Plasma sex hormone-binding globulin predicts neurodegeneration and clinical progression in prodromal Alzheimer's disease

Testosterone Supplementation: A Potential Therapeutic Strategy for Amyotrophic Lateral Sclerosis

Objectives: Amyotrophic lateral sclerosis (ALS) is a progressive and fatal disease characterized by the degeneration of spinal cord and brain neurons. Proteomics combined with Mendelian randomization (MR) is an effective method for finding disease treatment targets. Methods: We aimed to seek new therapeutic targets for ALS. A large-scale GWAS on proteomics (4907 circulatory protein) with 35,559 individuals was included as the exposure data; a GWAS with 138,086 ALS patients was used as the outcome data; we found that a high level of sex hormone-binding globulin (SHBG) is a risk factor by MR analysis. Colocalization analyses were used to validate the causality between SHBG and ALS further. Functional enrichment found a high level of SHBG was associated with a low level of bioavailable testosterone. Two-sample MR confirmed the association of SHBG (400,210 samples), bioavailable testosterone (367,289 samples), and ALS. Results: A high level of SHBG, and a low level of bioavailable testosterone are risk factors for ALS. Conclusions: A low level of bioavailable testosterone is a risk factor for ALS. Although our study is relatively limited and cannot fully confirm that testosterone supplementation has a therapeutic effect on ALS, it offers a promising direction for ALS therapy.

The Common Alzheimer's Disease Research Ontology (CADRO) for biomarker categorization

Biomarkers are vital to Alzheimer's disease (AD) drug development and clinical trials, and will have an increasing role in clinical care. In this narrative review, we demonstrate the use of the National Institutes on Aging/Alzheimer's Association (NIA/AA) Common Alzheimer's Disease Research Ontology (CADRO) system for the categorization of biomarkers based on the primary mechanism on which they report. We show that biomarkers are available (in various levels of validation) for all CADRO processes. Application of the CADRO system demonstrates gaps in the field where novel biomarkers are needed for specific aspects of the disease, and assays to detect and measure biological changes, in individuals with symptomatic or preclinical AD. We demonstrate the CADRO system as a means of categorizing established and candidate AD biomarkers, showing the feasibility and practicality of the system. CADRO can assist with biomarker selection for AD clinical trials and drug development, and may eventually be applied to implementing biomarkers in patient care.

Highlights

The Common Alzheimer's Disease Research Ontology (CADRO) system can be used to categorize biomarkers for drug development.We demonstrate the use of CADRO with Alzheimer's disease (AD) biomarkers.We identified AD biomarkers in each of the CADRO categories.CADRO can be incorporated into current AD drug development and clinical trial systems.

Causal influences of testosterone on brain structure change rate: A sex-stratified Mendelian randomization study

The impact of testosterone levels on changes in brain structure has been reported. However, it is still unclear which specific brain region could be affected. This study approached Mendelian randomization method to reveal the causal relationship between testosterone levels and the rate of longitudinal structural changes in the brain. The testosterone-related GWAS data were determined from 425,097 European participants. The GWAS data on the rate of longitudinal structural changes in the brain came from the ENIGMA consortium, which included 15,640 all-age participants from 40 longitudinal cohorts. The inverse variance weighted was considered as the main estimate, MR Egger and weighted median methods were used to supplement IVW. A positive correlation was found between total testosterone levels and bioavailable testosterone levels in women and age-independent longitudinal changes in cerebral WM and surface area. The sex hormone-binding globulin levels were found a negative correlation with age-dependent longitudinal structural changes of cortical GM in men. Additionally, we also found that the bioavailable testosterone level in males was negatively associated with the quadratic age-dependent longitudinal change rate in the globus pallidum. We also found estradiol levels and sex hormone-binding globulin levels were negatively associated with the quadratic age-dependent longitudinal change rate of total brain in men. Moreover, we found a positive correlation between total testosterone levels and linear age-dependent longitudinal changes in the hippocampus in both males and females. The testosterone levels in different genders may have varying degrees of causal effects on the structural changes of brain regions. These findings provide evidence for the influence of the brain glandular axis on brain structure, particularly during female brain development.

Correlations of cognitive function with serum levels of homocysteine, sex hormone binding globulin, and leptin in patients with schizophrenia

Objective

To investigate the correlations of cognitive function with serum levels of homocysteine (Hcy), sex hormone binding globulin (SHBG), and leptin in patients with schizophrenia.

Methods

This was retrospective study. This study included 58 patients with schizophrenia (SCZ) as observation group and 60 clinically healthy individuals as control group admitted to Xiangshan County Hospital of Traditional Chinese Medicine Medical and Health Group Third Hospital from March 2022 to June 2023. Serum levels of Hcy, SHBG, and leptin in the two groups were measured, and Pearson correlation analysis was conducted to investigate the correlations between the Hcy, SHBG, and leptin levels and the psychiatric symptoms and cognitive function in the observation group.

Results

The Hcy and SHBG levels in the observation group were significantly higher than those in the control group (p<0.05, respectively), and the leptin level was lower than that in the control group (p<0.05). The observation group scored significantly lower than the control group for each dimension of the MCCB (p<0.05, respectively). In the observation group, Hcy was positively correlated with negative symptoms and the PANSS total score (p<0.05, respectively) and was negatively correlated with scores for the leptin was negatively correlated with negative symptoms and the PANSS total score (p<0.05, respectively) and was positively correlated with scores for speed of processing (SOP), WMS-III, BVMT, and MSCEIT (p<0.05, respectively).

Conclusions

Increased levels of Hcy and SHBG and decreased leptin are strongly associated with the occurrence of cognitive impairment in SCZ cases. Therefore, clinical observation and monitoring of these markers can help identify changes in patient conditions.

Investigating the Genetic Association of 40 Biochemical Indicators with Parkinson's Disease

The mechanisms of Parkinson's disease (PD) are not fully understood, which hinders the development of effective therapies. Research indicates that lower levels of biochemical indicators like bilirubin, vitamin D, and cholesterol may elevate the risk of PD. However, clinical studies on abnormal levels of biochemical indicators in PD patients' circulation are inconsistent, leading to ongoing debate about their association with PD. Here, we investigate the genetic correlation between 40 biochemical indicators and PD using a bidirectional two-sample Mendelian randomization (MR) approach to uncover potential causal relationships. Data from genome-wide association studies (GWAS) were utilized, with genetic variations from specific lineages serving as instrumental variables (IVs). The methodology followed the STROBE-MR checklist and adhered to the three principal assumptions of MR. Statistical analyses employed methods including inverse variance weighting (IVW), MR-Egger, weighted median, and weighted mode. Biochemical indicators including albumin, C-reactive protein (CRP), and sex hormone-binding globulin (SHBG) showed significant associations with PD risk. Elevated levels of albumin (OR = 1.246, 95% CI 1.006-1.542, P = 0.043) and SHBG (OR = 1.239, 95% CI 1.065-1.439, P = 0.005) were linked to higher PD risk. Conversely, increased CRP levels (OR = 0.663, 95% CI 0.517-0.851; P = 0.001) could potentially lower PD risk. The robustness of the results was confirmed through various MR analysis techniques, including assessments of directional pleiotropy and heterogeneity using MR-Egger intercept and MR-PRESSO methods. This study systematically reveals, for the first time at the genetic level, the relationship between 40 biochemical indicators and PD risk. Our research verifies the role of inflammation in PD and provides new genetic evidence, further advancing the understanding of PD pathogenesis. The study shows a positive correlation between albumin and SHBG with PD risk and a negative correlation between CRP and PD risk. This study identifies for the first time that SHBG may be involved in the onset of PD and potentially worsen disease progression.

Longitudinal analysis of host protein serum signatures of treatment and recovery in pulmonary tuberculosis

BACKGROUND

A better understanding of treatment progression and recovery in pulmonary tuberculosis (TB) infectious disease is crucial. This study analyzed longitudinal serum samples from pulmonary TB patients undergoing interventional treatment to identify surrogate markers for TB-related outcomes.

METHODS

Serum that was collected at baseline and 8, 17, 26, and 52 weeks from 30 TB patients experiencing durable cure were evaluated and compared using a sensitive LC-MS/MS proteomic platform for the detection and quantification of differential host protein signatures relative to timepoint. The global proteome signature was analyzed for statistical differences across the time course and between disease severity and treatment groups.

RESULTS

A total of 676 proteins showed differential expression in the serum over these timepoints relative to baseline. Comparisons to understand serum protein dynamics at 8 weeks, treatment endpoints at 17 and 26 weeks, and post-treatment at 52 weeks were performed. The largest protein abundance changes were observed at 8 weeks as the initial effects of antibiotic treatment strongly impacted inflammatory and immune modulated responses. However, the largest number of proteome changes was observed at the end of treatment time points 17 and 26 weeks respectively. Post-treatment 52-week results showed an abatement of differential proteome signatures from end of treatment, though interestingly those proteins uniquely significant at post-treatment were almost exclusively downregulated. Patients were additionally stratified based upon disease severity and compared across all timepoints, identifying 461 discriminating proteome signatures. These proteome signatures collapsed into discrete expression profiles with distinct pathways across immune activation and signaling, hemostasis, and metabolism annotations. Insulin-like growth factor (IGF) and Integrin signaling maintained a severity signature through 52 weeks, implying an intrinsic disease severity signature well into the post-treatment timeframe.

CONCLUSION

Previous proteome studies have primarily focused on the 8-week timepoint in relation to culture conversion status. While this study confirms previous observations, it also highlights some differences. The inclusion of additional end of treatment and post-treatment time points offers a more comprehensive assessment of treatment progression within the serum proteome. Examining the expression dynamics at these later time periods will help in the investigation of relapse patients and has provided indicative markers of response and recovery.

Correlations between SHBG, Sex Hormones, Inflammation, and Neurocognitive Decline in Alzheimer's Disease: A Retrospective Study

BACKGROUND

Alzheimer's Disease (AD) is characterized by a progressive neurodegenerative process leading to cognitive decline and functional impairment. Endocrine factors, particularly sex hormones and their binding proteins, play a critical role in AD pathophysiology. Understanding the relationship between these factors and AD is essential for developing targeted interventions.

OBJECTIVE

To investigate the potential links between sex hormone binding globulin (SHBG) levels, sex hormone profiles, inflammatory markers, and neurocognitive decline in patients with AD.

METHODS

A retrospective case-control investigation was conducted with 110 AD patients who were admitted to our hospital from January 2021 to December 2023, and the patients were classified into either a mild neurocognitive impairment group (n=59) or a moderate to severe neurocognitive impairment group (n=51) according to their cognitive function. Correlation and regression analyses were conducted to examine relationships between variable factors.

RESULTS

The study revealed a significant neurocognitive decline in AD patients with lower Mini-- Mental State Examination (MMSE) and higher AD Assessment Scale-Cognitive Subscale (ADAS- Cog) scores in the moderate to severe neurocognitive impairment group compared to the mild neurocognitive impairment group. Additionally, the moderate to severe neurocognitive impairment group significantly increased for SHBG, estradiol, progesterone inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β)). It decreased for follicle-stimulating hormone (FSH) and luteinizing hormone (LH)]. Moreover, significant positive correlations were found between SHBG levels and ADAS-Cog scores, and significant negative correlations were found between SHBG levels and MMSE scores. FSH showed significant negative correlations with the MMSE score, while certain inflammatory markers demonstrated significant correlations with neurocognitive abilities. The correlation between sex hormones and inflammatory factors is weak. FSH, LH, SHBG, CRP, IL-6, TNF-α, and IL-1β are risk factors for neurocognitive impairment, while E2 and P are protective factors.

CONCLUSION

The study provides evidence of significant correlations between SHBG levels, sex hormone profiles, inflammatory markers, and neurocognitive decline in AD patients.

Neonatal Maternal Separation Induces Sexual Dimorphism in Brain Development: The Influence on Amino Acid Levels and Cognitive Disorders

Repeated maternal separation (MS) is a useful experimental model in rodents for studying the long-term influence of early-life stress on brain neurophysiology. In our work, we assessed the effect of repeated MS (postnatal day (PND)1-21, 180 min/day) on the postnatal development of rat brain regions involved in memory using proton magnetic resonance spectroscopy (1HMRS) for tissue volume and the level of amino acids such as glutamate, aspartate, glutamine, glycine and gamma-aminobutyric acid (GABA) in the hippocampus. We assessed whether these effects are sex dependent. We also use novel object recognition (NOR) task to examine the effect of MS on memory and the effect of ethanol on it. Finally, we attempted to ameliorate postnatal stress-induced memory deficits by using VU-29, a positive allosteric modulator (PAM) of the metabotropic glutamate type 5 (mGlu5) receptor. In males, we noted deficits in the levels of glutamate, glycine and glutamine and increases in GABA in the hippocampus. In addition, the values of perirhinal cortex, prefrontal cortex and insular cortex and CA3 were decreased in these animals. MS females, in contrast, demonstrated significant increase in glutamate levels and decrease in GABA levels in the hippocampus. Here, the CA1 values alone were increased. VU-29 administration ameliorated these cognitive deficits. Thus, MS stress disturbs amino acids levels mainly in the hippocampus of adult male rats, and enhancement of glutamate neurotransmission reversed recognition memory deficits in these animals.

Sex Hormone-Binding Globulin and Risk of Incident Dementia in Middle-Aged to Older Women: Results from the UK Biobank Cohort Study

INTRODUCTION

The association of serum sex hormone-binding globulin (SHBG) concentrations with dementia risk remains uncertain in middle-aged to older women. We examined associations of serum SHBG levels with incidence of all-cause dementia and its subtypes in middle-aged to older women from the large population-based UK Biobank cohort study.

METHODS

Serum total SHBG levels were measured by immunoassay. The incidence of all-cause dementia and its subtypes was recorded. Cox proportional hazards models were used to calculate hazard ratios (HR) for main outcomes.

RESULTS

Among 171,482 community-dwelling women (mean [SD] age was 59.9 [5.4] years, median follow-up of 11.8 years), 2,368 developed dementia, including 1,088 from Alzheimer's disease (AD), 451 from vascular dementia (VAD), and 1,609 from other dementia. After multivariable adjustments, higher serum SHBG levels were significantly associated with higher risks of all-cause dementia, AD, and other dementia (all p < 0.05). Compared to those in the lowest quartile of SHBG levels, participants in the highest quartile of SHBG levels had a higher risk of all-cause dementia (HR: 1.34; 95% confidence interval [CI]: 1.16-1.53), AD (HR: 1.32; 95% CI: 1.07-1.62), and other dementia (HR: 1.44; 95% CI: 1.21-1.70). However, this relationship was not significant for VAD (HR: 1.16; 95% CI: 0.86-1.56).

CONCLUSION

These findings indicated that higher serum SHBG concentrations were independently associated with higher risks of incident all-cause dementia, as well as AD and other dementia among middle-aged to older women. No association was found for VAD.

The Role of Steroidomics in the Diagnosis of Alzheimer's Disease and Type 2 Diabetes Mellitus

Epidemiological studies suggest an association between Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM). This study aimed to investigate the pathophysiological markers of AD vs. T2DM for each sex separately and propose models that would distinguish control, AD, T2DM, and AD-T2DM comorbidity groups. AD and T2DM differed in levels of some circulating steroids (measured mostly by GC-MS) and in other observed characteristics, such as markers of obesity, glucose metabolism, and liver function tests. Regarding steroid metabolism, AD patients (both sexes) had significantly higher sex hormone binding globulin (SHBG), cortisol, and 17-hydroxy progesterone, and lower estradiol and 5α-androstane-3α,17β-diol, compared to T2DM patients. However, compared to healthy controls, changes in the steroid spectrum (especially increases in levels of steroids from the C21 group, including their 5α/β-reduced forms, androstenedione, etc.) were similar in patients with AD and patients with T2DM, though more expressed in diabetics. It can be assumed that many of these steroids are involved in counter-regulatory protective mechanisms that mitigate the development and progression of AD and T2DM. In conclusion, our results demonstrated the ability to effectively differentiate AD, T2DM, and controls in both men and women, distinguish the two pathologies from each other, and differentiate patients with AD and T2DM comorbidities.

The association between sex hormones and the change in brain-predicted age difference in older women

OBJECTIVE

The role of circulating sex hormones on structural brain ageing is yet to be established. This study explored whether concentrations of circulating sex hormones in older women are associated with the baseline and longitudinal changes in structural brain ageing, defined by the brain-predicted age difference (brain-PAD).

DESIGN

Prospective cohort study using data from NEURO and Sex Hormones in Older Women; substudies of the ASPirin in Reducing Events in the Elderly clinical trial.

PATIENTS

Community-dwelling older women (aged 70+ years).

MEASUREMENTS

Oestrone, testosterone, dehydroepiandrosterone (DHEA), and sex-hormone binding globulin (SHBG) were quantified from plasma samples collected at baseline. T1-weighted magnetic resonance imaging was performed at baseline, 1 and 3 years. Brain age was derived from whole brain volume using a validated algorithm.

RESULTS

The sample comprised of 207 women not taking medications known to influence sex hormone concentrations. A statistically higher baseline brain-PAD (older brain age relative to chronological age) was seen for women in the highest DHEA tertile compared with the lowest in the unadjusted analysis (p = .04). This was not significant when adjusted for chronological age, and potential confounding health and behavioural factors. Oestrone, testosterone and SHBG were not associated with brain-PAD cross-sectionally, nor were any of the examined sex hormones or SHBG associated with brain-PAD longitudinally.

CONCLUSION

No strong evidence of an association between circulating sex hormones and brain-PAD. Given there is prior evidence to suggests sex hormones may be important for brain ageing, further studies of circulating sex hormones and brain health in postmenopausal women are warranted.

Sex hormones, SHBG and cognitive performance among older Australian women: an observational study

OBJECTIVE

This study aims to explore the associations between sex hormones and cognitive performance in older women.

METHODS

Associations between sex hormones, sex hormone binding globulin (SHBG) and cognitive performance were examined in women aged at least 70 years, without dementia and not using medications that influence sex hormones. Linear and generalized linear regression models included age, body mass index, education, smoking, alcohol, living circumstances, diabetes, hypertension, depression and impaired renal function.

RESULTS

The included 5511 women had a median (interquartile range) age of 73.9 (71.6-77.6) years. No associations were found for estrone, estradiol, testosterone or dehydroepiandrosterone and cognitive performance. SHBG concentrations above quartile 1 (Q1) were significantly inversely associated with processing speed (Q2, β = -0.94, 95% confidence interval [CI] - 1.64 to -0.24, p = 0.009; Q3, β = -0.82, 95% CI -1.53 to -0.10, p = 0.025; and Q4, β = -0.95, 95% CI -1.70 to -0.20, p = 0.013).

CONCLUSIONS

Sex hormones were not associated with cognitive performance. The finding that low SHBG is associated with better processing speed warrants further investigation. The null findings for the sex hormones establish a firm baseline to confidently explore the association between sex hormones and longitudinal cognitive performance in this population.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number Register (ISRCTN83772183) and ClinicalTrials.gov (NCT01038583).

Causal effects of serum sex hormone binding protein levels on the risk of amyotrophic lateral sclerosis: a mendelian randomization study

Background

Extensive observational studies have suggested an association between serum sex-hormone binding globulin (SHBG) and Alzheimer's disease (AD); however, causality remains unclear. Furthermore, the effects on other neurodegenerative diseases have been poorly investigated. We aimed to explore the causal effects of genetically predicted SHBG serum levels on common neurodegenerative diseases.

Methods

A two-sample Mendelian randomization (MR) approach was used. Genetic variants of SHBG levels in the serum, detected using the chemiluminescent two-step sandwich immunoassay method, were identified from a genome-wide association meta-analysis from the UK Biobank (N=363,228). Summary-level data for AD, and other common neurodegenerative diseases including Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD) were adopted from the corresponding large genome-wide association studies of individuals of European ancestry, which were either clinically or autopsy-diagnosed. Causal estimates were calculated using the inverse-variance weighted (IVW) method and several sensitivity methods (MR-Egger, weighted median, and weighted mode). Egger intercept, MR-PRESSO, and leave-one-out analyses were used to identify potential violations.

Results

Genetically determined serum SHBG levels [odds ratio (ORIVW) =1.113, 95% CI: 1.019-1.215, P=0.017] were associated with an increased risk of ALS. This causal effect was confirmed using sensitivity analyses, including the MR-Egger (OR =1.229, 95% CI: 1.049-1.441, P=0.012), weighted median (OR =1.231, 95% CI: 1.077-1.406, P=0.002), and weighted mode (OR =1.235, 95% CI: 1.067-1.431, P=0.005) methods. No notable heterogeneity or directional pleiotropy was observed. However, leave-one-out analysis showed that rs9892297 drove the observed effects. There was no evidence that genetically predicted serum SHBG levels affect other neurodegenerative diseases, including AD, PD, MS, DLB, and FTD (all P>0.05).

Conclusions

This MR analysis found that genetically determined serum SHBG was associated with an increased risk of ALS rather than AD, which is inconsistent with previous observational studies. This novel finding highlights the potential of SHBG in peripheral serum for ALS prevention. Further research into the effects of SHBG on other neurodegenerative diseases is required, especially because of the increased utilization of hormone therapy.

Cognition and mental health in menopause: A review

Cognitive and mood changes are frequently mentioned as complaints before, during and after menopausal transition. There is substantial biological evidence for such associations to occur, as there are many mechanisms through which oestrogens can affect the brain: by regulating metabolism, increasing cerebral blood flow and dendritic outgrowth, by acting on nerve growth factors through the co-localisation of receptors via neurotransmitter synthesis and turnover and many more. However, the evidence for objective and longer-term changes in cognitive function and mental health over the menopausal transition and beyond is less clear. While hormone treatment (HT) including oestrogens could potentially reverse these psychological issues, the evidence of long-term benefit is also inconclusive. However, for women with severe menopausal complaints, and particularly for those who undergo early menopause, including women with premature ovarian insufficiency, personalised HT at least up to the natural age of menopause around 50 should be considered, which is probably safe up to 10 years of treatment, unless contraindicated. This paper reviews the evidence for changes in psychological health related to menopausal transition and HTs.

Sex Hormone-Binding Globulin (SHBG) in Cerebrospinal Fluid Does Not Discriminate between the Main FTLD Pathological Subtypes but Correlates with Cognitive Decline in FTLD Tauopathies

Biomarkers to discriminate the main pathologies underlying frontotemporal lobar degeneration (FTLD-Tau, FTLD-TDP) are lacking. Our previous FTLD cerebrospinal fluid (CSF) proteome study revealed that sex hormone-binding globulin (SHBG) was specifically increased in FTLD-Tau patients. Here we investigated the potential of CSF SHBG as a novel biomarker discriminating the main FTLD pathological subtypes. SHBG was measured in CSF samples from patients with FTLD-Tau (n = 23), FTLD-TDP (n = 29) and controls (n = 33) using an automated electro-chemiluminescent immunoassay. Differences in CSF SHBG levels across groups, as well as its association with CSF YKL40, pTau181/total-Tau ratio and cognitive function were analyzed. CSF SHBG did not differ across groups, though a trend towards elevated levels in FTLD-Tau cases compared to FTLD-TDP and controls was observed. CSF SHBG levels were not associated with either CSF YKL40 or the p/tTau ratio. They, however, inversely correlated with the MMSE score (r = -0.307, p = 0.011), an association likely driven by the FTLD-Tau group (r FTLD-Tau = -0.38; r FTLD-TDP = -0.02). CSF SHBG is not a suitable biomarker to discriminate FTLD-Tau from FTLD-TDP.

Blood-based biomarkers in hypothalamic-pituitary axes for the risk of dementia or cognitive decline: a systematic review and meta-analysis

Blood-based biomarkers are ideal candidates for dementia prediction. This systematic review and meta-analysis aimed to evaluate longitudinal relationships of blood hormones and hormone-binding proteins in hypothalamic-pituitary (HP) axes with dementia or cognitive decline. PubMed, MEDLINE, EMBASE, PsycINFO, and BIOSIS were systematically searched from 1919 to June 2020. Fifteen types of hormones and four types of hormone-binding proteins were measured in 48 prospective studies. Increased risk of dementia or cognitive decline could be predicted by elevated blood concentrations of free-thyroxine (free-T4, RR = 1.06, p = 0.001) and sex hormone-binding globulin (SHBG, RR = 1.10, p = 0.025). Lower thyroid-stimulating hormone (TSH) levels within (RR = 1.28, p < 0.001) and below (RR = 1.27, p = 0.004) the normal range were both risky. Current evidence suggests the alterations of multiple blood molecules in HP axes, especially TSH, free-T4, and SHBG precede the incidence of dementia or cognitive decline. The underpinning etiology remains to be elucidated in the future.