Lipids, Apolipoproteins, and the Risk of Parkinson Disease

The diagnostic value of neutrophil to lymphocyte ratio, albumin to fibrinogen ratio, and lymphocyte to monocyte ratio in Parkinson's disease: a retrospective study

Background

Parkinson's disease (PD) is a prevalent disorder of the central nervous system, marked by the degeneration of dopamine (DA) neurons in the ventral midbrain. In the pathogenesis of PD, inflammation hypothesis has been concerned. This study aims to investigate clinical indicators of peripheral inflammation in PD patients and to explore the diagnostic value of neutrophil-to-lymphocyte ratio (NLR), albumin-to-fibrinogen ratio (AFR), and lymphocyte-to-monocyte ratio (LMR) in assessing PD risk.

Methods

This study included 186 patients with PD and 201 matched healthy controls (HC) with baseline data. Firstly, the differences of hematological indicators between PD group and healthy participants were compared and analyzed. Univariate and multivariate regression analyses were then conducted. Smooth curve fitting was applied to further validate the relationships between NLR, LMR, AFR, and PD. Subsequently, subgroup analysis was conducted in PD group according to different duration of disease and Hoehn and Yahr (H&Y) stage, comparing differences in clinical indicators. Finally, the receiver operating characteristic (ROC) curve was employed to assess the diagnostic value of NLR, LMR, and AFR in PD.

Results

Compared to the HC group, the PD group showed significantly higher levels of hypertension, diabetes, neutrophil count, monocyte count, CRP, homocysteine, fibrinogen, and NLR. Conversely, levels of LMR, AFR, lymphocyte count, HDL, LDL, TG, TC, uric acid, and albumin were significantly lower. The multivariate regression model indicated that NLR (OR = 1.79, 95% CI: 1.39-2.31, p < 0.001), LMR (OR = 0.75, 95% CI: 0.66-0.85, p < 0.001), and AFR (OR = 0.79, 95% CI: 0.73-0.85, p < 0.001) were significant factors associated with PD. Smooth curve fitting revealed that NLR was positively linked to PD risk, whereas AFR and LMR were inversely associated with it. In ROC curve analysis, the AUC of AFR was 0.7290, the sensitivity was 63.98%, and the specificity was 76.00%. The AUC of NLR was 0.6200, the sensitivity was 50.54%, and the specificity was 71.50%. The AUC of LMR was 0.6253, the sensitivity was 48.39%, and the specificity was 73.00%. The AUC of the combination was 0.7498, the sensitivity was 74.19%, and the specificity was 64.00%.

Conclusion

Our findings indicate that NLR, LMR, and AFR are significantly associated with Parkinson's disease and may serve as diagnostic markers.

Serum cholesterol levels and Parkinson's disease: a detailed investigation in Turkish population

OBJECTIVES

Parkinson's disease (PD) involves the progressive loss of dopaminergic neurons and the accumulation of α-synuclein. Elevated cholesterol levels may exacerbate α-synuclein aggregation, potentially contributing to PD. This study investigates the link between lipid profiles and PD severity, as well as cognitive functions in patients, aiming to inform pathogenesis and management strategies.

METHODS

Data from 250 PD patients and 100 healthy controls were analyzed. Serum cholesterol levels were compared with disease severity using Unified Parkinson's Disease Rating Scale (UPDRS) and modified Hoehn & Yahr Rating Scale (mH&Y). Mini-Mental State Examination (MMSE) assessed cognitive functions.

RESULTS

Of the participants, 45.4% were female, 54.6% male, with a mean age of 69.09 ± 11.13 years. Mean UPDRS score was 52.34 ± 26.32, mH&Y was 2.28 ± 0.91. Patients had significantly higher HDL levels (47.92 ± 11.63) than controls (45.40 ± 13.89) (p = 0.024). HDL levels were significantly higher in patients with cognitive impairment than in patients with cognitive normal (p = 0.004). On the contrary, triglyceride levels were significantly lower in those with cognitive impairment compared to those with cognitively normal (p = 0.005). Multivariate logistic regression showed being male associated with 3.796 times higher risk of illness, and HDL is associated with 1.030 times increased illness risk.

CONCLUSION

High HDL levels and male gender particularly increase the risk of Parkinson's disease. Additionally, HDL and triglyceride levels affect the cognition of PD patients. Further studies on the impact of cholesterol metabolism on the pathogenesis of PD could contribute to identifying effective treatment targets.

Metabolic profiling reveals circulating biomarkers associated with incident and prevalent Parkinson's disease

The metabolic profile predating the onset of Parkinson's disease (PD) remains unclear. We aim to investigate the metabolites associated with incident and prevalent PD and their predictive values in the UK Biobank participants with metabolomics and genetic data at the baseline. A panel of 249 metabolites was quantified using a nuclear magnetic resonance analytical platform. PD was ascertained by self-reported history, hospital admission records and death registers. Cox proportional hazard models and logistic regression models were used to investigate the associations between metabolites and incident and prevalent PD, respectively. Area under receiver operating characteristics curves (AUC) were used to estimate the predictive values of models for future PD. Among 109,790 participants without PD at the baseline, 639 (0.58%) individuals developed PD after one year from the baseline during a median follow-up period of 12.2 years. Sixty-eight metabolites were associated with incident PD at nominal significance (P < 0.05), spanning lipids, lipid constituent of lipoprotein subclasses and ratios of lipid constituents. After multiple testing corrections (P < 9 × 10-4), polyunsaturated fatty acids (PUFA) and omega-6 fatty acids remained significantly associated with incident PD, and PUFA was shared by incident and prevalent PD. Additionally, 14 metabolites were exclusively associated with prevalent PD, including amino acids, fatty acids, several lipoprotein subclasses and ratios of lipids. Adding these metabolites to the conventional risk factors yielded a comparable predictive performance to the risk-factor-based model (AUC = 0.766 vs AUC = 0.768, P = 0.145). Our findings suggested metabolic profiles provided additional knowledge to understand different pathways related to PD before and after its onset.

Interaction between α-Synuclein and Bioactive Lipids: Neurodegeneration, Disease Biomarkers and Emerging Therapies

The present review provides a comprehensive examination of the intricate dynamics between α-synuclein, a protein crucially involved in the pathogenesis of several neurodegenerative diseases, including Parkinson's disease and multiple system atrophy, and endogenously-produced bioactive lipids, which play a pivotal role in neuroinflammation and neurodegeneration. The interaction of α-synuclein with bioactive lipids is emerging as a critical factor in the development and progression of neurodegenerative and neuroinflammatory diseases, offering new insights into disease mechanisms and novel perspectives in the identification of potential biomarkers and therapeutic targets. We delve into the molecular pathways through which α-synuclein interacts with biological membranes and bioactive lipids, influencing the aggregation of α-synuclein and triggering neuroinflammatory responses, highlighting the potential of bioactive lipids as biomarkers for early disease detection and progression monitoring. Moreover, we explore innovative therapeutic strategies aimed at modulating the interaction between α-synuclein and bioactive lipids, including the development of small molecules and nutritional interventions. Finally, the review addresses the significance of the gut-to-brain axis in mediating the effects of bioactive lipids on α-synuclein pathology and discusses the role of altered gut lipid metabolism and microbiota composition in neuroinflammation and neurodegeneration. The present review aims to underscore the potential of targeting α-synuclein-lipid interactions as a multifaceted approach for the detection and treatment of neurodegenerative and neuroinflammatory diseases.

Epidemiology of Parkinson's Disease: An Update

PURPOSE OF REVIEW

In recent decades, epidemiological understanding of Parkinson disease (PD) has evolved significantly. Major discoveries in genetics and large epidemiological investigations have provided a better understanding of the genetic, behavioral, and environmental factors that play a role in the pathogenesis and progression of PD. In this review, we provide an epidemiological update of PD with a particular focus on advances in the last five years of published literature.

RECENT FINDINGS

We include an overview of PD pathophysiology, followed by a detailed discussion of the known distribution of disease and varied determinants of disease. We describe investigations of risk factors for PD, and provide a critical summary of current knowledge, knowledge gaps, and both clinical and research implications. We emphasize the need to characterize the epidemiology of the disease in diverse populations. Despite increasing understanding of PD epidemiology, recent paradigm shifts in the conceptualization of PD as a biological entity will also impact epidemiological research moving forward and guide further work in this field.

Soluble LRP-1 in Parkinson's disease: clues for paradoxical effects

Background: Low density lipoprotein receptor-related protein-1 (LRP-1) is highly expressed in the central nervous system and plays a role in neurodegenerative disorders. The available data on this subject-matter seem to support the presence of a correlation between LRP-1 levels and abnormal aggregation of a plurality of proteins, including tau, amyloid, and α‑synuclein. Understanding the molecular mechanisms underlying Parkinson's disease (PD) is critical for development of new therapies.

Aim: To investigate serum soluble LRP-1 (sLRP-1) concentrations in patients with PD and explored their potential role as a biomarker in diagnosis and prognosis of disease.

Methods: Based on well-defined inclusion and exclusion criteria, we have included 133 PD patients and 45 healthy controls. The clinical severity was assessed using Hoehn Yahr and Unified PD Rating Scale (UPDRS). Following a fasting period, venous blood samples were taken, and centrifuged. Serum samples were stored until analysis. sLRP-1 was measured by ELISA assay.

Results: The median of serum sLRP-1 levels was higher in PD patients compared to that in healthy controls, but without reaching a statistical significance. There was a positive, but statistically insignificant, correlation between sLRP-1 levels and duration of disease. sLRP-1 levels had a significant correlation with UPDRS Parts I and IV. Patients with hypertension showed lower levels of sLRP-1.

Conclusion: The present study suggests that serum sLRP-1 concentrations are associated with the factors influencing prognosis of PD and disease severity. Further studies are needed to definitively determine whether or not sLRP-1 can be utilized as a diagnostic and prognostic biomarker for PD.

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.

The effects of cholesterol and statins on Parkinson's neuropathology: a narrative review

Parkinson disease (PD) is chronic and progressive neurodegenerative disease of the brain characterized by motor symptoms including tremors, rigidity, postural instability, and bradykinesia. PD neuropathology is due to the progressive degeneration of dopaminergic neurons in the substantia nigra and accumulation of Lewy bodies in the survival neurons. The brain contains a largest amount of cholesterol which is mainly synthesized from astrocytes and glial cells. Cholesterol is intricate in the pathogenesis of PD and may be beneficial or deleterious. Therefore, there are controversial points concerning the role of cholesterol in PD neuropathology. In addition, cholesterol-lowering agents' statins can affect brain cholesterol. Different studies highlighted that statins, via inhibition of brain HMG-CoA, can affect neuronal integrity through suppression of neuronal cholesterol, which regulates synaptic plasticity and neurotransmitter release. Furthermore, statins affect the development and progression of different neurodegenerative diseases in bidirectional ways that could be beneficial or detrimental. Therefore, the objective of the present review was to clarify the double-sward effects of cholesterol and statins on PD neuropathology.

Causal association of blood lipids with all-cause and cause-specific mortality risk: a Mendelian randomization study

Dyslipidemia has long been implicated in elevating mortality risk; yet, the precise associations between lipid traits and mortality remained undisclosed. Our study aimed to explore the causal effects of lipid traits on both all-cause and cause-specific mortality. One-sample Mendelian randomization (MR) with linear and nonlinear assumptions was conducted in a cohort of 407,951 European participants from the UK Biobank. Six lipid traits, consisting of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), and lipoprotein(a), were included to investigate the causal associations with mortality. Two-sample MR was performed to replicate the association between each lipid trait and all-cause mortality. Univariable MR results showed that genetically predicted higher ApoA1 was significantly associated with a decreased all-cause mortality risk (HR[95% CI]:0.93 [0.89-0.97], P value = 0.001), which was validated by the two-sample MR analysis. Higher lipoprotein(a) was associated with an increased risk of all-cause mortality (1.03 [1.01-1.04], P value = 0.002). Multivariable MR confirmed the direct causal effects of ApoA1 and lipoprotein(a) on all-cause mortality. Meanwhile, nonlinear MR found no evidence for nonlinearity between lipids and all-cause mortality. Our examination into cause-specific mortality revealed a suggestive inverse association between ApoA1 and cancer mortality, a significant positive association between lipoprotein(a) and cardiovascular disease mortality, and a suggestive positive association between lipoprotein(a) and digestive disease mortality. High LDL-C was associated with an increased risk of cardiovascular disease mortality but a decreased risk of neurodegenerative disease mortality. The findings suggest that implementing interventions to raise ApoA1 and decrease lipoprotein(a) levels may improve overall health outcomes and mitigate cancer and digestive disease mortality.

Plasma proteomic profiles predict future dementia in healthy adults

The advent of proteomics offers an unprecedented opportunity to predict dementia onset. We examined this in data from 52,645 adults without dementia in the UK Biobank, with 1,417 incident cases and a follow-up time of 14.1 years. Of 1,463 plasma proteins, GFAP, NEFL, GDF15 and LTBP2 consistently associated most with incident all-cause dementia (ACD), Alzheimer's disease (AD) and vascular dementia (VaD), and ranked high in protein importance ordering. Combining GFAP (or GDF15) with demographics produced desirable predictions for ACD (area under the curve (AUC) = 0.891) and AD (AUC = 0.872) (or VaD (AUC = 0.912)). This was also true when predicting over 10-year ACD, AD and VaD. Individuals with higher GFAP levels were 2.32 times more likely to develop dementia. Notably, GFAP and LTBP2 were highly specific for dementia prediction. GFAP and NEFL began to change at least 10 years before dementia diagnosis. Our findings strongly highlight GFAP as an optimal biomarker for dementia prediction, even more than 10 years before the diagnosis, with implications for screening people at high risk for dementia and for early intervention.

The potential role of cholesterol in Parkinson's disease neuropathology: perpetrator or victim

Parkinson's disease (PD) is a neurodegenerative disease characterized by deposition of α-synuclein and aggregation of Lewy bodies. Cholesterol is involved with PD neuropathology in bidirectional ways that could be protective or harmful. Thus, the objective of the present review was to verify the potential role of cholesterol in PD neuropathology. Deregulation of ion channels and receptors induced by cholesterol alteration suggests a possible mechanism for the neuroprotective effects of cholesterol against PD development. However, high serum cholesterol level increases PD risk indirectly by 27-hydroxycholesterol which induces oxidative stress, inflammation, and apoptosis. Besides, hypercholesterolemia triggers the accumulation of cholesterol in macrophages and immune cells leading to the release of pro-inflammatory cytokines with progression of neuroinflammation subsequently. Additionally, cholesterol increases aggregation of α-synuclein and induces degeneration of dopaminergic neurons (DN) in the substantia nigra (SN). Hypercholesterolemia may lead to cellular Ca2+ overload causing synaptic and the development of neurodegeneration. In conclusion, cholesterol has bidirectional effects on PD neuropathology and might be protective or harmful.

Recent research progress on metabolic syndrome and risk of Parkinson's disease

Parkinson's disease (PD) is one of the most widespread neurodegenerative diseases. PD is associated with progressive loss of substantia nigra dopaminergic neurons, including various motor symptoms (e.g., bradykinesia, rigidity, and resting tremor), as well as non-motor symptoms (e.g., cognitive impairment, constipation, fatigue, sleep disturbance, and depression). PD involves multiple biological processes, including mitochondrial or lysosomal dysfunction, oxidative stress, insulin resistance, and neuroinflammation. Metabolic syndrome (MetS), a collection of numerous connected cerebral cardiovascular conditions, is a common and growing public health problem associated with many chronic diseases worldwide. MetS components include central/abdominal obesity, systemic hypertension, diabetes, and atherogenic dyslipidemia. MetS and PD share multiple pathophysiological processes, including insulin resistance, oxidative stress, and chronic inflammation. In recent years, MetS has been linked to an increased risk of PD, according to studies; however, the specific mechanism remains unclear. Researchers also found that some related metabolic therapies are potential therapeutic strategies to prevent and improve PD. This article reviews the epidemiological relationship between components of MetS and the risk of PD and discusses the potentially relevant mechanisms and recent progress of MetS as a risk factor for PD. Furthermore, we conclude that MetS-related therapies are beneficial for the prevention and treatment of PD.

Pros and cons for statins use and risk of Parkinson's disease: An updated perspective

Parkinson's disease (PD) is the second most frequent neurodegenerative brain disease (NBD) after Alzheimer's disease (AD). Statins are the most common lipid-lowering agents used in the management of dyslipidemia and the prevention of primary and secondary cardiovascular diseases (CVD) events. In addition, there is a controversial point regarding the role of serum lipids in the pathogenesis of PD. In this bargain, as statins reduce serum cholesterol so they affect the PD neuropathology in bidirectional ways either protective or harmful. Statins are not used in the management of PD, but they are frequently used in the cardiovascular disorders commonly associated with PD in the elderly population. Therefore, the use of statins in that population may affect PD outcomes. Concerning the potential role of statins on PD neuropathology, there are conflicts and controversies either protective against the development of PD or harmful by increasing the risk for the development of PD. Therefore, this review aimed to clarify the precise role of statins in PD regarding the pros and cons from published studies. Many studies suggest a protective role of statins against PD risk through the modulation of inflammatory and lysosomal signaling pathways. Nevertheless, other observations suggest that statin therapy may increase PD risk by diverse mechanisms including reduction of CoQ10. In conclusion, there are strong controversies regarding the protective role of statins in PD neuropathology. Therefore, retrospective and prospective studies are necessary in this regard.

Deep brain stimulation improves central nervous system inflammation in Parkinson's disease: Evidence and perspectives

BACKGROUND

In Parkinson's disease (PD), inflammation may lead to the degeneration of dopaminergic (DAergic) neurons. Previous studies showed that inflammatory mediators mainly contributed to this phenomenon. On the other hand, invasive neuromodulation methods such as deep brain stimulation (DBS) have better therapeutic effects for PD. One possibility is that DBS improves PD by influencing inflammation. Therefore, we further explored the mechanisms underlying inflammatory mediators and DBS in the pathogenesis of PD.

METHODS

We measured serum levels of two inflammatory markers, namely RANTES (regulated on activation, normal T cell expressed and secreted) and tumor necrosis factor-alpha (TNF-α), using Luminex assays in 109 preoperative DBS PD patients, 49 postoperative DBS PD patients, and 113 age- and sex-matched controls. The plasma protein data of the different groups were then statistically analyzed.

RESULTS

RANTES (p < 0.001) and TNF-α (p = 0.005) levels differed significantly between the three groups. A strong and significant correlation between RANTES levels and Hoehn-Yahr (H-Y) stage was observed in preoperative PD patients (r_s  = 0.567, p < 0.001). Significant correlations between RANTES levels and Unified Parkinson's Disease Rating Scale III (UPDRS III) score (r_s1  = 0.644, p = 0.033 and r_s2  = 0.620, p = 0.042) were observed in matched patients. No correlation was observed for TNF-α levels.

CONCLUSION

The results of this study indicate that PD patients have a persistent inflammatory profile, possibly via recruitment of activated monocytes, macrophages, and T lymphocytes to the central nervous system (CNS). DBS was shown to have a significant therapeutic effect on PD, which may arise by improving the inflammatory environment of the central nervous system.

Alternations of Lipoprotein Profiles in the Plasma as Biomarkers of Huntington's Disease

Alterations in lipid composition and disturbed lipoprotein metabolism are involved in the pathomechanism of Huntington's disease (HD). Here, we measured 112 lipoprotein subfractions and components in the plasma of 20 normal controls, 24 symptomatic (sympHD) and 9 presymptomatic (preHD) HD patients. Significant changes were found in 30 lipoprotein subfractions and components in all HD patients. Plasma levels of total cholesterol (CH), apolipoprotein (Apo)B, ApoB-particle number (PN), and components of low-density lipoprotein (LDL) were lower in preHD and sympHD patients. Components of LDL4, LDL5, LDL6 and high-density lipoprotein (HDL)4 demonstrated lower levels in preHD and sympHD patients compared with controls. Components in LDL3 displayed lower levels in sympHD compared with the controls, whereas components in very low-density lipoprotein (VLDL)5 were higher in sympHD patients compared to the controls. The levels of components in HDL4 and VLDL5 demonstrated correlation with the scores of motor assessment, independence scale or functional capacity of Unified Huntington's Disease Rating Scale. These findings indicate the potential of components of VLDL5, LDL3, LDL4, LDL5 and HDL4 to serve as the biomarkers for HD diagnosis and disease progression, and demonstrate substantial evidence of the involvement of lipids and apolipoproteins in HD pathogenesis.

The Effect of Blood Lipids, Type 2 Diabetes, and Body Mass Index on Parkinson's Disease: A Korean Mendelian Randomization Study

OBJECTIVE

Associations between various metabolic conditions and Parkinson's disease (PD) have been previously identified in epidemiological studies. We aimed to investigate the causal effect of lipid levels, type 2 diabetes mellitus (T2DM), and body mass index (BMI) on PD in a Korean population via Mendelian randomization (MR).

METHODS

Two-sample MR analyses were performed with inverse-variance weighted (IVW), weighted median, and MR-Egger regression approaches. We identified genetic variants associated with lipid concentrations, T2DM, and BMI in publicly available summary statistics, which were either collected from genome-wide association studies (GWASs) or from meta-analyses of GWAS that targeted only Korean individuals or East Asian individuals, including Korean individuals. The outcome dataset was a GWAS on PD performed in a Korean population.

RESULTS

From previous GWASs and meta-analyses, we selected single nucleotide polymorphisms as the instrumental variables. Variants associated with serum levels of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides, as well as with T2DM and BMI, were selected (n = 11, 19, 17, 89, and 9, respectively). There were no statistically significant causal associations observed between the five exposures and PD using either the IVW, weighted median, or MR-Egger methods (p-values of the IVW method: 0.332, 0.610, 0.634, 0.275, and 0.860, respectively).

CONCLUSION

This study does not support a clinically relevant causal effect of lipid levels, T2DM, and BMI on PD risk in a Korean population.

Plasma lipid profiles and homocysteine levels in anti-N-methyl-D-aspartate receptor encephalitis

Introduction

We aimed to investigate whether lipid profiles and homocysteine levels in patients with anti-N-methyl-D-aspartate receptor encephalitis are related to clinical presentation and prognosis, which may contribute to further research on the pathogenesis and treatment of this disease.

Methods

This study included a total of 43 patients with anti-N-methyl-D-aspartate receptor encephalitis and 43 sex-age-matched healthy controls. Baseline demography, clinical data, patient outcomes, and ancillary examination results were recorded. Patients were followed up every 2-3 months during the first year. The modified Rankin Scale score was used to evaluate the therapeutic effect and clinical outcome.

Results

Among the 43 patients included in this study, 55.81% were male, the mean age of onset was 27 years old, and the median modified Rankin Scale score on admission was 3.0. Apolipoprotein A-1 was significantly lower in patients with anti-N-methyl-D-aspartate receptor encephalitis compared with healthy controls (p = 0.004). Compared with healthy controls, homocysteine (p = 0.002), apolipoprotein B (p = 0.004), Lpa (p = 0.045), and apolipoprotein B/apolipoprotein A-1 (p = 0.001) were significantly increased in patients with anti-N-methyl-D-aspartate receptor encephalitis. According to the modified Rankin Scale scores, 6 months after discharge, 72.09% of patients had a good prognosis and 27.91% had a poor prognosis. In the good prognosis group, age (p = 0.031), lipoprotein a (p = 0.023), apolipoprotein A-1 (p = 0.027) at baseline, and the modified Rankin Scale score on admission (p = 0.019) were significantly higher than those in the poor prognosis group.

Conclusion

This study suggests the possibility that serum lipid profile and homocysteine play an important role in the pathogenesis of anti-N-methyl-D-aspartate receptor encephalitis, providing support for lipid-lowering treatment of anti-N-methyl-D-aspartate receptor encephalitis patients.

Association between serum lipid levels over time and risk of Parkinson's disease

The role of serum lipids in Parkinson's disease (PD) remains controversial. We aimed to evaluate the association between time-varying serum lipid levels and the risk of PD. This study included an assessment of the complete lipid profiles of 200,454 individuals from the 2002-2019 Korean National Health Insurance Health Screening Cohort. Time-dependent Cox proportional hazard regression models were used to evaluate the association between serum lipid levels over time and the risk of PD. Individuals in the lowest tertile of total cholesterol and low-density lipoprotein cholesterol had a 1.17 times [hazard ratio (HR) 1.17; 95% confidence interval (CI) 1.04-1.31] and 1.19 times (HR 1.19; 95% CI 1.06-1.34) higher risk of PD than those in middle tertile, respectively. Individuals in the highest high-density lipoprotein cholesterol tertile had a 0.89 times (HR 0.89; 95% CI 0.79-1.00) lower risk of PD than those in middle tertile, but the association was less robust in sensitivity analyses. Serum triglyceride levels were not related to the risk of PD. Our results suggest that the serum total and low-density lipoprotein cholesterol levels over time are inversely associated with the risk of PD. Further research is warranted to confirm these findings and reveal the underlying mechanisms.

Linking the Low-Density Lipoprotein-Cholesterol (LDL) Level to Arsenic Acid, Dimethylarsinic, and Monomethylarsonic: Results from a National Population-Based Study from the NHANES, 2003–2020

Arsenic (As) contamination is a global public health problem. Elevated total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) are risk factors for cardiovascular diseases, but data on the association of urinary arsenic species’ level and LDL-C are limited. We performed an association analysis based on urinary arsenic species and blood TC and LDL-C in US adults. Methods: Urinary arsenic, arsenic acid (AA), dimethylarsinic (DMA), monomethylarsonic (MMA), TC, LDL-C, and other key covariates were obtained from the available National Health and Nutrition Examination Survey (NHANES) data from 2003 to 2020. Multiple linear regression analysis and generalized linear model are used to analyze linear and nonlinear relationships, respectively. Results: In total, 6633 adults aged 20 years were enrolled into the analysis. The median total urinary arsenic level was 7.86 µg/L. A positive association of urinary arsenic concentration quartiles was observed with TC (β: 2.42 95% CI 1.48, 3.36). The OR for TC of participants in the 80th versus 20th percentiles of urinary total arsenic was 1.34 (95% CI 1.13, 1.59). The OR for LDL-C of participants in the 80th versus 20th percentiles of urinary total arsenic was 1.36 (95% CI 1.15, 1.62). For speciated arsenics analysis, the OR for arsenic acid and TC was 1.35 (95% CI 1.02, 1.79), whereas the OR for DMA and LDL-L was 1.20 (95% CI 1.03, 1.41), and the OR for MMA and LDL-L was 1.30 (95% CI 1.11, 1.52). Conclusions: Urinary arsenic and arsenic species were positively associated with increased LDL-C concentration. Prevention of exposure to arsenic and arsenic species maybe helpful for the control of TC and LDL-C level in adults.

Elevated ApoB/ApoA-I ratio is associated with acute anti-N-Methyl-D-aspartate receptor encephalitis, but not disease outcomes

Objective

The purpose of the present study is to clarify the relationship between the apolipoprotein B100/apolipoprotein A-I (ApoB/ApoA-I) ratio and anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis.

Methods

A total of 71 patients with anti-NMDAR encephalitis were included in this study, and their ApoB/ApoA-I ratios in baseline and follow-up were retrospectively analyzed.

Results

The ApoB/ApoA-I ratio was closely correlated with the baseline-modified Rankin scale (mRS) score of >3 in patients with anti-NMDAR encephalitis. A subgroup analysis showed obvious differences between the high and low ApoB/ApoA-I ratio groups. The ApoB/ApoA-I ratio was positively correlated with intensive care unit (ICU) treatment, length of hospital stay, baseline mRS score, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). The ratios of the high and low ApoB/ApoA-I groups both improved in the follow-up.

Conclusion

The increased ApoB/ApoA-I ratio is associated with acute anti-NMDAR encephalitis, but not disease outcomes. Serum ApoB/ApoA-I ratio was related to inflammation and immunity in peripheral blood. The findings might provide a new idea for further exploration of the pathogenesis and treatment of anti-NMDAR encephalitis.

Lower serum triglyceride levels linked to more severe motor performance in Parkinson’s disease

Introduction

Emerging evidence has suggested that lipid metabolism is correlated with Parkinson’s disease (PD) onset and progression. However, the effect of lipid metabolism on motor performance in PD patients is still unknown. This study estimated the association between lipid profiles and the severity of motor performance in PD.

Methods

This cross-sectional study enrolled 279 idiopathic PD patients from the Department of Neurology of Beijing Tiantan Hospital from May 2016 to August 2018. Serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (Apo-A1), and apolipoprotein B (Apo-B) levels were detected in fast serum samples. Motor performance was assessed by Movement Disorder Society-Unified Parkinson’s Disease Rating Scale part III (MDS-UPDRS III) total scores and subscores in these patients. The associations of lipid profiles with motor performance were analyzed using multivariable linear regression models.

Results

Compared to males, females with PD exhibited significantly higher serum TC, LDL-C, HDL-C, Apo-A1, and Apo-B levels. When accounting for covariates, lower serum TG levels were significantly associated with higher MDS-UPDRS III total scores and gait/postural instability subscores. Additionally, the univariate linear regression model showed that in males with PD, serum HDL-C or Apo-A1 levels were significantly associated with tremor subscores.

Conclusion

Lower serum TG levels were associated with more severe motor performance in patients with PD and TG may be a potential predictive biomarker for motor performance in PD patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-022-06113-9.

Comparison of risk factors for Parkinson’s disease, coronary events and ischemic stroke

Parkinson’s disease (PD) and cardiovascular disease share many important risk factors, but some associations differ. However, there are no studies that have compared their shared and specific risk factors. The present study aimed to compare risk factors for PD, coronary events, or ischemic stroke. We prospectively analyzed data from 26,210 participants with lifestyle factors aged 45–73 years enrolled between 1991 and 1996. The Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of PD, coronary events, or ischemic stroke in relation to each factor. A modified Lunn-McNeil competing risk analysis was performed to compare the HR strength of the three outcomes. A total of 486 incident PD cases, 3288 coronary events cases and 2,972 ischemic stroke cases occurred during a mean follow-up of 21 years. In multivariable models, age (per additional year: HR = 1.08; 95% CI: 1.06, 1.09), diabetes (HR = 1.52; 95% CI: 1.02, 2.26), neutrophil–lymphocyte ratio (per SD increase: HR = 1.09; 95% CI: 1.00, 1.19), and fasting blood glucose (per SD increase: HR = 1.18; 95% CI: 1.03, 1.36) are the risk factors for PD, whereas female sex (HR = 0.54; 95% CI: 0.43, 0.67), smoking (current smoker [HR = 0.57; 95% CI: 0.43, 0.74] and former smoker [HR = 0.81; 95% CI: 0.66, 0.99]), HDL (per SD increase: HR = 0.74; 95% CI: 0.57, 0.95), and LDL (per SD increase: HR = 0.77; 95% CI: 0.61, 0.96) are the protective factors. A comparison of risk factors for PD, coronary events, and ischemic stroke showed the three outcomes had concordant and discordant risk factors. Our results indicated the risk factor profiles for PD, coronary events, or ischemic stroke had many similarities, but also significant differences.

Apolipoprotein A-I mimetic peptides (ApoAI MP) improve oxidative stress and inflammatory responses in Parkinson’s disease mice

Purpose: Parkinson’s disease (PD) is closely associated with oxidative stress and inflammatory situation. Apolipoprotein A-I mimetic peptides (ApoAI MP) have antioxidant and anti-inflammatory properties. We aimed to study the therapeutic effect of ApoAI MP on PD mice, and to explore the related mechanisms.

Methods: PD mice were induced by using 1-methyl-4-phenyl-1,2,3,6-tetrathydropyridine (MPTP). The model mice were treated with different concentrations of ApoAI MP. The open-field behavioral test assesses the total distance moved, the rest time, and the number of crossings and Rota-rod was used to evaluate motor coordination. Oxidative stress was identified by measuring the levels of superoxide dismutase (SOD), catalase (CAT), glutathionperoxidase (GSH-Px), malondialdehyde, ROS and H2O2. Inflammatory situation was analyzed by measuring the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Meanwhile, the scavenging activities of ApoAI MP for ABTS, DPPH, hydroxyl radical and superoxide anion, and the effects of the peptide on neurotransmitters were evaluated.

Results: PD model establishment increased oxidative stress and inflammatory status by increasing the concentrations of ROS and H2O2 production, and the levels of TNF-α, IL-1β and IL-6 (p &lt; 0.05). ApoAI MP intervention improved PD symptoms by reducing the total moved distance and the number of passes (p &lt; 0.01), and the falling times from Rota-rod, and increasing rest time (p &lt; 0.05). ApoAI MP increased antioxidant properties by increasing the activities of SOD, CAT and GSH-Px, and reducing MDA concentration (p &lt; 0.05). ApoAI MP addition reduced oxidative stress by scavenging ABTS, DPPH, hydroxyl radicals and superoxide anion and reducing the concentrations of ROS and H2O2 production (p &lt; 0.05). ApoAI MP treatment increased anti-inflammatory capacities by reducing the concentrations of TNF-α, IL-1β and IL-6 (p &lt; 0.05). HPLC analysis showed that the peptide treatment improved neurotransmitters.

Conclusion: ApoAI MP can improve the behavioral performance of PD mice by improving antioxidant and anti-inflammatory capacities.

Systematic review of Mendelian randomization studies on Parkinson's disease

Background

Parkinson's disease (PD) is known to be associated with non-genetic factors. To infer causality, Mendelian randomization (MR) studies are increasingly used. Here, genetic variants are used as instrumental variables for the risk factor but have no direct effect on PD themselves.

Methods

We performed a systematic literature review on MR studies for PD. Studies were identified searching the PubMed database. Upon data extraction, we evaluated the methodological quality and summarized the evidence.

Results

Twelve articles were included. Most studies showed "good" methodological quality, but most did not report proper power estimations. Twelve analyses yielded nominally significant effects.

Conclusions

Our systematic review shows that most MR studies were well performed and allow to identify causal exposures, which may inform further studies on the prevention and early intervention of PD.

Lipid level alteration in human and cellular models of alpha synuclein mutations

Lipid profiles in biological fluids from patients with Parkinson's disease (PD) are increasingly investigated in search of biomarkers. However, the lipid profiles in genetic PD remain to be determined, a gap of knowledge of particular interest in PD associated with mutant α-synuclein (SNCA), given the known relationship between this protein and lipids. The objective of this research is to identify serum lipid composition from SNCA A53T mutation carriers and to compare these alterations to those found in cells and transgenic mice carrying the same genetic mutation. We conducted an unbiased lipidomic analysis of 530 lipid species from 34 lipid classes in serum of 30 participants with SNCA mutation with and without PD and 30 healthy controls. The primary analysis was done between 22 PD patients with SNCA+ (SNCA+/PD+) and 30 controls using machine-learning algorithms and traditional statistics. We also analyzed the lipid composition of human clonal-cell lines and tissue from transgenic mice overexpressing the same SNCA mutation. We identified specific lipid classes that best discriminate between SNCA+/PD+ patients and healthy controls and found certain lipid species, mainly from the glycerophosphatidylcholine and triradylglycerol classes, that are most contributory to this discrimination. Most of these alterations were also present in human derived cells and transgenic mice carrying the same mutation. Our combination of lipidomic and machine learning analyses revealed alterations in glycerophosphatidylcholine and triradylglycerol in sera from PD patients as well as cells and tissues expressing mutant α-Syn. Further investigations are needed to establish the pathogenic significance of these α-Syn-associated lipid changes.

HDL Accessory Proteins in Parkinson’s Disease—Focusing on Clusterin (Apolipoprotein J) in Regard to Its Involvement in Pathology and Diagnostics—A Review

Parkinson’s disease (PD)—a neurodegenerative disorder (NDD) characterized by progressive destruction of dopaminergic neurons within the substantia nigra of the brain—is associated with the formation of Lewy bodies containing mainly α-synuclein. HDL-related proteins such as paraoxonase 1 and apolipoproteins A1, E, D, and J are implicated in NDDs, including PD. Apolipoprotein J (ApoJ, clusterin) is a ubiquitous, multifunctional protein; besides its engagement in lipid transport, it modulates a variety of other processes such as immune system functionality and cellular death signaling. Furthermore, being an extracellular chaperone, ApoJ interacts with proteins associated with NDD pathogenesis (amyloid β, tau, and α-synuclein), thus modulating their properties. In this review, the association of clusterin with PD is delineated, with respect to its putative involvement in the pathological mechanism and its application in PD prognosis/diagnosis.

Emerging role of HDL in brain cholesterol metabolism and neurodegenerative disorders

High-density lipoproteins (HDLs play a key role in cholesterol homeostasis maintenance in the central nervous system (CNS), by carrying newly synthesized cholesterol from astrocytes to neurons, to support their lipid-related physiological functions. As occurs for plasma HDLs, brain lipoproteins are assembled through the activity of membrane cholesterol transporters, undergo remodeling mediated by specific enzymes and transport proteins, and finally deliver cholesterol to neurons by a receptor-mediated internalization process. A growing number of evidences indicates a strong association between alterations of CNS cholesterol homeostasis and neurodegenerative disorders, in particular Alzheimer's disease (AD), and a possible role in this relationship may be played by defects in brain HDL metabolism. In the present review, we summarize and critically examine the current state of knowledge on major modifications of HDL and HDL-mediated brain cholesterol transport in AD, by taking into consideration the individual steps of this process. We also describe potential and encouraging HDL-based therapies that could represent new therapeutic strategies for AD treatment. Finally, we revise the main plasma and brain HDL modifications in other neurodegenerative disorders including Parkinson's disease (PD), Huntington's disease (HD), and frontotemporal dementia (FTD).

Lipid-lowering drug targets and Parkinson's disease: A sex-specific Mendelian randomization study

Parkinson's disease (PD) affects millions of individuals worldwide, and it is the second most common late-onset neurodegenerative disorder. There is no cure and current treatments only alleviate symptoms. Modifiable risk factors have been explored as possible options for decreasing risk or developing drug targets to treat PD, including low-density lipoprotein cholesterol (LDL-C). There is evidence of sex differences for cholesterol levels as well as for PD risk. Genetic datasets of increasing size are permitting association analyses with increased power, including sex-stratified analyses. These association results empower Mendelian randomization (MR) studies, which, given certain assumptions, test whether there is a causal relationship between the risk factor and the outcome using genetic instruments. Sex-specific causal inference approaches could highlight sex-specific effects that may otherwise be masked by sex-agnostic approaches. We conducted a sex-specific two-sample cis-MR analysis based on genetic variants in LDL-C target encoding genes to assess the impact of lipid-lowering drug targets on PD risk. To complement the cis-MR analysis, we also conducted a sex-specific standard MR analysis (using genome-wide independent variants). We did not find evidence of a causal relationship between LDL-C levels and PD risk in females [OR (95% CI) = 1.01 (0.60, 1.69), IVW random-effects] or males [OR (95% CI) = 0.93 (0.55, 1.56)]. The sex-specific standard MR analysis also supported this conclusion. We encourage future work assessing sex-specific effects using causal inference techniques to better understand factors that may contribute to complex disease risk differently between the sexes.

Identification of blood-based biomarkers for diagnosis and prognosis of Parkinson's disease: A systematic review of proteomics studies

Parkinson's Disease (PD), a neurodegenerative disorder, is characterised by the loss of motor function and dopamine neurons. Therapeutic avenues remain a challenge due to lack of accuracy in early diagnosis, monitoring of disease progression and limited therapeutic options. Proteomic platforms have been utilised to discover biomarkers for numerous diseases, a tool that may benefit the diagnosis and monitoring of disease progression in PD patients. Therefore, this systematic review focuses on analysing blood-based candidate biomarkers (CB) identified via proteomics platforms for PD. This study systematically reviewed articles across six databases (EMBASE, Cochrane, Ovid Medline, Scopus, Science Direct and PubMed) published between 2010 and 2020. Of the 504 articles identified, 12 controlled-PD studies were selected for further analysis. A total of 115 candidate biomarkers (CB) were identified across selected 12-controlled studies, of which 23 CB were found to be replicable in more than two cohorts. Using the PANTHER Go-Slim classification system and STRING network, the gene function and protein interactions between biomarkers were analysed. Our analysis highlights Apolipoprotein A-I (ApoA-I), which is essential in lipid metabolism, oxidative stress, and neuroprotection demonstrates high replicability across five cohorts with consistent downregulation across four cohorts. Since ApoA-I was highly replicable across blood fractions, proteomic platforms and continents, its relationship with cholesterol, statin and oxidative stress as PD biomarker, its role in the pathogenesis of PD is discussed in this paper. The present study identified ApoA-I as a potential biomarker via proteomics analysis of PD for the early diagnosis and prediction of disease progression.

Lipidomics Reveals Dysregulated Glycerophospholipid Metabolism in the Corpus Striatum of Mice Treated with Cefepime

Cefepime exhibits a broad spectrum of antimicrobial activity and thus is a widely used treatment for severe bacterial infections. Adverse effects on the central nervous system (CNS) have been reported in patients treated with cefepime. Current explanation for the adverse neurobehavioral effect of cefepime is mainly attributed to its ability to cross the blood-brain barrier and competitively bind to the GABAergic receptor; however, the underlying mechanism is largely unknown. In this study, mice were intraperitoneally administered 80 mg/kg cefepime for different periods, followed by neurobehavioral tests and a brain lipidomic analysis. LC/MS-MS-based metabolomics was used to investigate the effect of cefepime on the brain lipidomic profile and metabolic pathways. Repeated cefepime treatment time-dependently caused anxiety-like behaviors, which were accompanied by reduced locomotor activity in the open field test. Cefepime profoundly altered the lipid profile, acyl chain length, and unsaturation of fatty acids in the corpus striatum, and glycerophospholipids accounted for a large proportion of those significantly modified lipids. In addition, cefepime treatment caused obvious alteration in the lipid-enriched membrane structure, neurites, mitochondria, and synaptic vesicles of primary cultured striatal neurons; moreover, the spontaneous electrical activity of striatal neurons was significantly reduced. Collectively, cefepime reprograms glycerophospholipid metabolism in the corpus striatum, which may interfere with neuronal structure and activity, eventually leading to aberrant neurobehaviors in mice.

Clinical Association between Gout and Parkinson's Disease: A Nationwide Population-Based Cohort Study in Korea

Background and Objectives: This retrospective cohort study aimed to investigate the association between gout and Parkinson’s disease (PD) in Korea. Materials and Methods: Overall, 327,160 patients with gout and 327,160 age- and sex-matched controls were selected from the Korean National Health Insurance Service (NHIS) database. PD incidence was evaluated by reviewing NHIS records during the period from 2002 to 2019. Patients with a diagnosis of gout (International Classification of Diseases-10 (ICD-10), M10) who were prescribed medications for gout, including colchicine, allopurinol, febuxostat, and benzbromarone for at least 90 days were selected. Patients with PD who were assigned a diagnosis code (ICD-G20) and were registered in the rare incurable diseases (RID) system were extracted. Results: During follow-up, 912 patients with gout and 929 control participants developed PD. The incidence rate (IR) of overall PD (per 1000 person-years) was not significantly different between both groups (0.35 vs. 0.36 in gout and control groups, respectively). The incidence rate ratio (IRR) was 0.98 (95% CI: 0.89–1.07). The cumulative incidence of PD was not significantly different between the groups. No association between gout and PD was identified in univariate analysis (HR = 1.00, 95% CI: 0.91–1.10, p = 0.935). HR increased significantly with old age (HR = 92.08, 198, and 235.2 for 60–69 years, 70–79 years, and over 80 years, respectively), female sex (HR = 1.21, 95% CI: 1.07–1.37, p = 0.002), stroke (HR = 1.95, 95% CI: 1.76–2.16, p < 0.001), and hypertension (HR = 1.16, 95% CI: 1.01–1.34, p = 0.04). Dyslipidemia exhibited an inverse result for PD (HR = 0.6, 95% CI: 0.52–0.68, p < 0.001). Conclusions: This population-based study did not identify an association between gout and PD. Age, female sex, stroke, and hypertension were identified as independent risk factors for PD, and dyslipidemia demonstrated an inverse result for PD.

Blood Cholesterol Decreases as Parkinson's Disease Develops and Progresses

BACKGROUND

Literature shows an inverse association of circulating cholesterol level with the risk of Parkinson's disease (PD); this finding has important ramifications, but its interpretation has been debated.

OBJECTIVE

To longitudinally examine how blood total cholesterol changes during the development of PD.

METHODS

In the Health, Aging and Body Composition study (n = 3,053, 73.6±2.9 years), blood total cholesterol was measured at clinic visit years 1, 2, 4, 6, 8, 10, and 11. We first examined baseline cholesterol in relation to PD risk, adjusting for potential confounders and competing risk of death. Then, by contrasting the observed with expected cholesterol levels, we examined the trajectory of changes in total cholesterol before and after disease diagnosis.

RESULTS

Compared to the lowest tertile of baseline total cholesterol, the cumulative incidence ratio of PD and 95% confidence interval was 0.41 (0.20, 0.86) for the second tertile, and 0.69 (0.35, 1.35) for the third tertile. In the analysis that examined change of total cholesterol level before and after PD diagnosis, we found that its level began to decrease in the prodromal stage of PD and became statistically lower than the expected values ∼4 years before disease diagnosis (observed-expected difference, -6.68 mg/dL (95% confidence interval: -13.14, -0.22)). The decreasing trend persisted thereafter; by year-6 post-diagnosis, the difference increased to -13.59 mg/dL (95% confidence interval: -22.12, -5.06), although the linear trend did not reach statistical significance (p = 0.10).

CONCLUSION

Circulating total cholesterol began to decrease in the prodromal stage of PD, which may in part explain its reported inverse association with PD.

Serum lipid profile among sporadic and familial forms of Parkinson's disease

Brain cholesterol metabolism has been described as altered in Parkinson's disease (PD) patients. Serum lipid levels have been widely studied in PD with controversial results among different populations and age groups. The present study is aimed at determining if the serum lipid profile could be influenced by the genetic background of PD patients. We included 403 PD patients (342 sporadic PD patients, 30 GBA-associated PD patients, and 31 LRRK2-associated PD patients) and 654 healthy controls (HCs). Total cholesterol, HDL, LDL, and triglycerides were measured in peripheral blood. Analysis of covariance adjusting for sex and age (ANCOVA) and post hoc tests were applied to determine the differences within lipid profiles among the groups. Multivariate ANCOVA revealed significant differences among the groups within cholesterol and LDL levels. GBA-associated PD patients had significantly lower levels of total cholesterol and LDL compared to LRRK2-associated PD patients and HCs. The different serum cholesterol levels in GBA-associated PD might be related to diverse pathogenic mechanisms. Our results support the hypothesis of lipid metabolism disruption as one of the main PD pathogenic mechanisms in patients with GBA-associated PD. Further studies would be necessary to explore their clinical implications.

How low is safe? The frontier of very low (<30 mg/dL) LDL cholesterol

Low-density lipoprotein cholesterol (LDL-C) is a proven causative factor for developing atherosclerotic cardiovascular disease. Individuals with genetic conditions associated with lifelong very low LDL-C levels can be healthy. We now possess the pharmacological armamentarium (statins, ezetimibe, PCSK9 inhibitors) to reduce LDL-C to an unprecedented extent. Increasing numbers of patients are expected to achieve very low (<30 mg/dL) LDL-C. Cardiovascular event reduction increases log linearly in association with lowering LDL-C, without reaching any clear plateau even when very low LDL-C levels are achieved. It is still controversial whether lower LDL-C levels are associated with significant clinical adverse effects (e.g. new-onset diabetes mellitus or possibly haemorrhagic stroke) and long-term data are needed to address safety concerns. This review presents the familial conditions characterized by very low LDL-C, analyses trials with lipid-lowering agents where patients attained very low LDL-C, and summarizes the benefits and potential adverse effects associated with achieving very low LDL-C. Given the potential for cardiovascular benefit and short-term safe profile of very low LDL-C, it may be advantageous to attain such low levels in specific high-risk populations. Further studies are needed to compare the net clinical benefit of non-LDL-C-lowering interventions with very low LDL-C approaches, in addition to comparing the efficacy and safety of very low LDL-C levels vs. current recommended targets.

The disturbance of lipid metabolism is correlated with neuropsychiatric symptoms in patients with Parkinson's disease

OBJECTIVE

We aimed to identify the detailed relationships between serum lipid levels and neuropsychiatric symptoms in patients with Parkinson's disease (PD).

METHODS

Consecutive PD patients and healthy controls were recruited and demographic data were collected. The disease stages of PD patients were assessed using Hoehn-Yahr scale while neuropsychiatric symptoms were determined using Hamilton depression rating scale (HAMD), Hamilton anxiety rating scale (HAMA), and mini-mental state examination scale. Fast serum samples were obtained and the serum levels of lipids were identified. Linear regression analyses and correlation analyses were performed to explore the relationships between serum lipid levels and neuropsychiatric symptoms.

RESULTS

The serum levels of triglyceride had significantly decreased while the levels of HDL-c and lipoprotein a had increased in PD patients. Linear regression analyses confirmed that the levels of triglyceride were mainly correlated with age and HAMA score, the levels of HDL-c were correlated with disease duration and gender, and the levels of lipoprotein a were correlated with HAMD score. Correlation analyses further confirmed that the levels of triglyceride were negatively correlated with HAMA score when the levels of lipoprotein a were negatively correlated with HAMD score.

CONCLUSIONS

Lipid metabolism is significantly correlated with neuropsychiatric disorders in PD patients.

Aerts J, Moratalla R. The Role of Cholesterol in α-Synuclein and Lewy Body Pathology in GBA1 Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disease where dopaminergic neurons in the substantia nigra are lost, resulting in a decrease in striatal dopamine and, consequently, motor control. Dopaminergic degeneration is associated with the appearance of Lewy bodies, which contain membrane structures and proteins, including α-synuclein (α-Syn), in surviving neurons. PD displays a multifactorial pathology and develops from interactions between multiple elements, such as age, environmental conditions, and genetics. Mutations in the GBA1 gene represent one of the major genetic risk factors for PD. This gene encodes an essential lysosomal enzyme called β-glucocerebrosidase (GCase), which is responsible for degrading the glycolipid glucocerebroside into glucose and ceramide. GCase can generate glucosylated cholesterol via transglucosylation and can also degrade the sterol glucoside. Although the molecular mechanisms that predispose an individual to neurodegeneration remain unknown, the role of cholesterol in PD pathology deserves consideration. Disturbed cellular cholesterol metabolism, as reflected by accumulation of lysosomal cholesterol in GBA1-associated PD cellular models, could contribute to changes in lipid rafts, which are necessary for synaptic localization and vesicle cycling and modulation of synaptic integrity. α-Syn has been implicated in the regulation of neuronal cholesterol, and cholesterol facilitates interactions between α-Syn oligomers. In this review, we integrate the results of previous studies and describe the cholesterol landscape in cellular homeostasis and neuronal function. We discuss its implication in α-Syn and Lewy body pathophysiological mechanisms underlying PD, focusing on the role of GCase and cholesterol. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Compared with the monocyte to high-density lipoprotein ratio (MHR) and the neutrophil to lymphocyte ratio (NLR), the neutrophil to high-density lipoprotein ratio (NHR) is more valuable for assessing the inflammatory process in Parkinson's disease

Background

The inflammatory response plays essential roles in the pathological process and prognosis of Parkinson’s disease (PD). This research investigated the predictive value of the neutrophil to high-density lipoprotein ratio (NHR), neutrophil to lymphocyte ratio (NLR), and monocyte to high-density lipoprotein ratio (MHR) for PD.

Methods

Patients with PD (n = 98) were divided into three groups according to disease duration: < 6 years (n = 55), 6–10 years (n = 29) and > 10 years (n = 14). Based on the classification system of Hoehn and Yahr, grades 1 ~ 2.5 were considered early-stage PD (n = 44), and grades 3 ~ 5 were considered advanced-stage PD (n = 54). In addition, healthy subjects (n = 98) matched to the above PD patients in the same period were selected as the control group. Differences in the NHR, NLR, MHR and other indicators among the groups were evaluated.

Results

Smoking, drinking, the neutrophil count and the NHR and NLR were remarkably greater and hypertension, index of body mass, the lymphocyte count, and the levels of cholesterol in total, triglycerides, lipoprotein cholesterol with low density and uric acid were sharply lower in the PD group compared with in the control group. Analysis of multifactor logistic regression indicated that the NHR (odds ratio (adjusted OR) = 1.576, 95% CI: 1.053 ~ 2.358, P = 0.027) and NLR (adjusted OR = 1.734, 95% CI: 1.046 ~ 2.876, P = 0.033) were factors of risk for PD, while the MHR was not significantly correlated with PD. The areas under the receiver operating characteristic (ROC) curve (AUCs) for the prediction of PD by the NHR and NLR were 0.654 (95% CI: 0.583 ~ 0.721, P = 0.0001) and 0.69 (95% CI: 0.62 ~ 0.754, P < 0.0001), respectively, and the optimal cutoff values were 1.848 × 10⁹/mmol and 2.62 × 10⁹/mmol. Spearman’s correlation analysis indicated that the NHR was correlated with the disease duration significantly negatively and that the MHR was positively correlated with disease severity.

Conclusions

In summary, the NHR not only has strong predictive value for PD but is also closely related to disease duration. The NHR may be a better prediction for the long-period clinical results in PD patients than the MHR and NLR.

Trial registration

Clinical medical reserach center project of Qinghai Province (2017-SF-L1).

Serum lipid profile of Parkinson's disease patients: A study from the Northwest of Iran

BACKGROUND

Parkinson's disease (PD) is defined as a long-lasting, neurological illness. Low levels of serum lipid fractions are related with a high risk of PD. Current investigation was designed to evaluate the concentration blood lipid fractions in patients suffering from PD and compared with healthy subjects.

METHODS

This case-control study was conducted from February 2016 to September 2018 in Tabriz University of Medical Sciences, Tabriz, Iran. The present investigation consisted of 75 persons who had PD and 75 normal people. The blood levels of lipid fractions were measured by concentrations of total cholesterol (TC), serum triglycerides (TG), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), and total cholesterol. The results were analyzed with SPSS software using Kolmogorov-Smirnov, chi-square, and student's t-test.

RESULTS

Serum level of TG was remarkably lower in patients with PD (111.92±8.75 mg/dL) compared with healthy subjects (123.64±9.97 mg/dL, P=0.008). Furthermore, we saw an important difference in the level of LDL-C (P=0.001) and TC (P=0.004) between the two groups. However, there was not any observed meaningful difference in the serum concentrations of HDL-C between the studied groups (P=0.135).

CONCLUSION

Our results showed that the serum concentration of TG, LDL-C, and TC are noticeably lower in the PD suffering patients. Further investigations are needed to provide comprehensive information on the participants' cognitive layout and subsequent actions.

Association of lipid levels with motor and cognitive function and decline in advanced Parkinson's disease in the Mark-PD study

OBJECTIVES

In prospective cohort studies different blood lipid fractions have been identified as risk factors of Parkinson's disease (PD). However, data relating lipoproteins to disease phenotypes and progression in advanced PD patients are sparse. Therefore, we assessed the most common lipoproteins in a case-control design and evaluated their associations with motor and cognitive function and decline in PD patients.

METHODS

Triglycerides, LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), and lipoprotein a (Lp(a)) were analyzed in 294 PD patients of the MARK-PD study cohort and 588 controls matched for age, sex and cardiovascular risk factors. In PD patients, motor (MDS-UPDRS III, Hoehn-Yahr stage) and cognitive function (MoCA) were examined. In a sub-cohort (n = 98 patients), baseline lipid levels were correlated with motor and cognitive disease progression during a follow-up period of 523 ± 199 days.

RESULTS

At baseline, HDL-C levels were lower in PD patients compared to matched controls after adjustment. We observed a very weak association of Lp(a) levels with UDPRS III scores. In cross-sectional analyses, no other lipid fraction revealed a significant and consistent association with motor or cognitive function. During follow-up, no lipid fraction level was associated with motor or cognitive progression.

CONCLUSION

In advanced PD, there is no strong and consistent association of lipid levels with motor or cognitive function and decline.

ApoPred: Identification of Apolipoproteins and Their Subfamilies With Multifarious Features

Apolipoprotein is a group of plasma proteins that are associated with a variety of diseases, such as hyperlipidemia, atherosclerosis, Alzheimer's disease, and diabetes. In order to investigate the function of apolipoproteins and to develop effective targets for related diseases, it is necessary to accurately identify and classify apolipoproteins. Although it is possible to identify apolipoproteins accurately through biochemical experiments, they are expensive and time-consuming. This work aims to establish a high-efficiency and high-accuracy prediction model for recognition of apolipoproteins and their subfamilies. We firstly constructed a high-quality benchmark dataset including 270 apolipoproteins and 535 non-apolipoproteins. Based on the dataset, pseudo-amino acid composition (PseAAC) and composition of k-spaced amino acid pairs (CKSAAP) were used as input vectors. To improve the prediction accuracy and eliminate redundant information, analysis of variance (ANOVA) was used to rank the features. And the incremental feature selection was utilized to obtain the best feature subset. Support vector machine (SVM) was proposed to construct the classification model, which could produce the accuracy of 97.27%, sensitivity of 96.30%, and specificity of 97.76% for discriminating apolipoprotein from non-apolipoprotein in 10-fold cross-validation. In addition, the same process was repeated to generate a new model for predicting apolipoprotein subfamilies. The new model could achieve an overall accuracy of 95.93% in 10-fold cross-validation. According to our proposed model, a convenient webserver called ApoPred was established, which can be freely accessed at http://tang-biolab.com/server/ApoPred/service.html. We expect that this work will contribute to apolipoprotein function research and drug development in relevant diseases.

Cardiovascular Risk Among Patients ≥65 Years of Age with Parkinson's Disease (From the National Inpatient Sample)

In this study, we aimed to investigate the relationship between Parkinson's disease (PD) and vascular disease and risk factors using a nationally representative sample. The National Inpatient Sample was queried for all patients aged ≥65 who were diagnosed with PD during the year 2016. Patients were identified using the International Classification of Diseases-Tenth Revision (ICD-10) diagnosis code: "G20." Each patient diagnosed with PD was frequency-matched to controls at a 1:4 ratio by age and gender. Study outcomes were hypertension, hyperlipidemia, diabetes mellitus, coronary artery disease, and stroke. Outcomes were modeled using logistic regression analysis and further validation was obtained using a propensity score-matched analysis. A total of 57,914 patients (weighted: 289,570) with PD were included. Most patients were of Caucasian race (80.8%). Females were 42.4% and the mean age was 79 years, standard error of the mean (0.03). PD correlated with lower odds for hyperlipidemia adjusted odd ratio (a-OR): 0.77 (95% confidence interval [CI]: 0.75 to 0.79) p <0.001, diabetes mellitus a-OR 0.73 (95% CI 0.71 to 0.75) p <0.001, hypertension a-OR 0.68 (95% CI: 0.67 to 0.70) p <0.001, coronary artery disease a-OR 0.64 (95% CI: 0.63 to 0.66) p <0.001 and higher odds for stroke a-OR: 1.27 (95% CI: 1.24 to 1.31) p <0.001. Following propensity score matching, identical findings were found. In conclusion, patients with PD have a distinct cardiovascular profile with higher rates of stroke and lower rates of coronary artery disease and vascular disease risk factors.

Evaluating Lipid-Lowering Drug Targets for Parkinson's Disease Prevention with Mendelian Randomization

Long‐term exposure to lipid‐lowering drugs might affect Parkinson's disease (PD) risk. We conducted Mendelian randomization analyses where genetic variants indexed expected effects of modulating lipid‐lowering drug targets on PD. Statin exposure was not predicted to increase PD risk, although results were not precise enough to support benefits for prevention clearly (odds ratio [OR] = 0.83; 95% confidence interval [CI] = 0.65, 1.07). Other target results were null, except for variants indicating Apolipoprotein‐A5 or Apolipoprotein‐C3 inhibition might confer protection. These findings suggest peripheral lipid variation may not have a prominent role in PD etiology, but some related drug targets could influence PD via alternate pathways. ANN NEUROL 2020;88:1043–1047

Metabolic syndrome does not influence the phenotype of LRRK2 and GBA related Parkinson's disease

In order toevaluate the influence of the metabolic syndrome (MS) (obesity, hypertension, elevated triglycerides, reduced levels of HDL cholesterol and glucose impairment) on the phenotype of LRRK2 and GBA Parkinson’s disease (PD), and on the prevalence of prodromal features among individuals at risk, we collected, laboratory test results, blood pressure, demographic, cognitive, motor, olfactory and affective information enabling the assessment of each component of MS and the construction of the MDS prodromal probability score. The number of metabolic components and their levels were compared between participants who were separated based on disease state and genetic status. One hundred and four idiopathic PD, 40 LRRK2-PD, 70 GBA-PD, 196 healthy non-carriers, 55 LRRK2-NMC and 97 GBA-NMC participated in this study. PD groups and non manifesting carriers (NMC) did not differ in the number of metabolic components (p = 0.101, p = 0.685, respectively). LRRK2-PD had higher levels of triglycerides (p = 0.015) and higher rates of prediabetes (p = 0.004), while LRRK2-NMC had higher triglyceride levels (p = 0.014). NMC with probability rates for prodromal PD above 50% had higher frequencies of hypertriglyceridemia and prediabetes (p < 0.005, p = 0.023 respectively). While elevated triglycerides and prediabetes were more frequent among LRRK2 carriers, MS does not seem to influence GBA and LRRK2-PD phenotype.

A systematic review and meta-analysis of serum cholesterol and triglyceride levels in patients with Parkinson's disease

Objectives

Numerous studies have reported that lipid metabolic abnormalities may play an important role in the development of Parkinson’s disease (PD), with mixed results. This meta-analysis aims to systematically assess the relationship between serum cholesterol or triglyceride and the PD risk and to further determine the role of dyslipidemia in potential predictive value.

Methods

This research systematically consulted and screened observational studies to evaluate the association of serum lipids with the risk of PD as of April 01, 2020 based on the inclusion and exclusion criteria. Two researchers screened and extracted the data independently. Then this article summarized the characteristics of all clinical studies and collected the corresponding data to perform pooled and sensitivity analyses. The meta-analysis was performed by using the RevMan 5.3 software after data extraction, quality assessment and analysis of publication bias.

Results

Twenty-one related studies (13 case-control and 8 cohort studies) were selected with a total of 980,180 subjects, including 11,188 PD patients. Meta-analysis showed that higher levels of serum triglyceride (S-TG) [standard mean different (SMD) = − 0.26 (95% confidence interval (CI): − 0.39 to − 0.13, p<0.00001), relative risk (RR) = 0.67 (95% CI: 0.60 to 0.75, p<0.00001)] could be considered as protective factors for the pathogenesis of PD. However, there was no significant association between serum high density lipoprotein cholesterol (S-HDL) and the risk of PD. Meanwhile, serum low density lipoprotein cholesterol (S-LDL) [SMD = -0.26 (95% CI: − 0.43 to − 0.07, p = 0.006), RR = 0.76 (95% CI: 0.59 to 0.97, p = 0.03)] and serum total cholesterol (S-TC) levels [SMD = -0.21 (95% CI: − 0.33 to − 0.10, p = 0.0002), RR = 0.86 (95% CI: 0.77 to 0.97, p = 0.01)] were negatively associated with PD risk.

Conclusions

This systematic review suggests that elevated serum levels of TG, LDL and TC may be protective factors for the pathogenesis of PD. Further longitudinal and well-designed prospective studies with a large sample size are needed to confirm the findings in this meta-analysis.

Contra-Directional Expression of Plasma Superoxide Dismutase with Lipoprotein Cholesterol and High-Sensitivity C-reactive Protein as Important Markers of Parkinson's Disease Severity

Aim: Oxidative stress and inflammation play critical roles in the neuropathogenesis of PD. We aimed to evaluate oxidative stress and inflammation status by measuring serum superoxide dismutase (SOD) with lipoprotein cholesterol and high-sensitivity C-reactive protein (hsCRP) respectively in PD patients, and explore their correlation with the disease severity.

Methods: We performed a cross-sectional study that included 204 PD patients and 204 age-matched healthy controls (HCs). Plasma levels of SOD, hsCRP, total cholesterol, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured. A series of neuropsychological assessments were performed to rate the severity of PD.

Results: The plasma levels of SOD (135.7 ± 20.14 vs. 147.2 ± 24.34, P < 0.0001), total cholesterol, HDL-C and LDL-C in PD were significantly lower than those in HCs; the hsCRP level was remarkably increased in PD compared to HC (2.766 ± 3.242 vs. 1.637 ± 1.597, P < 0.0001). The plasma SOD was negatively correlated with the hsCRP, while positively correlated with total cholesterol, HDL-C, and LDL-C in PD patients. The plasma SOD were negatively correlated with H&Y, total UPDRS, UPDRS (I), UPDRS (II), and UPDRS (III) scores, but positively correlated with MoCA and MMSE scores. Besides, hsCRP was negatively correlated with MoCA; while total cholesterol, HDL-C and LDL-C were positively correlated with the MoCA, respectively.

Conclusion: Our findings suggest that lower SOD along with cholesterol, HDL-C and LDL-C, and higher hsCRP levels might be important markers to assess the PD severity. A better understanding of SOD and hsCRP may yield insights into the pathogenesis of PD.