Hair glucocorticoid levels in Parkinson's disease

Cortisol in metabolic syndrome

Cortisol, a stress hormone, plays a crucial role in regulating metabolic, hemodynamic, inflammatory, and behavioral processes. Its secretion is governed by the hypothalamic-pituitary-adrenal axis. However, prolonged activation of this axis and increased cortisol bioavailability in tissues can result in detrimental metabolic effects. Chronic exposure to excessive cortisol is associated with insulin resistance and visceral obesity, both significant contributors to metabolic syndrome. This review delves into the regulation of the hypothalamic-pituitary-adrenal axis, the molecular mechanisms underlying cortisol synthesis and its actions, as well as the key factors influencing cortisol bioavailability. Furthermore, it provides a summary of available clinical research data on the involvement of cortisol in metabolic syndrome, alongside a discussion on the various biomatrices used for cortisol measurement in clinical settings.

Alleviating Stress in Parkinson's Disease: Symptomatic Treatment, Disease Modification, or Both?

Psychological stress, a state of mental strain caused by mentally or physically threatening situations, plays a significant role in Parkinson's disease (PD). Motor symptoms worsen during acute stress and common non-motor symptoms in PD, such as anxiety and depression, are linked to chronic stress. Although evidence in humans is lacking, animal models of PD suggest that chronic stress can accelerate dopaminergic cell death. This suggests that stress-reducing interventions have not only symptomatic, but perhaps also disease-modifying effects. Our objective was to identify the most promising strategies for stress-reduction in PD and to analyze their potential value for disease-modification. An unstructured literature search was performed, primarily focusing on papers published between 2020-2023. Several large clinical trials have tested the efficacy of aerobic exercise and mindfulness-based interventions on PD symptoms. The evidence is promising, but not definitive yet: some exercise trials found a reduction in stress-related symptoms, whereas others did not or did not report it. In the majority of trials, biological measures of stress and of disease progression are missing. Furthermore, follow-up periods were generally too short to measure disease-modifying effects. Hence, mechanisms underlying the intervention effects remain largely unclear. These effects may consist of attenuating progressive neurodegeneration (measured with MRI-markers of substantia nigra integrity or cortical thickness), or a strengthening of compensatory cerebral mechanisms (measured with functional neuroimaging), or both. Lifestyle interventions are effective for alleviating stress-related symptoms in PD. They hold potential for exerting disease-modifying effects, but new evidence in humans is necessary to fulfill that promise.

Long-term glucocorticoids in relation to the metabolic syndrome and cardiovascular disease: A systematic review and meta-analysis

The striking link of Cushing's syndrome with the metabolic syndrome (MetS) and cardiovascular disease (CVD) suggests that long-term exposure to extremely high cortisol levels catalyzes cardiometabolic deterioration. However, it remained unclear whether the findings from the extreme glucocorticoid overabundance observed in Cushing's syndrome could be translated into more subtle variations in long-term glucocorticoid levels among the general population, for example, due to chronic stress. Here, we performed a systematic review (PROSPERO: CRD42023425541) of evidence regarding the role of subtle variations in long-term biological stress, measured as levels of scalp hair cortisol (HairF) and cortisone (HairE), in the context of MetS and CVD in adults. We also performed a meta-analysis on the cross-sectional difference in HairF levels between individuals with versus without CVD. Seven studies were included regarding MetS, sixteen regarding CVD, and one regarding both. Most articles indicated a strong, consistent cross-sectional association of higher HairF and HairE levels with CVD, which was confirmed by our meta-analysis for HairF (eight studies, SMD = 0.48, 95% confidence intervals [CIs]: 0.16-0.79, p = 0.0095). Moreover, these relationships appear largely independent of standard risk factors. Age seems relevant as the effect seems stronger in younger individuals. Results regarding the associations of HairF and HairE with MetS were inconsistent. Altogether, long-term biological stress, measured as HairF and HairE, is associated with the presence of CVD, and less consistently with MetS. Prospective studies need to evaluate the directionality of this relationship and determine whether HairF and HairE can be used in addition to standard risk factors in predicting future cardiometabolic deterioration.

Multidirectional associations between the gut microbiota and Parkinson's disease, updated information from the perspectives of humoral pathway, cellular immune pathway and neuronal pathway

The human gastrointestinal tract is inhabited by a diverse range of microorganisms, collectively known as the gut microbiota, which form a vast and complex ecosystem. It has been reported that the microbiota-gut-brain axis plays a crucial role in regulating host neuroprotective function. Studies have shown that patients with Parkinson's disease (PD) have dysbiosis of the gut microbiota, and experiments involving germ-free mice and fecal microbiota transplantation from PD patients have revealed the pathogenic role of the gut microbiota in PD. Interventions targeting the gut microbiota in PD, including the use of prebiotics, probiotics, and fecal microbiota transplantation, have also shown efficacy in treating PD. However, the causal relationship between the gut microbiota and Parkinson's disease remains intricate. This study reviewed the association between the microbiota-gut-brain axis and PD from the perspectives of humoral pathway, cellular immune pathway and neuronal pathway. We found that the interactions among gut microbiota and PD are very complex, which should be "multidirectional", rather than conventionally regarded "bidirectional". To realize application of the gut microbiota-related mechanisms in the clinical setting, we propose several problems which should be addressed in the future study.

Targeting neuroendocrine abnormalities in Parkinson's disease with exercise

Parkinson's Disease (PD) is a prevalent and complex age-related neurodegenerative condition for which there are no disease-modifying treatments currently available. The pathophysiological process underlying PD remains incompletely understood but increasing evidence points to multiple system dysfunction. Interestingly, the past decade has produced evidence that exercise not only reduces signs and symptoms of PD but is also potentially neuroprotective. Characterizing the mechanistic pathways that are triggered by exercise and lead to positive outcomes will improve understanding of how to counter disease progression and symptomatology. In this review, we highlight how exercise regulates the neuroendocrine system, whose primary role is to respond to stress, maintain homeostasis and improve resilience to aging. We focus on a group of hormones - cortisol, melatonin, insulin, klotho, and vitamin D - that have been shown to associate with various non-motor symptoms of PD, such as mood, cognition, and sleep/circadian rhythm disorder. These hormones may represent important biomarkers to track in clinical trials evaluating effects of exercise in PD with the aim of providing evidence that patients can exert some behavioral-induced control over their disease.

The Interrelated Multifactorial Actions of Cortisol and Klotho: Potential Implications in the Pathogenesis of Parkinson's Disease

The pathogenesis of Parkinson's disease (PD) is complex, multilayered, and not fully understood, resulting in a lack of effective disease-modifying treatments for this prevalent neurodegenerative condition. Symptoms of PD are heterogenous, including motor impairment as well as non-motor symptoms such as depression, cognitive impairment, and circadian disruption. Aging and stress are important risk factors for PD, leading us to explore pathways that may either accelerate or protect against cellular aging and the detrimental effects of stress. Cortisol is a much-studied hormone that can disrupt mitochondrial function and increase oxidative stress and neuroinflammation, which are recognized as key underlying disease mechanisms in PD. The more recently discovered klotho protein, considered a general aging-suppressor, has a similarly wide range of actions but in the opposite direction to cortisol: promoting mitochondrial function while reducing oxidative stress and inflammation. Both hormones also converge on pathways of vitamin D metabolism and insulin resistance, also implicated to play a role in PD. Interestingly, aging, stress and PD associate with an increase in cortisol and decrease in klotho, while physical exercise and certain genetic variations lead to a decrease in cortisol response and increased klotho. Here, we review the interrelated opposite actions of cortisol and klotho in the pathogenesis of PD. Together they impact powerful and divergent mechanisms that may go on to influence PD-related symptoms. Better understanding of these hormones in PD would facilitate the design of effective interventions that can simultaneously impact the multiple systems involved in the pathogenesis of PD.

Hair cortisol levels in schizophrenia and metabolic syndrome

AIM

Individuals with schizophrenia demonstrate higher rates of metabolic syndrome (MetS) than the general population. Hair cortisol concentrations (HCC) reflect longer-term cortisol secretion and can provide additional insights into the role of the hypothalamic pituitary adrenal (HPA) axis in schizophrenia and co-occurring MetS.

METHODS

In a case-control study of 16 patients with schizophrenia (11 first episode psychosis [FEP] and 5 chronic) and 21 controls hair samples, representing a 3-month retrospective window of cortisol, were collected and analysed utilizing liquid chromatography tandem mass spectrometry. We investigated whether schizophrenia and MetS co-occurrence were associated with HCC utilizing multivariate regression models. We also explored the longitudinal trajectory of HCC in FEP patients by conducting a mixed models analysis.

RESULTS

At baseline HCC were significantly lower (Cohen's d = 0.88) in patients with schizophrenia than in controls (p = .014). HCC increased from baseline to month-12 in FEP patients compared to controls, demonstrating a trend towards significance (p = .097). MetS was not associated with HCC at baseline, but HCC increased significantly from baseline to month-12 in relation to MetS (p = .037).

CONCLUSIONS

In a subgroup of schizophrenia patients, psychosis may be associated with a blunted HPA axis with lower long-term cortisol output. MetS was associated with an increase in HCC and elevated cortisol levels observed in schizophrenia may be related to increased rates of MetS in schizophrenia patients.

Immunosuppressants contribute to a reduced risk of Parkinson's disease in rheumatoid arthritis

BACKGROUND

Observational studies have suggested a decreased risk of Parkinson's disease (PD) in patients with rheumatoid arthritis (RA). However, the results are controversial and the biological mechanism underlying this effect remains largely unknown.

METHODS

The effect sizes of five observational studies were summarized to determine the association between RA and PD. A two-step Mendelian randomization (TSMR) analysis was conducted using genome-wide association studies data sets of RA, PD and prescription of non-steroidal anti-inflammatory drugs (NSAIDs), immunosuppressants (IS) and glucocorticoids (GC). A multivariable MR (MVMR) was also performed to verify the impact of prescription history on PD risk.

RESULTS

Integrated data from observational studies showed that RA was associated with a decreased risk of PD in the European population (effect size = -0.38, P = 0.004). We found that genetically predicted RA was correlated with a decreased risk of PD [odds ratio (OR) = 0.91, P = 0.007]. In the TSMR, RA patients tended to have an increased prescription of GC (OR = 1.16, P = 2.96e - 07) and IS (OR = 1.77, P = 5.58e - 64), which reduced the risk of PD (GC: OR = 0.86, P = 0.0270; IS: OR = 0.82, P = 0.0277), respectively. Further MVMR analysis demonstrated that only IS was linked to a decreased risk of PD (OR = 0.86, P = 0.004).

CONCLUSION

This work clarified that patients with RA had a decreased risk of PD, which was partially attributed to the use of IS in RA patients but not GC or NSAIDs.

The relationship of hair glucocorticoid levels to immunological and virological outcomes in a large cohort of combination antiretroviral therapy treated people living with HIV

Background

Existing literature mostly investigated the relationship of acute or short-term glucocorticoid exposure to HIV disease progression using cortisol levels in serum, saliva, or urine. Data are limited on the relationship of long-term glucocorticoid exposure to HIV disease progression. This study examined whether hair glucocorticoid levels, novel retrospective indicators of long-term glucocorticoid exposure, are associated with two common indicators of HIV disease progression (CD4 count and HIV viral load) among a large cohort of combination antiretroviral therapy treated Chinese people living with HIV (PLHIV).

Methods

A total of 1198 treated PLHIV provided hair samples for glucocorticoid (cortisol and cortisone) assay and completed a survey assessing sociodemographic, lifestyle, and HIV-related characteristics. Meanwhile, CD4 count and HIV viral load were retrieved from their medical records. Spearman correlation was used to examine the associations of hair cortisol and cortisone levels to continuous CD4 count and HIV viral load. Multivariate logistic regression was used to predict CD4 count < 500 cells/mm³.

Results

Both hair cortisol and cortisone levels were negatively associated with CD4 count but not with HIV viral load. The odds ratio for CD4 count < 500 cells/mm³ was 1.41 [95% CI 0.99–2.00] and 2.15 [95% CI 1.51–3.05] for those with hair cortisol and cortisone levels in the highest quartile compared to the lowest when controlling for sociodemographic, lifestyle, HIV-related covariates, and HIV viral load.

Conclusion

Hair glucocorticoid levels were associated with CD4 count but not viral load in treated Chinese PLHIV. Our data furtherly supported the hypothesis that elevated glucocorticoid levels are associated with the lower CD4 count.

Cross-sectional relation of long-term glucocorticoids in hair with anthropometric measurements and their possible determinants: A systematic review and meta-analysis

BACKGROUND

Long-term glucocorticoids (HairGC) measured in scalp hair have been associated with body mass index (BMI), waist circumference (WC), and waist-hip-ratio (WHR) in several cross-sectional studies. We aimed to investigate the magnitude, strength, and clinical relevance of these relations across all ages.

METHODS

We performed a systematic review and meta-analysis (PROSPERO registration CRD42020205187) searching for articles relating HairGC to measures of obesity. Main outcomes were bivariate correlation coefficients and unadjusted simple linear regression coefficients relating hair cortisol (HairF) and hair cortisone (HairE) to BMI, WC, and WHR.

RESULTS

We included k = 146 cohorts (n = 34,342 individuals). HairGC were positively related to all anthropometric measurements. The strongest correlation and largest effect size were seen for HairE-WC: pooled correlation 0.18 (95%CI 0.11-0.24; k = 7; n = 3,158; I²  = 45.7%) and pooled regression coefficient 11.0 cm increase in WC per point increase in 10-log-transformed HairE (pg/mg) on liquid-chromatography-(tandem) mass spectrometry (LC-MS) (95%CI 10.1-11.9 cm; k = 6; n = 3,102). Pooled correlation for HairF-BMI was 0.10 (95%CI 0.08-0.13; k = 122; n = 26,527; I²  = 51.2%) and pooled regression coefficient 0.049 kg/m² per point increase in 10-log-transformed HairF (pg/mg) on LC-MS (95%CI 0.045-0.054 kg/m² ; k = 26; n = 11,635).

DISCUSSION

There is a consistent positive association between HairGC and BMI, WC, and WHR, most prominently and clinically relevant for HairE-WC. These findings overall suggest an altered setpoint of the hypothalamic-pituitary-adrenal axis with increasing central adiposity.

The association between hair cortisol levels, inflammation and cognitive functioning in females

Glucocorticoids and inflammatory markers can influence cognitive function. Hair cortisol concentrations (HCC) reflect longer-term hypothalamic pituitary adrenal (HPA) axis function and combined with immune markers can provide insights into how HPA-axis and immune pathways interact to influence cognition. We examined the association between HCC and high sensitivity c-reactive protein (hsCRP) levels, as well as the interaction between HCC and hsCRP, and cognitive function in a sample of 153 females, aged between 18 and 79 years, from a cross-sectional case-control study (SHARED ROOTS), conducted in Cape Town, South Africa from May 2014 until June 2017. We examined whether HCC and hsCRP levels were associated with performance on neurocognitive tests in both unadjusted and adjusted linear regression models. HCC demonstrated a significant inverse association with verbal working memory in both unadjusted (p = 0.010) and adjusted (p = 0.016) analyses. There were significant interactions between HCC and hsCRP on verbal intelligence (p = 0.016), language (p = 0.023) and executive function (p = 0.008) scores, such that at low HCC hsCRP levels were positively associated with language (p = 0.020) and executive function (p = 0.006) scores and at high HCC hsCRP levels were inversely associated with verbal intelligence (p = 0.034) scores. Though the results did not survive correction for multiple comparisons, they suggest stress-related neuroendocrine effects on working memory impairment. Furthermore, under physiological conditions and low long-term HCC, there may be positive effects of peripheral inflammatory markers on cognitive performance, whereas there may be detrimental effects when the HPA-axis is dysregulated as reflected by high long-term cortisol output.

Association between hair cortisol, hair cortisone, and fatigue in people living with HIV

Cumulative evidence to date largely supports an association between dysregulation of the activity of the hypothalamic-pituitary-adrenal (HPA) axis and fatigue. People living with HIV (PLHIV), in particular, are vulnerable to both HPA axis dysregulation and fatigue. Few investigations have examined the possible role of HPA-axis dysfunction in the occurrence of fatigue in PLHIV. This cross-sectional study aimed to investigate the association between glucocorticoids in hair, retrospective indicators of long-term HPA axis activity and biomarkers of chronic stress, and fatigue in PLHIV. A total of 446 PLHIV from Guangxi China provided hair samples for cortisol and cortisone assay and provided information on fatigue levels, sociodemographic, lifestyle, and HIV-related characteristics. Results showed that before and after controlling sociodemographic, lifestyle, and HIV-related characteristics, hair cortisone levels, but not hair cortisol levels, were associated with fatigue levels in PLHIV. In conclusion, we found that higher cortisone levels are associated with greater fatigue levels in a large cohort of Chinese PLHIV.LAY SUMMARYWe found that hair cortisone levels were significantly associated with fatigue levels in a large cohort of Chinese PLHIV. Hair cortisol levels were, however, not associated with fatigue levels in the PLHIV studied. We thus show that Chinese PLHIV who have higher cortisone levels are associated with higher fatigue levels.

Impact of Glucocorticoid on a Cellular Model of Parkinson's Disease: Oxidative Stress and Mitochondrial Function

Stress seems to contribute to the neuropathology of Parkinson's disease (PD), possibly by dysregulation of the hypothalamic-pituitary-adrenal axis. Oxidative distress and mitochondrial dysfunction are key factors involved in the pathophysiology of PD and neuronal glucocorticoid-induced toxicity. Animal PD models have been generated to study the effects of hormonal stress, but no in vitro model has yet been developed. Our aim was to examine the impact of corticosterone (CORT) administration on a dopaminergic neuronal cell model of PD induced by the neurotoxin MPP⁺, as a new combined PD model based on the marker of endocrine response to stress, CORT, and oxidative-mitochondrial damage. We determined the impact of CORT, MPP⁺ and their co-incubation on reactive oxygen species production (O2^-•), oxidative stress cellular markers (advanced-oxidation protein products and total antioxidant status), mitochondrial function (mitochondrial membrane potential and mitochondrial oxygen consumption rate) and neurodegeneration (Fluoro-Jade staining). Accordingly, the administration of MPP⁺ or CORT individually led to cell damage compared to controls (p < 0.05), as determined by several methods, whereas their co-incubation produced strong cell damage (p < 0.05). The combined model described here could be appropriate for investigating neuropathological hallmarks and for evaluating potential new therapeutic tools for PD patients suffering mild to moderate emotional stress.

Greater Pain Severity is Associated with Higher Glucocorticoid Levels in Hair Among a Cohort of People Living with HIV

Background

Pain is a common occurrence and persistent symptom, which has an adverse impact on individual well-being and quality of life among people living with HIV (PLHIV). Alteration in the activity of the Hypothalamic-Pituitary-Adrenal (HPA) axis resulting in abnormal glucocorticoid levels had been proposed to play important roles in those associations.

Purpose

This study aimed to investigate whether pain severity was associated with hair glucocorticoid levels, a novel method of measuring long-term glucocorticoid exposure, among a large cohort of Chinese PLHIV.

Methods

A measure of pain severity and hair samples were collected from 431 adults PLHIV in Guangxi, China. Glucocorticoid (cortisol and cortisone) in hair were quantified by liquid chromatography-tandem mass spectrometry. The general linear model was used to test the associations of pain severity with hair glucocorticoid levels after adjusting for potential confounding factors.

Results

Of the 431 PLHIV, 273 reported none pain, 87 reported mild pain, and 71 reported moderate-severe pain. Hair cortisone, but not hair cortisol, was found to differ significantly among the three pain severity groups (F=3.90, p=0.021). PLHIV reported moderate-severe pain had higher hair cortisone than those reported mild (p=0.070) or none pain (p=0.014), with no differences between the latter two pain severity groups.

Conclusion

Greater pain severity is associated with higher hair cortisone levels among Chinese PLHIV. In order to reduce the long-term glucocorticoid levels, interventions managing pain should be considered for PLHIV with moderate-severe pain.

Glucocorticoid impairs mitochondrial quality control in neurons

Neurons are particularly vulnerable to mitochondrial dysfunction due to high energy demand and an inability to proliferate. Therefore, dysfunctional mitochondria cause various neuropathologies. Mitochondrial damage induces maintenance pathways to repair or eliminate damaged organelles. This mitochondrial quality control (MQC) system maintains appropriate morphology, localization, and removal/replacement of mitochondria to sustain brain homeostasis and counter progression of neurological disorders. Glucocorticoid release is an essential response to stressors for adaptation; however, it often culminates in maladaptation if neurons are exposed to chronic and severe stress. Long-term exposure to high levels of glucocorticoids induces mitochondrial dysfunction via genomic and nongenomic mechanisms. Glucocorticoids induce abnormal mitochondrial morphology and dysregulate fusion and fission. Moreover, mitochondrial trafficking is arrested by glucocorticoids and dysfunctional mitochondria are subsequently accumulated around the soma. These alterations lead to energy deficiency, particularly for synaptic transmission that requires large amounts of energy. Glucocorticoids also impair mitochondrial clearance by preventing mitophagy of damaged organelle and suppress mitochondrial biogenesis, resulting in the reduced number of healthy mitochondria. Failure to maintain MQC degrades brain function and contributes to neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Huntington's disease. However, mechanisms of glucocorticoid action on the regulation of MQC during chronic stress conditions are not well understood. The present review discusses pathways involved in the impairment of MQC and the clinical significance of high glucocorticoid blood levels for neurodegenerative diseases.

Effect of Metabolic Syndrome on Parkinson's Disease: A Systematic Review

Evidence shows that metabolic syndrome (MS) is associated with a greater risk of developing Parkinson's disease (PD) because of the increase in oxidative stress levels along with other factors such as neuroinflammation and mitochondrial dysfunction. However, because some studies have reported that MS is associated with a lower risk of PD, the relationship between MS and PD should be investigated. This study aimed to investigate the effect of MS on PD. Two authors searched five electronic databases, namely, MEDLINE, PubMed, Scopus, PsycINFO, Web of Science, and Science Direct, for relevant articles between September and October 2020. After screening the title and abstract of all articles, 34 articles were selected for full-text review. Finally, 11 articles meeting the eligibility criteria were included in the study. The quality of articles was critically evaluated using the Joanna Briggs Institute. Overall, we evaluated data from 23,586,349 individuals (including healthy individuals, with MS and PD) aged 30 years or more. In cohort studies, the follow-up period varied between 2 and 30 years. MS contributed considerably to the increase in the incidence of PD. In addition, obesity, a component of MS, alone can increase the probability of developing neurodegenerative diseases. However, despite few studies on MS and PD, changes in cognitive function and more rapid progression of PD disease has been documented in patients with MS using methods commonly used in research.

Stress and Mindfulness in Parkinson's Disease: Clinical Effects and Potential Underlying Mechanisms

Patients with Parkinson's disease (PD) are very vulnerable to the negative effects of psychological distress: neuropsychiatric symptoms, such as anxiety and depression, are highly prevalent in PD; motor symptoms (such as tremor) typically worsen in stressful situations; and dopaminergic medication is less effective. Furthermore, animal studies of PD suggest that chronic stress may accelerate disease progression. Adequate self-management strategies are therefore essential to reduce the detrimental effects of chronic stress on PD. Mindfulness-based interventions encourage individuals to independently self-manage and adapt to the challenges created by their condition. In PD, emerging clinical evidence suggests that mindfulness-based interventions may reduce psychological distress and improve clinical symptoms, but insight into the underlying mechanisms is lacking. In this viewpoint, we provide a systematic overview of existing mindfulness trials in PD. Furthermore, we discuss the cerebral mechanisms involved in acute and chronic stress, and the impact of mindfulness-based interventions on these networks. In addition, we delineate a hypothetical mechanistic framework of how chronic stress may increase the susceptibility for neuropsychiatric symptoms in PD and may potentially even influence disease progression. We end with offering recommendations for future research. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.