0.044 to -0.015; P = 4.85 × 10-5). These findings remained robust in the sensitivity analyses.

CONCLUSIONS

Low thyroid function within the reference range may have a negative effect on cognitive function, but further research is needed to fully understand the nature of this relationship.

LIMITATIONS

This study only used GWAS data from individuals of European descent, so the findings may not apply to other ethnic groups.

Association of Biochemical Parameters and Screening for Mutations in the MCU Gene in Alzheimer's Disease Patients

The most prevalent form of dementia, Alzheimer's disease (AD) is a chronic illness that is on the rise among the geriatric population. Even though research into its biochemical, genetic, and cytogenetic pathways has advanced, its aetiology is still unclear and complex. In this study, we recruited sixty-eight participants diagnosed with AD where the cytogenetic, biochemical parameters and genetic mutations were analysed. Our results revealed chromosomal aberrations such as aneuploidies in the peripheral blood of Alzheimer's disease patients. Biochemical parameters revealed no statistical significance in the study though a pattern could be observed in the serum levels. Further few novel mutations at the c.21 C > T, c.56G > A were observed in the MCU gene of mitochondrial calcium uniporter. All these findings reveal the need for a larger cohort study to gain a better and more detailed understanding of the aetiology of Alzheimer's disease.

Sex and Sleep Disruption as Contributing Factors in Alzheimer's Disease

Alzheimer's disease (AD) affects more women than men, with women throughout the menopausal transition potentially being the most under researched and at-risk group. Sleep disruptions, which are an established risk factor for AD, increase in prevalence with normal aging and are exacerbated in women during menopause. Sex differences showing more disrupted sleep patterns and increased AD pathology in women and female animal models have been established in literature, with much emphasis placed on loss of circulating gonadal hormones with age. Interestingly, increases in gonadotropins such as follicle stimulating hormone are emerging to be a major contributor to AD pathogenesis and may also play a role in sleep disruption, perhaps in combination with other lesser studied hormones. Several sleep influencing regions of the brain appear to be affected early in AD progression and some may exhibit sexual dimorphisms that may contribute to increased sleep disruptions in women with age. Additionally, some of the most common sleep disorders, as well as multiple health conditions that impair sleep quality, are more prevalent and more severe in women. These conditions are often comorbid with AD and have bi-directional relationships that contribute synergistically to cognitive decline and neuropathology. The association during aging of increased sleep disruption and sleep disorders, dramatic hormonal changes during and after menopause, and increased AD pathology may be interacting and contributing factors that lead to the increased number of women living with AD.

Association of Thyroid Hormone Medication Adherence With Risk of Dementia

CONTEXT

Recent studies suggest that hypothyroidism is a risk factor for dementia. Based on existing literature, it is unclear if treatment or compliance to treatment is associated with decreased dementia risk in hypothyroidism patients.

OBJECTIVE

To determine the association between thyroid hormone medication adherence and risk of dementia.

METHODS

A population-based cohort study following patients with newly diagnosed hypothyroidism until incidence of dementia, death, or December 31, 2020, whichever came earliest. The study comprised 41 554 older adults age 50 and above with newly diagnosed hypothyroidism between 2004 and 2008 who underwent health screening. Risk of dementia was evaluated using multivariable-adjusted Cox proportional hazards regression.

RESULTS

Among 5188 men (12.5%) and 36 366 (87.5%) women, 2120 cases of incident dementia were identified. After stratification of the participants according to the interquartile range of the medication possession ratio (MPR), the fourth quartile (highest adherence) showed a 14% lower risk of overall dementia compared with the first quartile (lowest adherence) (adjusted hazard ratio 0.86; 95% CI 0.76-0.97). No consistent association was observed between thyroid hormone medication adherence and vascular dementia. After a dichotomous stratification of the MPR, higher MPR (≥0.8) showed a lower risk of Alzheimer disease (adjusted hazard ratio 0.91; 95% CI 0.84-0.99) than lower MPR (<0.8).

CONCLUSION

Better adherence to thyroid hormone medication may be beneficial in preventing incident dementia, especially Alzheimer disease, in older adults with newly diagnosed hypothyroidism. Along with the resolution of hypothyroid symptoms and the reduction of cardiovascular risk factors, the reduction of dementia risk may be another potential benefit of thyroid hormone medication.

Long-term risk of cardiovascular disease after traumatic brain injury: screening and prevention

Traumatic brain injury (TBI) is highly prevalent among individuals participating in contact sports, military personnel, and in the general population. Although it is well known that brain injury can cause neurological and psychiatric complications, evidence from studies on individuals exposed to a single or repetitive brain injuries suggests an understudied association between TBI and the risk of developing chronic cardiovascular diseases and risk factors for cardiovascular disease. Several studies have shown that people without pre-existing comorbidities who sustain a TBI have a significantly higher risk of developing chronic cardiovascular disease, than people without TBI. Similar observations made in military and professional American-style football cohorts suggest causal pathways through which modifiable cardiovascular risk factors might mediate the relationship between brain injury and chronic neurological diseases. A better understanding of cardiovascular disease risk after TBI combined with a proactive, targeted screening programme might mitigate long-term morbidity and mortality in individuals with TBI, and improve their quality of life.

Impaired Sensitivity to Thyroid Hormones is Associated with Mild Cognitive Impairment in Euthyroid Patients with Type 2 Diabetes

Purpose

The prevalence of mild cognitive impairment (MCI) in patients with type 2 diabetes (T2D) is rapidly increasing. Thyroid hormones are key regulators of cognitive function in adults. The purpose of this study was to investigate the relationship between thyroid hormone sensitivity and MCI in euthyroid T2D patients.

Patients and Methods

A total of 400 euthyroid T2D patients were enrolled in this cross-sectional study, including 218 patients with normal cognition and 182 MCI patients. The Montreal Cognitive Assessment (MoCA) was used to evaluate cognitive function. The free triiodothyronine to free thyroxine (FT3/FT4) ratio was calculated as a measure of peripheral sensitivity to thyroid hormones; the thyroid-stimulating hormone index (TSHI), thyrotrophic thyroxine resistance index (TT4RI) and thyroid feedback quantile-based index (TFQI) were calculated as measures of central sensitivity to thyroid hormones. Linear regression analysis and logistic regression analysis were performed to explore the relationships between these indices of thyroid hormone sensitivity and the MoCA score and MCI, respectively.

Results

Compared with the normal cognitive function group, patients in the MCI group had higher TSHI, TT4RI and TFQI but a lower FT3/FT4 ratio (P<0.05). The MoCA score was positively correlated with the FT3/FT4 ratio but negatively correlated with TSHI, TT4RI and TFQI (P< 0.05). Multivariate logistic regression analysis showed that a low FT3/FT4 ratio and high TSHI, TT4RI and TFQI were independently associated with MCI (P<0.05). After adjustment for confounding factors, the odds ratio (OR) for the association between MCI and the highest tertile of the FT3/FT4 was 0.455 (95% CI: 0.264-0.785), for the highest tertile of TSHI, the OR was 2.380 (95% CI: 1.376-4.119), for the highest tertile of TT4RI, the OR was 2.342 (95% CI:1.353-4.054), and for the highest tertile of TFQI, the OR was 2.536 (95% CI: 1.466-4.387) (P< 0.05).

Conclusion

Impaired sensitivity to thyroid hormones is associated with MCI in euthyroid T2D patients.

Aging under endocrine hormone regulation

Aging is a biological process in which the environment interacts with the body to cause a progressive decline in effective physiological function. Aging in the human body can lead to a dysfunction of the vital organ systems, resulting in the onset of age-related diseases, such as neurodegenerative and cardiovascular diseases, which can seriously affect an individual's quality of life. The endocrine system acts on specific targets through hormones and related major functional factors in its pathways, which play biological roles in coordinating cellular interactions, metabolism, growth, and aging. Aging is the result of a combination of many pathological, physiological, and psychological processes, among which the endocrine system can achieve a bidirectional effect on the aging process by regulating the hormone levels in the body. In this paper, we explored the mechanisms of growth hormone, thyroid hormone, and estrogen in the aging process to provide a reference for the exploration of endocrine mechanisms related to aging.