Clinical laboratory tests and five-year incidence of major depressive disorder: a prospective cohort study of 433,890 participants from the UK Biobank

Meta-analyses of epigenetic age acceleration and GrimAge components of schizophrenia or first-episode psychosis

Schizophrenia is a common chronic psychiatric disorder that causes age-related dysfunction. The life expectancy in patients with schizophrenia is ≥10 years shorter than that in the general population because of the higher risk of other diseases, such as cardiovascular diseases. Aging studies based on DNA methylation status have received considerable attention. Several epigenetic age accelerations and predicted values of aging-related proteins (GrimAge and GrimAge2 components) have been analyzed in multiple diseases. However, no studies have investigated up to GrimAge and GrimAge2 components between patients with schizophrenia and controls. Therefore, we aimed to conduct multiple regression analyses to investigate the association between schizophrenia and epigenetic age accelerations and GrimAge and GrimAge2 components in seven cohorts. Furthermore, we included patients with first-episode psychosis whose illness duration was often shorter than schizophrenia in our analysis. We integrated these results with meta-analyses, noting the acceleration of GrimAge, GrimAge2, and DunedinPACE, and increase in adrenomedullin, beta-2 microglobulin, cystatin C, and plasminogen activation inhibitor-1 levels, in patients with schizophrenia or first-episode psychosis. These results corroborated the finding that patients with schizophrenia had an increased risk of diabetes, cardiovascular disease, and cognitive dysfunction from a biological perspective. Patients with schizophrenia and first-episode psychosis showed differences in the results when compared with controls. Such analyses may lead to the development of novel therapeutic targets to patients with schizophrenia or relevant diseases from the perspective of aging in the future.

Sex-specific association of peripheral blood cell indices and inflammatory markers with depressive symptoms in early adolescence

BACKGROUND

Previous studies have reported the correlation of dysregulated blood cell indices and peripheral inflammatory markers with depression in adults but limited studies have examined this correlation in early adolescents.

METHODS

This study used data from the Chinese Early Adolescents Cohort Study, which was conducted in Anhui, China. Students' depression symptoms were repeatedly measured using the Chinese version of the Center for Epidemiological Studies Depression Scale for Children. Students' blood samples were collected in September 2019 and September 2021. The peripheral blood cell counts and inflammatory marker levels were determined using routine blood tests. Multivariable regression models were used to explore the associations between blood cell indices and adolescent depressive symptoms in both the whole sample and the sex-stratified samples.

RESULTS

The white blood cell (WBC) count, neutrophil count (NC), platelet (PLT) count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, and systemic immune inflammation index (SII) were positively correlated with the severity of depressive symptoms during follow-up. The mean corpuscular volume (MCV), mean hemoglobin (HGB) volume (MCH), and mean corpuscular HGB concentration (MCHC) exhibited negative temporal correlations with depressive symptoms. Additionally, several sex-specific blood cell markers were correlated with depression. Male adolescents with increased red blood cell (RBC) and female adolescents with decreased HGB levels and upregulated WBC, NC, NLR, and SII levels exhibited severe depressive symptoms at follow-up.

CONCLUSIONS

These findings suggested the potential usefulness of peripheral blood cell indices in the assessment of depression in early adolescents.

Total testosterone plays a crucial role in the pathway from hypothyroidism to broad depression in women

BACKGROUND

Depression tends to develop in correlation with hypothyroidism, however it's unclear how testosterone traits contribute to this association. We examined the causal association between depression, testosterone traits, and hypothyroidism using Mendelian randomization (MR).

METHOD

We conducted univariable and multivariable MR studies using summary-level statistics from genome-wide association studies (GWAS) of Hypothyroidism (n = 213,990), broad depression (n = 322,580), probable major depressive disorder (probable MDD) (n = 174,519), and International Classification of Diseases (ICD)-9 or ICD-10-coded MDD (n = 217,584) from European ancestry. The inverse variance weighted (IVW) method was used as the main MR analysis.

RESULTS

In univariate MR analysis, there is a positive causal relationship between hypothyroidism and broad depression (P = 0.0074; OR = 1.0066; 95%CI: 1.0018-1.0114) and probable MDD (P = 0.0242; OR = 1.0056; 95%CI: 1.0007-1.0105). In females, there is a causal relationship between hypothyroidism and decreased total testosterone (P < 0.001; OR = 0.9747; 95%CI: 0.9612-0.9885) and sex hormone binding globulin (SHBG) levels (P = 0.0418; OR = 0.9858; 95%CI: 0.9723-0.9995). In females, there is an inverse causal relationship between total testosterone and broad depression (P = 0.0349; OR = 0.9898; 95%CI: 0.9804-0.9993). Furthermore, in multivariate MR analysis, after adjusting for total testosterone in females, hypothyroidism only has a positive causal relationship with probable MDD, and the relationship with broad depression is no longer significant. Most notably, after adjusting for hypothyroidism, the inverse causal effect of female total testosterone levels on broad depression becomes more significant (P = 0.0154; OR = 0.9878; 95%CI: 0.9780-0.9977).

CONCLUSION

Hypothyroidism increases the risk of broad depression and probable MDD development. Total Testosterone appears to play an important role in the relationship between hypothyroidism and broad depression in female.

Peripheral biomarkers to differentiate bipolar depression from major depressive disorder: a real-world retrospective study

BACKGROUND

Bipolar depression (BPD) is often misdiagnosed as a major depressive disorder (MDD) in clinical practice, which may be attributed to a lack of robust biomarkers indicative of differentiated diagnosis. This study analysed the differences in various hormones and inflammatory markers to explore peripheral biomarkers that differentiate BPD from MDD patients.

METHODS

A total of 2,048 BPD and MDD patients were included. A panel of blood tests was performed to determine the levels of sex hormones, stress hormones, and immune-related indicators. Propensity score matching (PSM) was used to control for the effect of potential confounders between two groups and further a receiver operating characteristic (ROC) curve was used to analyse the potential biomarkers for differentiating BPD from MDD.

RESULTS

Compared to patients with MDD, patients with BPD expressed a longer duration of illness, more hospitalisations within five years, and an earlier age of onset, along with fewer comorbid psychotic symptoms. In terms of biochemical parameters, MDD patients presented higher IgA and IgM levels, while BPD patients featured more elevated neutrophil and monocyte counts. ROC analysis suggested that combined biological indicators and clinical features could moderately distinguish between BPD and MDD. In addition, different biological features exist in BPD and MDD patients of different ages and sexes.

CONCLUSIONS

Differential peripheral biological parameters were observed between BPD and MDD, which may be age-sex specific, and a combined diagnostic model that integrates clinical characteristics and biochemical indicators has a moderate accuracy in distinguishing BPD from MDD.

Disturbed sex hormone milieu in males and females with major depressive disorder and low-grade inflammation

Sex hormones have biological effects on inflammation, and these might contribute to the sex-specific features of depression. C-reactive protein (CRP) is the most widely used inflammatory biomarker and consistent evidence shows a significant proportion (20-30 %) of patients with major depressive disorder (MDD) have CRP levels above 3 mg/L, a threshold indicating at least low-grade inflammation. Here, we investigate the interplay between sex hormones and CRP in the cross-sectional, observational Biomarkers in Depression Study. We measured serum high-sensitivity (hs-)CRP, in 64 healthy controls and 178 MDD patients, subdivided into those with hs-CRP below 3 mg/L (low-CRP; 53 males, 72 females) and with hs-CRP above 3 mg/L (high-CRP; 19 males, 34 females). We also measured interleukin-6, testosterone, 17-β-estradiol (E2), progesterone, sex-hormone binding globulin (SHBG), follicle-stimulating and luteinising hormones, and calculated testosterone-to-E2 ratio (T/E2), free androgen and estradiol indexes (FAI, FEI), and testosterone secretion index. In males, high-CRP patients had lower testosterone than controls (p = 0.001), and lower testosterone (p = 0.013), T/E2 (p < 0.001), and higher FEI (p = 0.015) than low-CRP patients. In females, high-CRP patients showed lower SHGB levels than controls (p = 0.033) and low-CRP patients (p = 0.034). The differences in testosterone, T/E2 ratio, and FEI levels in males survived the Benjamini-Hochberg FDR correction. In linear regression analyses, testosterone (β = -1.069 p = 0.033) predicted CRP concentrations (R2 = 0.252 p = 0.002) in male patients, and SHBG predicted CRP levels (β = -0.628 p = 0.009, R2 = 0.172 p = 0.003) in female patients. These findings may guide future research investigating interactions between gonadal and immune systems in depression, and the potential of hormonal therapies in MDD with inflammation.

Irritable Bowel Syndrome Is Associated With Brain Health by Neuroimaging, Behavioral, Biochemical, and Genetic Analyses

BACKGROUND

Irritable bowel syndrome (IBS) interacts with psychopathology in a complex way; however, little is known about the underlying brain, biochemical, and genetic mechanisms.

METHODS

To clarify the phenotypic and genetic associations between IBS and brain health, we performed a comprehensive retrospective cohort study on a large population. Our study included 171,104 participants from the UK Biobank who underwent a thorough assessment of IBS, with the majority also providing neuroimaging, behavioral, biochemical, and genetic information. Multistage linked analyses were conducted, including phenome-wide association analysis, polygenic risk score calculation, and 2-sample Mendelian randomization analysis.

RESULTS

The phenome-wide association analysis showed that IBS was linked to brain health problems, including anxiety and depression, and poor cognitive performance. Significantly lower brain volumes associated with more severe IBS were found in key areas related to emotional regulation and higher-order cognition, including the medial orbitofrontal cortex/ventromedial prefrontal cortex, anterior insula, anterior and mid-cingulate cortices, dorsolateral prefrontal cortex, and hippocampus. Higher triglycerides, lower high-intensity lipoprotein, and lower platelets were also related (p < 1 × 10-10) to more severe IBS. Finally, Mendelian randomization analyses demonstrated potential causal relationships between IBS and brain health and indicated possible mediating effects of dyslipidemia and inflammation.

CONCLUSIONS

For the first time, this study provides a comprehensive understanding of the relationship between IBS and brain health phenotypes, integrating perspectives from neuroimaging, behavioral performance, biochemical factors, and genetics, which is of great significance for clinical applications to potentially address brain health impairments in patients with IBS.

Clinical laboratory tests and dementia incidence: A prospective cohort study

BACKGROUND

Dementia is a major public health issue and a heavy economic burden. It is urgently necessary to understand the underlying biological processes and to identify biomarkers predicting risk of dementia in the preclinical stage for prevention and treatment.

METHODS

By using the data of the 367,093 white British individuals from UK Biobank, we investigated the relationship between 56 laboratory measures and 5-year dementia incidence using logistic regression. Adjusted odds ratios for dementia incidence with values below or above the 95 % confidence interval (<2.5th or > 97.5th percentile) on each of clinical laboratory tests were computed.

RESULTS

We observed that markers of endocrine dysregulation: elevated hemoglobin A1C (AOR = 2.01 [1.35, 2.88]) was associated with increased dementia incidence. Indicators of liver dysfunction: elevated gamma glutamyltransferase (AOR = 2.28 [1.49, 3.32]), and albumin (AOR = 2.01 [1.15, 3.25]), indicators of renal impairment: high urea (AOR = 1.69 [1.15, 2.40]), and cystatin C (AOR = 1.89 [1.30, 2.67]), and some immune markers, like elevated neutrophill count, low lymphocyte count, and indicators of anemia were also observed to be associated with increased dementia incidence. Both low and high concentrations of insulin-like growth factor 1 were found to be risk factors for dementia.

LIMITATIONS

This is an observational study.

CONCLUSION

Several systemic biomarkers were associated with dementia incidence. These results implicate a contributory role of diverse biological processes to dementia onset, and enrich our understanding of potential dementia prevention strategy.

Metabolic Profile and Long-Term Risk of Depression, Anxiety, and Stress-Related Disorders

Importance

Biomarkers of lipid, apolipoprotein, and carbohydrate metabolism have been previously suggested to be associated with the risk for depression, anxiety, and stress-related disorders, but results are inconsistent.

Objective

To examine whether the biomarkers of carbohydrate, lipid, and apolipoprotein metabolism are associated with the risk of depression, anxiety, and stress-related disorders.

Design, Setting, and Participants

This population-based cohort study with longitudinal data collection assessed 211 200 participants from the Apolipoprotein-Related Mortality Risk (AMORIS) cohort who underwent occupational health screening between January 1, 1985, and December 31, 1996, mainly in the Stockholm region in Sweden. Statistical analysis was performed during 2022 to 2023.

Exposures

Lipid, apolipoprotein, and carbohydrate biomarkers measured in blood.

Main Outcomes and Measures

The associations between biomarker levels and the risk of developing depression, anxiety, and stress-related disorders through the end of 2020 were examined using Cox proportional hazards regression models. In addition, nested case-control analyses were conducted within the cohort, including all incident cases of depression, anxiety, and stress-related disorders, and up to 10 control individuals per case who were individually matched to the case by year of birth, sex, and year of enrollment to the AMORIS cohort, using incidence density sampling. Population trajectories were used to illustrate the temporal trends in biomarker levels for cases and controls.

Results

A total of 211 200 individuals (mean [SD] age at first biomarker measurement, 42.1 [12.6] years; 122 535 [58.0%] male; 188 895 [89.4%] born in Sweden) participated in the study. During a mean (SD) follow-up of 21.0 (6.7) years, a total of 16 256 individuals were diagnosed with depression, anxiety, or stress-related disorders. High levels of glucose (hazard ratio [HR], 1.30; 95% CI, 1.20-1.41) and triglycerides (HR, 1.15; 95% CI, 1.10-1.20) were associated with an increased subsequent risk of all tested psychiatric disorders, whereas high levels of high-density lipoprotein (HR, 0.88; 95% CI, 0.80-0.97) were associated with a reduced risk. These results were similar for male and female participants as well as for all tested disorders. The nested case-control analyses demonstrated that patients with depression, anxiety, or stress-related disorders had higher levels of glucose, triglycerides, and total cholesterol during the 20 years preceding diagnosis, as well as higher levels of apolipoprotein A-I and apolipoprotein B during the 10 years preceding diagnosis, compared with control participants.

Conclusions and Relevance

In this cohort study of more than 200 000 participants, high levels of glucose and triglycerides and low levels of high-density lipoprotein were associated with future risk of depression, anxiety, and stress-related disorders. These findings may support closer follow-up of individuals with metabolic dysregulations for the prevention and diagnosis of psychiatric disorders.

Peripheral immunity and risk of incident brain disorders: a prospective cohort study of 161,968 participants

Whether peripheral immunity prospectively influences brain health remains controversial. This study aims to investigate the longitudinal associations between peripheral immunity markers with incident brain disorders. A total of 161,968 eligible participants from the UK Biobank were included. We investigated the linear and non-linear effects of peripheral immunity markers including differential leukocytes counts, their derived ratios and C-reactive protein (CRP) on the risk of dementia, Parkinson's disease (PD), stroke, schizophrenia, bipolar affective disorder (BPAD), major depressive disorder (MDD) and anxiety, using Cox proportional hazard models and restricted cubic spline models. Linear regression models were used to explore potential mechanisms driven by brain structures. During a median follow-up of 9.66 years, 16,241 participants developed brain disorders. Individuals with elevated innate immunity markers including neutrophils, monocytes, platelets, neutrophil-to-lymphocyte ratio (NLR), and systemic immune-inflammation index (SII) had an increased risk of brain disorders. Among these markers, neutrophils exhibited the most significant correlation with risk of dementia (hazard ratio 1.08, 95% confidence interval 1.04-1.12), stroke (HR 1.06, 95% CI 1.03-1.09), MDD (HR 1.13, 95% CI 1.10-1.16) and anxiety (HR 1.07, 95% CI 1.04-1.10). Subgroup analysis revealed age-specific and sex-specific associations between innate immunity markers with risk of dementia and MDD. Neuroimaging analysis highlighted the associations between peripheral immunity markers and alterations in multiple cortical, subcortical regions and white matter tracts, typically implicated in dementia and psychiatric disorders. These findings support the hypothesis that neuroinflammation is important to the etiology of various brain disorders, offering new insights into their potential therapeutic approaches.

Testosterone and aging male, a perspective from a developing country

PURPOSE

Hypogonadism is associated with a wide range of physical and psychological symptoms that can affect the overall health of men. However, in a developing country, there are several imposing challenges in the diagnosis and treatment of hypogonadism, including a lack of awareness and understanding of the condition among healthcare providers and patients, limited resources and the high cost of treatment. This review aimed to examine the potential benefits and risks of testosterone replacement therapy (TRT) and provides a perspective of a developing country on the topic.

MATERIALS AND METHODS

A comprehensive literature review was conducted to gather relevant information on the impact of testosterone deficiency on ageing males and the effectiveness of TRT for treating hypogonadism. Published peer-reviewed articles were analyzed to evaluate the benefits and risks of TRT. Additionally, the unique challenges faced in the diagnosis and treatment of hypogonadism in a developing country were considered.

RESULTS

Testosterone replacement therapy has been shown to be an effective treatment for hypogonadism, particularly in symptomatic men with low testosterone levels. It offers potential benefits such as improvements in symptoms and overall quality of life. However, there are associated risks and side effects that need to be considered. In a developing country, challenges such as limited awareness and understanding of hypogonadism, resource constraints, and high treatment costs pose additional barriers to accessing TRT and comprehensive care.

CONCLUSION

In conclusion, TRT holds promise as a treatment for hypogonadism, but its implementation and accessibility face significant challenges in a developing country. Addressing these challenges, including raising awareness, allocating resources, and finding cost-effective solutions, is crucial for ensuring that men with hypogonadism in such settings receive appropriate diagnosis and treatment. Further research and efforts are needed to improve the management of hypogonadism in developing countries and optimize the potential benefits of TRT for affected individuals.

Liver function test indices-based prediction model for post-stroke depression: a multicenter, retrospective study

BACKGROUND

Post-stroke depression (PSD) was one of the most prevalent and serious neuropsychiatric effects after stroke. Nevertheless, the association between liver function test indices and PSD remains elusive, and there is a lack of effective prediction tools. The purpose of this study was to explore the relationship between the liver function test indices and PSD, and construct a prediction model for PSD.

METHODS

All patients were selected from seven medical institutions of Chongqing Medical University from 2015 to 2021. Variables including demographic characteristics and liver function test indices were collected from the hospital electronic medical record system. Univariate analysis, least absolute shrinkage and selection operator (LASSO) and logistic regression analysis were used to screen the predictors. Subsequently, logistic regression, random forest (RF), extreme gradient boosting (XGBoost), gradient boosting decision tree (GBDT), categorical boosting (CatBoost) and support vector machine (SVM) were adopted to build the prediction model. Furthermore, a series of evaluation indicators such as area under curve (AUC), sensitivity, specificity, F1 were used to assess the performance of the prediction model.

RESULTS

A total of 464 PSD and 1621 stroke patients met the inclusion criteria. Six liver function test items, namely AST, ALT, TBA, TBil, TP, ALB/GLB, were closely associated with PSD, and included for the construction of the prediction model. In the test set, logistic regression model owns the AUC of 0.697. Compared with the other four machine learning models, the GBDT model has the best predictive performance (F1 = 0.498, AUC = 0.761) and was chosen to establish the prediction tool.

CONCLUSIONS

The prediction model constructed using these six predictors with GBDT algorithm displayed a promising prediction ability, which could be used for the participating hospital units or individuals by mobile phone or computer.

Major depressive disorder: biomarkers and biosensors

Depressive disorders belong to highly heterogeneous psychiatric diseases. Loss of in interest in previously enjoyed activities and a depressed mood are the main characteristics of major depressive disorder (MDD). Moreover, due to significant heterogeneity in clinical presentation and lack of applicable biomarkers, diagnosis and treatment remains challenging. Identification of relevant biomarkers would allow for improved disease classification and more personalized treatment strategies. Herein, we review the current state of these biomarkers and then discuss diagnostic techniques of aimed to specifically target these analytes using state of the art biosensor technology.

Association of serum alkaline phosphatase and depression in US adults: a population-based cross-sectional study

Background

Depression, a serious public health disorder, is increasingly prevalent worldwide. An association between alkaline phosphatase (ALP) and neurological disorders has been reported. However, data on ALP and depression risk are scarce, which warrants attention.

Methods

We assessed the association between ALP and risk of depression in adults from the 2007-2014 National Health and Nutrition Examination Survey (NHANES). Depression was assessed using the Patient Health Questionnaire-9. Univariate and multivariate logistic regression were used to assess the association between ALP and risk of depression, and subgroup analyses were also performed.

Results

A total of 17,485 participants were included. The prevalence of depression was 9.3% (1,631/17,485) and ALP was significantly associated with the risk of depression when ALP was a categorical variable (quadratic or categorized by 79 U/L) in a multivariate logistic regression model after adjusting for confounding factors (≥79 U/L vs. <79 U/L, adjusted OR, 1.15; 95%CI, 1.02-1.29). Each 1-unit increase in ALP (log₂) was associated with a 20% increase in depression prevalence (adjusted OR, 1.20; 95%CI, 1.06-1.36) when ALP was used as a continuous variable. Subgroup analysis showed that ALP was positively associated with the risk of depression with different characteristics.

Conclusion

Our findings suggest that higher alkaline phosphatase levels, even within the normal range, are significantly associated with a higher risk of depression in US adults. Such findings require further prospective studies to provide more evidence.

Women's mood at high altitude. sexual dimorphism in hypoxic stress modulation by the tryptophan-melatonin axis

Sexual (and gender)-dimorphism in tolerance to hypobaric hypoxia increasingly matters for a differential surveillance of human activities at high altitude (HA). At low altitudes, the prevalence of anxiety and depression in women has already been found to double when compared with men; it could be expected to even increase on exposure to HA. In purposefully caring for the health of women at HA, the present work explores the potential involvement of the tryptophan (Trp)-melatonin axis in mood changes on exposure to hypobaric hypoxia. The present work highlights some already known anxiogenic effects of HA exposure. Hypoxia and insomnia reduce serotonin (5-HT) availability; the latter defect being expressed as failure of brown adipose tissue (BAT) activation and mood disorders. Rapid eye movement (REM) sleep organization and synapsis restoration that are additionally affected by hypoxia impair memory consolidation. Affective complaints may thus surge, evolving into anxiety and depression. Sex-related differences in neural network organization and hormonal changes during the menstrual cycle, and certainly also during the life cycle, underscore the possibility of 5-HT-related mood alterations, particularly in women on HA exposure. The mean brain rate of 5-HT synthesis at sea level is already 1.5-fold higher in males than in females. sexual dimorphism also evidences the overexpression effects of SERT, a 5-HT transporter protein. Gonadal and thyroid hormones, as influenced by HA exposure, further modulate 5-HT availability and its effects in women. Besides caring for adequate oxygenation and maintenance of one's body core temperature, special precautions concerning women sojourning at HA should include close observations of hormonal cycles and, perhaps, also trials with targeted antidepressants.

The role of testosterone, the androgen receptor, and hypothalamic-pituitary-gonadal axis in depression in ageing Men

Considerable research has shown that testosterone regulates many physiological systems, modulates clinical disorders, and contributes to health outcome. However, studies on the interaction of testosterone levels with depression and the antidepressant effect of testosterone replacement therapy in hypogonadal men with depression have been inconclusive. Current findings indicate that low circulating levels of total testosterone meeting stringent clinical criteria for hypogonadism and testosterone deficiency induced by androgen deprivation therapy are associated with increased risk for depression and current depressive symptoms. The benefits of testosterone replacement therapy in men with major depressive disorder and low testosterone levels in the clinically defined hypogonadal range remain uncertain and require further investigation. Important considerations going forward are that major depressive disorder is a heterogeneous phenotype with depressed individuals differing in inherited polygenic determinants, onset and clinical course, symptom complexes, and comorbidities that contribute to potential multifactorial differences in pathophysiology. Furthermore, polygenic mechanisms are likely to be critical to the biological heterogeneity that influences testosterone-depression interactions. A genetically informed precision medicine approach using genes regulating testosterone levels and androgen receptor sensitivity will likely be essential in gaining critical insight into the role of testosterone in depression.

Serum clinical laboratory tests and risk of incident dementia: a prospective cohort study of 407,190 individuals

Prevention of dementia is a public health priority, and the identification of potential biomarkers may provide benefits for early detection and prevention. This study investigates the association of common serum laboratory tests with the risk of incident dementia. Among 407,190 participants from the UK Biobank (median follow-up of 9.19 years), we investigated the linear and nonlinear effects of 30 laboratory measures on the risk of all-cause dementia using Cox models and restricted cubic spline models. We found that dementia incidence was associated with low vitamin D concentration (hazard ratio 0.994, 95% confidence interval 0.993-0.996), indicators of endocrine disorders: IGF-1 level (P for non-linearity = 1.1E-05), testosterone level (P for non-linearity = 0.006); high sex-hormone-binding globulin level (HR 1.004, 95% CI: 1.003-1.006); reduced liver function: lower alanine aminotransferase (HR 0.990, 95% CI: 0.986-0.995); renal dysfunction: cystatin C level (P for non-linearity = 0.028); oxidative stress: lower urate level (HR 0.998, 95% CI: 0.998-0.999); lipids dysregulation: lower LDL (HR 0.918, 95% CI: 0.872-0.965) and triglycerides (HR 0.924, 95% CI: 0.882-0.967) concentrations; insulin resistance: high glucose (HR 1.093, 95% CI: 1.045-1.143) and HbA1c (HR 1.017, 95% CI: 1.009-1.025) levels; immune dysbiosis: C-reactive protein (P for non-linearity = 5.5E-09). In conclusion, markers of vitamin D deficiency, GH-IGF-1 axis disorders, bioactive sex hormone deficiency, reduced liver function, renal abnormalities, oxidation, insulin resistance, immune dysbiosis, and lipids dysregulation were associated with incident dementia. Our results support a contributory role of systemic disorders and diverse biological processes to onset of dementia.