Mortality and quality of death certification in a cohort of patients with Parkinson's disease and matched controls in North Wales, UK at 18 years: a community-based cohort study

An Overview of Epigenetic Changes in the Parkinson's Disease Brain

Parkinson's disease is a progressive neurodegenerative disorder, predominantly of the motor system. Although some genetic components and cellular mechanisms of Parkinson's have been identified, much is still unknown. In recent years, emerging evidence has indicated that non-DNA-sequence variation (in particular epigenetic mechanisms) is likely to play a crucial role in the development and progression of the disease. Here, we present an up-to-date overview of epigenetic processes including DNA methylation, DNA hydroxymethylation, histone modifications and non-coding RNAs implicated in the brain of those with Parkinson's disease. We will also discuss the limitations of current epigenetic research in Parkinson's disease, the advantages of simultaneously studying genetics and epigenetics, and putative novel epigenetic therapies.

Associations of Long-term Sleep Duration Trajectories with Overall and Cause-Specific Mortality Among Middle-to-older Aged Black and White Adults

Background

Both short and long sleep durations are adversely associated with numerous chronic conditions, including cardiovascular disease (CVD), diabetes, hypertension, and mortality. The American Academy of Sleep Medicine recommends adults in the United States sleep at least 7 hours and less than 9 hours per night to maintain optimal health. It remains unclear how sleep duration trajectories over time are associated with mortality.

Methods

This observational cohort study includes 46,928 Black and White adults (mean age: 53 ± 9 years) who enrolled in the Southern Community Cohort Study between 2002-2009 and completed a follow-up survey in 2008-2013. Participants were categorized into nine sleep duration trajectory categories based on the reported average sleep duration between study enrollment and at follow-up. Participant vital status and date and cause of death were ascertained via linkage to the National Death Index through 2022. Cox regression analysis was performed to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between sleep duration trajectory and all-cause and cause-specific mortality (CVD, cancer, and neurodegenerative disease) after adjustment for sociodemographic characteristics, health behaviors, and clinical factors.

Results

During a median 12.6 years of follow-up, we documented 13,579 deaths, including 4,135 from CVD, 3,067 from cancer, and 544 from neurodegenerative diseases. Compared to the optimal sleep duration trajectory (maintaining 7-9 hours), all sub-optimal trajectories were associated with significant 6 to 33% greater risk of all-cause mortality in fully adjusted models. Compared to the optimal sleep trajectory, three of the sub-optimal trajectories were associated with increased CVD mortality, with HRs ranging from 1.20 to 1.34. The short-long trajectory was associated with the greatest risk of all-cause mortality (HR:1.33; 95%CI: 1.21, 1.46) and the long-short trajectory was associated with the greatest CVD mortality risk (HR:1.34; 95%CI: 1.10, 1.65). The healthy-long trajectory was associated with the greatest risk of cancer mortality (HR: 1.19; 95%CI:1.00, 1.41). None of the sub-optimal trajectories was associated with neurodegenerative disease mortality.

Conclusions

Suboptimal sleep duration trajectories were associated with increased risk of all-cause mortality as well as CVD mortality. Findings highlight the importance of maintaining healthy sleep duration throughout midlife to reduce mortality risk.

Misclassification of causes of death among a small all-autopsied group of former nuclear workers: Death certificates vs. autopsy reports

The U.S. Transuranium and Uranium Registries performs autopsies on each of its deceased Registrants as a part of its mission to follow up occupationally-exposed individuals. This provides a unique opportunity to explore death certificate misclassification errors, and the factors that influence them, among this small population of former nuclear workers. Underlying causes of death from death certificates and autopsy reports were coded using the 10th revision of the International Classification of Diseases (ICD-10). These codes were then used to quantify misclassification rates among 268 individuals for whom both full autopsy reports and death certificates with legible underlying causes of death were available. When underlying causes of death were compared between death certificates and autopsy reports, death certificates correctly identified the underlying cause of death's ICD-10 disease chapter in 74.6% of cases. The remaining 25.4% of misclassified cases resulted in over-classification rates that ranged from 1.2% for external causes of mortality to 12.2% for circulatory disease, and under-classification rates that ranged from 7.7% for external causes of mortality to 47.4% for respiratory disease. Neoplasms had generally lower misclassification rates with 4.3% over-classification and 13.3% under-classification. A logistic regression revealed that the odds of a match were 2.8 times higher when clinical history was mentioned on the autopsy report than when it was not. Similarly, the odds of a match were 3.4 times higher when death certificates were completed using autopsy findings than when autopsy findings were not used. This analysis excluded cases where it could not be determined if autopsy findings were used to complete death certificates. The findings of this study are useful to investigate the impact of death certificate misclassification errors on radiation risk estimates and, therefore, improve the reliability of epidemiological studies.

Electrocardiographic approach strategies in patients with Parkinson disease treated with deep brain stimulation

Deep brain stimulation (DBS) is an interdisciplinary and reversible therapy that uses high-frequency electrical stimulation to correct aberrant neural pathways in motor and cognitive neurological disorders. However, the high frequency of the waves used in DBS can interfere with electrical recording devices (e.g., electrocardiogram, electroencephalogram, cardiac monitor), creating artifacts that hinder their interpretation. The compatibility of DBS with these devices varies and depends on factors such as the underlying disease and the configuration of the neurostimulator. In emergencies where obtaining an electrocardiogram is crucial, the need for more consensus on reducing electrical artifacts in patients with DBS becomes a significant challenge. Various strategies have been proposed to attenuate the artifact generated by DBS, such as changing the DBS configuration from monopolar to bipolar, temporarily deactivating DBS during electrocardiographic recording, applying frequency filters both lower and higher than those used by DBS, and using non-standard leads. However, the inexperience of medical personnel, variability in DBS models, or the lack of a controller at the time of approach limit the application of these strategies. Current evidence on their reproducibility and efficacy is limited. Due to the growing elderly population and the rising utilization of DBS, it is imperative to create electrocardiographic methods that are easily accessible and reproducible for general physicians and emergency services.

Cognitive Reserve in Parkinson's Disease without Dementia: β-Amyloid and Metabolic Assessment

BACKGROUND

Cognitive reserve (CR) is the mismatch between preserved cognition and neuropathological damage. Amyloidopathy in Parkinson's disease (PD) could be associated with faster progression to dementia, but the putative protective effect of CR is unknown.

OBJECTIVES

To evaluate the effect of CR on β-amyloid burden and brain metabolism in non-demented PD subjects.

METHODS

Participants with PD (n = 53) underwent a clinical evaluation, [18 F]-fluorodeoxyglucose and [18 F]-flutemetamol positron emission tomography magnetic resonances, and were classified according to CR. The metabolic pattern of 16 controls was compared to PD subjects.

RESULTS

The PD subjects showed hypometabolism mainly in the bilateral posterior cortex. Superior-CR subjects (n = 22) exhibited better cognitive performance, increased amyloid burden, and higher metabolism in several right hemisphere areas compared to low-medium-CR subjects (n = 31).

CONCLUSIONS

Higher CR in non-demented PD is associated with better cognitive performance, which might reduce vulnerability to the effect of β-amyloid. Whether superior CR leads to protection against metabolic deterioration, and predominantly right hemisphere involvement, deserves further exploration.

Development of a Core Outcome Set for Dysphagia Interventions in Parkinson's disease (COS-DIP): study protocol

INTRODUCTION

Current clinical trials on swallowing disorders (dysphagia) in Parkinson's disease (PD) apply a high variety of outcomes and different outcome measures making comparative effectiveness research challenging. Furthermore, views of patients and dysphagia clinicians when selecting trial outcomes have not been considered in the past, thus study results may have little importance to them. This study aims to develop an agreed standardised Core Outcome Set for Dysphagia Interventions in Parkinson's disease (COS-DIP), systematically measured and reported as a minimum for all clinical trials. It will also comprise guidance on outcome definitions, outcome measures and time points of measurement.

METHODS AND ANALYSIS

The COS-DIP development will comprise five stages following established methodology: (1) a recent scoping review on all applied outcomes, their definitions, methods and time points of measurement in clinical trials in dysphagia in PD, (2) online surveys and focus groups with clinicians, patients, caregivers and family members to identify outcomes that are important to them, (3) an identified list of outcomes based on results of stage 1 and 2, (4) three round online Delphi survey with up to 200 key stakeholders to determine core outcomes and (5) two online consensus meetings with up to 40 representative key stakeholders to agree on all outcomes, definitions, methods and time points of measurement in the final COS-DIP.

ETHICS AND DISSEMINATION

Full ethical approval was obtained from the Research Ethics Committee, School of Linguistic, Speech and Communication Sciences, Trinity College Dublin, on 15 May 2023 (HT27). Dissemination of the COS-DIP will be enhanced through presentations at (inter-) national conferences and through peer-reviewed, open access publications of related manuscripts. Lay and professional information sheets and infographics will be circulated through relevant patient and professional organisations and networks.

TRIAL REGISTRATION NUMBER

The COS-DIP study was registered prospectively with the Core Outcome Measures in Effectiveness Trials (COMET) database on 24 September 2021 (www.comet-initiative.org/Studies/Details/1942).

Case-Fatality Rate in Parkinson's Disease: A Nationwide Registry Study

BACKGROUND

Patients with Parkinson's disease (PD) may have an increased risk of mortality, but robust estimates are lacking.

OBJECTIVE

To compare mortality rates nationally between patients with PD and controls.

METHODS

The case-fatality rates of Finnish PD patients diagnosed in 2004-2018 (n = 23,688; 57% male, mean age at diagnosis = 71 years) and randomly selected sex- and age-matched control subjects (n = 94,752) were compared using data from national registries. The median follow-up duration was 5.8 years (max 17 years).

RESULTS

The case-fatality rate in patients with PD was higher than that in matched controls (HR 2.29; 95% CI 2.24-2.33; P < 0.0001). Excess fatality among PD patients was already present at 1 year from diagnosis and then plateaued at 29% at 12 years after diagnosis. The long-term relative hazard of death in PD patients vs. matched controls did not differ based on sex. Patients with early-onset PD (age at diagnosis <50 years old) had the highest relative hazard of death (HR 3.36) compared to matched control subjects, and the relative hazard decreased with higher age at diagnosis. The seven-year excess risk of death decreased during the study period, especially in men. In patients with PD, male sex, increasing age, and increasing comorbidity burden were associated with an increased risk of death.

CONCLUSIONS

An increased risk of death among PD patients was evident from early on. The increase in risk was greatest among young-onset patients. The excess risk in early PD declined during the study period, particularly in men. The reasons for this are unknown.

Underserved groups in dysphagia intervention trials in Parkinson's disease: A scoping review

BACKGROUND

Underserved groups in Parkinson's disease (PD) intervention studies are well recognised. However, it remains unclear whether these exclusions apply to oropharyngeal dysphagia (OD) intervention studies in PD. The aim of this scoping review was to identify characteristics of included participants and underserved groups in intervention studies in OD in PD.

METHODS

Six electronic databases and one trial registry were searched without language restrictions. Screening of studies and data extraction were independently conducted by four reviewers.

RESULTS

Of the 26 studies included, none fully reported the participants' ethnicity. Where data was available, 70% of participants were male with a mean age of 68 years, mean PD duration of 7.26 years, median Hoehn and Yahr stage of 2.5, mild OD and mostly recruited from movement disorders clinics. Underserved groups were younger people (< 50 years), older people (≥ 80 years), women, non-white people, people with severe OD and PD, longer PD duration, other neurological conditions, cognitive impairment/dementia, and depression.

CONCLUSIONS

Careful consideration of all characteristics of individuals with OD in PD is essential for improving the external validity of studies. This will enhance the generalisability of research findings to the broader PD population, ultimately strengthening the evidence base for OD interventions in PD.

Terminal Care in Parkinson's Disease: Real-Life Use of Continuous Subcutaneous Apomorphine Infusion to Improve Patient Comfort

BACKGROUND

There are currently no recommendations on the therapeutic management of Parkinson's disease (PD) patients at the end of life.

OBJECTIVE

To describe a cohort of patients with PD who benefited from continuous subcutaneous apomorphine infusion (CSAI) initiation at the end of their life as comfort care.

METHODS

This real-life cohort includes 14 PD patients, who benefited from 24-h, low-dose CSAI (0.5-3 mg/h) in the context of terminal care. Patient's comfort (pain, rigidity, and/or ability to communicate) and occurrence of CSAI-related side-effects (nausea/vomiting, cutaneous and behavioral manifestations) were evaluated based on medical records.

RESULTS

All patients (age 62-94 years, disease duration 2-32 years) presented with late-stage PD and a compromised oral route. Treatment lasted from a few hours to 39 days. CSAI led to substantial functional improvement, with a good safety profile. Overall clinical comfort was deemed improved by the medical team, the patient, and/or caregivers.

CONCLUSIONS

CSAI might be a promising approach in PD terminal care, as it reduces motor symptoms and overall discomfort, with an apparent good safety profile. Use of the apomorphine pen, sublingual film or a classic syringe pump might be considered when apomorphine pumps are not available. Larger observational cohorts and randomized controlled trials are needed to establish the efficacy and tolerability of apomorphine in the context of terminal care and more broadly, in an advance care planning perspective.

Association between Parkinson's disease and the risk of adverse cardiovascular events: a systematic review and meta-analysis

Background

This review aims to examine the association of Parkinson's disease (PD) with the increased risk of cardiovascular events.

Methods

PubMed, Embase, CENTRAL, and Scopus databases were electronically searched for papers published up to 5 May 2023. Studies reporting the association between PD and the subsequent risks of stroke, myocardial infarction (MI), and cardiovascular mortality were included.

Results

Sixteen studies were included in this review. The clinical data of 101,712 PD patients were compared with that of the control group of 204,901 patients without PD in the included studies. Meta-analysis showed that PD patients had an increased risk of stroke compared with patients without PD (odds ratio (OR): 1.49; 95% confidence interval (CI): 1.30, 1.72; I2 = 76%). The pooled analysis demonstrated no significant increase in the risk of MI (OR: 1.16; 95% CI: 0.85, 1.59; I2 = 82%) and cardiovascular mortality (OR: 1.20; 95% CI: 0.93, 1.54; I2 = 65%) in PD patients. However, data from cohort studies indicated a possibility of higher risk of MI (OR: 1.36; 95% CI: 1.01, 1.84; I2 = 80%) and cardiovascular mortality (OR: 1.22; 95% CI: 1.00, 1.60; I2 = 62%) in patients with PD.

Conclusion

Patients with PD may have an increased risk of stroke as compared with the age- and gender-matched general population. While our results show that PD does not increase the overall risk of MI and cardiovascular mortality, analysis of cohort studies alone demonstrated that these risks may be higher in patients with PD. The current evidence is of very low quality. Further prospective cohort studies from different countries that would account for important cardiovascular risk factors are needed to improve the current evidence.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, PROSPERO (CRD42023421924).

Mortality and causes of death in patients with Parkinson's disease: a nationwide population-based cohort study

Objective

Parkinson's disease (PD) is a neurodegenerative disease involving multiple systems that can affect mortality. This study aimed to compare all-cause and cause-specific mortality between people with PD and without PD.

Methods

This population-based prospective cohort study is based on Korean National Health Insurance Service data. The primary outcome was the hazard ratio (HR) of all-cause and cause-specific mortality for PD from 2010 to 2019. Cox proportional hazards regression was applied to calculate HRs under crude and three adjusted models with epidemiologic variables.

Results

A total of 8,220 PD patients and 41,100 age- and sex-matched controls without PD were registered. Ten-year mortality was 47.9% in PD patients and 20.3% in non-PD controls. The mortality rate was higher among older and male participants. The leading cause of death in PD was nervous system diseases (38.73%), and 97.1% of those were extrapyramidal and movement disorders, followed by circulatory diseases (15.33%), respiratory diseases (12.56%), and neoplasms (9.7%). PD contributed to an increased risk of all-cause death with an HR of 2.96 (95% CI = 2.84-3.08). HRs of death for PD were 3.07 (95% CI = 2.74-3.45) from respiratory diseases, 1.93 (95% CI = 1.75-2.13) from circulatory diseases, 2.35 (95% CI = 2.00-2.77) from external causes, and 2.69 (95% CI = 2.10-3.43) from infectious diseases.

Conclusion

These results showed that PD was related to a higher risk of mortality in all ages and sexes. The leading causes of death in PD were nervous, circulatory, respiratory, infectious diseases, and external causes.

Role of cardiac β1-adrenergic and A1-adenosine receptors in severe arrhythmias related to Parkinson's disease

AIMS

Although reduced life expectancy in Parkinson's Disease (PD) patients has been related to severe cardiac arrhythmias due to autonomic dysfunctions, its molecular mechanisms remain unclear. To investigate the role of cardiac β1-Adrenergic (β1AR) and A1-Adenosine (A1R) receptors in these dysfunctions, the pharmacological effects of stimulation of cardiac β1AR (isoproterenol, ISO), in the absence and presence of cardiac β1AR (atenolol, AT) or A1R (1,3-dipropyl-8-cyclopentyl xanthine, DPCPX) blockade, on the arrhythmias induced by Ischemia/Reperfusion (CIR) in an animal PD model were studied.

METHODS

PD was produced by dopaminergic lesions (confirmed by immunohistochemistry analysis) caused by the injection of 6-hydroxydopamine (6-OHDA, 6 μg) in rat striatum. CIR was produced by a surgical interruption for 10 min followed by reestablishment of blood circulation in the descendent left coronary artery. On the incidence of CIR-Induced Ventricular Arrhythmias (VA), Atrioventricular Block (AVB), and Lethality (LET), evaluated by Electrocardiogram (ECG) analysis, the effects of intravenous treatment with ISO, AT and DPCPX (before CIR) were studied.

RESULTS

VA, AVB and LET incidences were significantly higher in 6-OHDA (83%, 92%, 100%, respectively) than in control rats (58%, 67% and 67%, respectively). ISO treatment significantly reduced these incidences in 6-OHDA (33%, 33% and 42%, respectively) and control rats (25%, 25%, 33%, respectively), indicating that stimulation of cardiac β1AR induced cardioprotection. This response was prevented by pretreatment with AT and DPCPX, confirming the involvement of cardiac β1AR and A1R.

CONCLUSION

Pharmacological modulation of cardiac β1AR and A1R could be a potential therapeutic strategy to reduce severe arrhythmias and increase life expectancy in PD patients.

Mortality rates and proximal causes of death in patients with Lewy body dementia versus Alzheimer's disease: A longitudinal study using secondary care mental health records

BACKGROUND

Previous studies have shown reduced survival in Lewy body dementia (LBD) compared to Alzheimer's disease (AD), but the reasons for this are not known. We identified cause of death categories accounting for the reduced survival in LBD.

METHODS

We linked cohorts of patients with dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD) and AD, with proximal cause of death data. We examined mortality by dementia group and hazard ratios for each death category by dementia group in males and females separately. In a specific focus on the dementia group with the highest mortality rate versus reference, we examined cumulative incidence to identify the main causes of death accounting for the excess deaths.

RESULTS

Hazard ratios for death were higher in PDD and DLB compared to AD, for both males and females. PDD males had the highest hazard ratio for death across the dementia comparison groups (HR 2.7, 95% CI 2.2-3.3). Compared with AD, hazard ratios for "nervous system" causes of death were significantly elevated in all LBD groups. Additional significant cause-of-death categories included aspiration pneumonia, genitourinary causes, other respiratory causes, circulatory and a "symptoms and signs" category in PDD males; other respiratory causes in DLB males; mental disorders in PDD females; and aspiration pneumonia, genitourinary and other respiratory causes in DLB females.

CONCLUSION

Further research and cohort development is required to investigate differences by age group, to extend cohort follow-up to the whole population and to investigate the risk-balance of interventions which may differ by dementia group.

Association between smoking and all-cause mortality in Parkinson's disease

We aimed to investigate the association between smoking status and all-cause mortality of Parkinson's disease (PD). Among the whole nationwide population data from Korea National Health Insurance Service, newly diagnosed PD was selected, and all-cause mortality was evaluated. The systematic review was performed through a literature search on the PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases. Among 26,080 individuals with PD, there was no significant association between smoking status and all-cause mortality in a nationwide cohort study (ex-smoker, HR 0.1.03, 95% CI 0.97-1.10; current smoker, HR 1.06, 95% CI 0.96-1.16). The systematic review, including six prospective cohort studies, also found a nonsignificant association. PD smokers tended to have fewer deaths from neurologic causes but were significantly more likely to die from smoking-related cancers such as lung cancer. We presented a nonsignificant association between smoking and mortality of PD, and cigarette smoking is not recommended in individuals with PD.

Swallowing outcomes in dysphagia interventions in Parkinson's disease: a scoping review

OBJECTIVES

To identify all outcomes, their definitions, outcome measurement instruments (OMIs), timepoints and frequency of measurement applied in clinical trials in oropharyngeal dysphagia (OD) interventions in Parkinson's disease (PD). This scoping review is the first stage of a larger project establishing a core outcome set for dysphagia interventions in Parkinson's disease (COS-DIP).

DESIGN

Scoping review.

METHODS

Six electronic databases and one trial registry were searched without language restrictions until March 2022. Bibliography lists of included studies were also reviewed. Study screening and data extraction were conducted independently by two reviewers using Covidence. The scoping review protocol is registered and published (http://hdl.handle.net/2262/97652).

RESULTS

19 studies with 134 outcomes were included. Trial outcomes were mapped to a recommended taxonomy for COSs and merged. 39 outcomes were identified. The most frequently measured were general swallowing-related outcomes, global quality-of-life outcomes and swallowing-related perceived health status outcomes. The applied outcomes, their definitions, OMIs, timepoints and frequency of measurement showed a high variability across all studies.

CONCLUSIONS

The high variability of outcomes emphasises the need for an agreed standardised COS. This will inform clinical trial design in OD in PD, increase the quality of OD trials in PD and facilitate synthesising and comparing study results to reach conclusion on the safety and effectiveness of OD interventions in PD. It will not prevent or restrict researchers from examining other outcomes.

TRIAL REGISTRATION NUMBER

The COS-DIP study, including the scoping review, was registered prospectively with the Core Outcome Measures in Effectiveness Trials Database on 24 September 2021 (www.comet-initiative.org, registration number: 1942).

Causes, factors, and complications associated with hospital admissions among patients with Parkinson's disease

Introduction

Patients with Parkinson's disease (PD) are at a higher risk of hospital admissions compared to the general population. We studied the causes and factors associated with admissions among patients with PD over 6 years.

Methods

We included all PD admissions between 1 January 2016 and 31 December 2021. Other causes of parkinsonism were excluded. Causes of admissions were divided into PD-related (direct or indirect) or non-PD-related. The type of admission was categorized into emergency or elective.

Results

We identified 605 hospital admissions (259 patients with PD); 345 (57.0%) were PD-related and 260 (43%) were non-PD-related. Emergency PD admissions contributed to 50.4% of all admissions, most commonly from respiratory infection (23%). PD admissions in comparison to non-PD admissions were associated with worse disease severity (HY ≥ 3; p < 0.001), longer disease duration [8.71 (SD 6.23) vs. 6.60 (SD 5.39) years; p < 0.001], and longer hospital stay [7.70 (SD 5.89) vs. 6.42 (SD 7.63) days; p = 0.020]. Non-PD admissions were associated with more comorbidities (97.3%; p = 0.013). There were 124 (20.5%) complications and 31 deaths (5.1%). A total of 29 deaths were due to respiratory infection and 3 deaths were due to COVID-19 pneumonia. Emergency admission (PD- and non-PD-related; p = 0.001) and respiratory-related causes (p < 0.001) were predictors of unfavorable hospital admission outcomes (death and complications).

Conclusion

Respiratory infection was the leading cause of hospital admission and a significant independent predictor of unfavorable hospital admission outcomes (death and complications). PD-related admissions were associated with disease severity and led to more complications and longer hospital stays. Non-PD-related admissions were associated with comorbidities.

The dilemma between milestones of progression versus clinical scales in Parkinson's disease

There are significant challenges in accurately documenting the progression of Parkinson's disease (PD). The disease course is highly heterogeneous, there are no validated biomarkers, and we are reliant on repeated clinical measures to assess disease state over time. Yet, the ability to chart disease progression accurately is vital in both observational and interventional study designs, where reliable measures are critical to determine whether an outcome has been met. In this chapter, we first discuss the natural history of PD, including the spectrum of clinical presentation and expected developments through the course of the disease. We then explore in detail the current strategies for measuring disease progression, which can be broadly divided into: (i) the use of quantitative clinical scales; and (ii) determination of the onset time of key milestones. We discuss the strengths and limitations of these approaches for use in clinical trials, with a particular focus on disease modification trials. The selection of outcome measures for a particular study will depend on multiple factors, but trial duration is an important determinant. Milestones are reached over a course of years rather than months, and hence clinical scales with sensitivity to change are needed for short-term studies. However, milestones represent important markers of disease stage which are not confounded by symptomatic therapies and are of critical relevance to the patient. Prolonged but low intensity follow-up beyond a limited period of treatment with a putative disease-modifying agent may allow milestones to be incorporated into evaluation of efficacy in a practical and cost-effective way.

Long-term air pollution exposure and Parkinson's disease mortality in a large pooled European cohort: An ELAPSE study

BACKGROUND

The link between exposure to ambient air pollution and mortality from cardiorespiratory diseases is well established, while evidence on neurodegenerative disorders including Parkinson's Disease (PD) remains limited.

OBJECTIVE

We examined the association between long-term exposure to ambient air pollution and PD mortality in seven European cohorts.

METHODS

Within the project 'Effects of Low-Level Air Pollution: A Study in Europe' (ELAPSE), we pooled data from seven cohorts among six European countries. Annual mean residential concentrations of fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), black carbon (BC), and ozone (O₃), as well as 8 PM_2.5 components (copper, iron, potassium, nickel, sulphur, silicon, vanadium, zinc), for 2010 were estimated using Europe-wide hybrid land use regression models. PD mortality was defined as underlying cause of death being either PD, secondary Parkinsonism, or dementia in PD. We applied Cox proportional hazard models to investigate the associations between air pollution and PD mortality, adjusting for potential confounders.

RESULTS

Of 271,720 cohort participants, 381 died from PD during 19.7 years of follow-up. In single-pollutant analyses, we observed positive associations between PD mortality and PM_2.5 (hazard ratio per 5 µg/m³: 1.25; 95% confidence interval: 1.01-1.55), NO₂ (1.13; 0.95-1.34 per 10 µg/m³), and BC (1.12; 0.94-1.34 per 0.5 × 10^-5m^-1), and a negative association with O₃ (0.74; 0.58-0.94 per 10 µg/m³). Associations of PM_2.5, NO₂, and BC with PD mortality were linear without apparent lower thresholds. In two-pollutant models, associations with PM_2.5 remained robust when adjusted for NO₂ (1.24; 0.95-1.62) or BC (1.28; 0.96-1.71), whereas associations with NO₂ or BC attenuated to null. O₃ associations remained negative, but no longer statistically significant in models with PM_2.5. We detected suggestive positive associations with the potassium component of PM_2.5.

CONCLUSION

Long-term exposure to PM_2.5, at levels well below current EU air pollution limit values, may contribute to PD mortality.

A systematic review on the risk of neurodegenerative diseases and neurocognitive disorders in professional and varsity athletes

Objective

The aim of this systematic review (SR) was to gather all available epidemiological evidence on former participation in any type of sport, at a professional and varsity level, as a potential risk factor for neurodegenerative diseases (NDs) and neurocognitive disorders (NCDs).

Design

Systematic searches were performed on PubMed, the Cochrane databases, and the ISI Web of Knowledge databases. Included studies were assessed using the NOS checklist.

Eligibility criteria for selecting studies

All epidemiological studies reporting data on the possible association between a clinical diagnosis of amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND), dementia or mild cognitive impairment (MCI), Parkinson’s disease (PD), chronic traumatic encephalopathy (CTE) at any stage and with any clinical pattern and the former participation in any types of sport at a varsity and professional level were included.

Results

Data from the 17 included studies showed a higher frequency of NDs and NCDs in former soccer and American football players. Updating the previous SR confirmed a higher frequency of ALS/MND in former soccer players. Data reported a significantly higher risk of dementia/AD in former soccer players, and of MCI in former American football players. Results also showed a significantly higher risk of PD in former soccer and American football players, and a significantly higher risk of CTE in former boxers and American football players.

Summary/conclusions

This SR confirmed a higher risk of NDs and NCDs in former professional/varsity athletes. However, the pathological mechanisms underlying this association remain unclear, and further high-quality studies should be performed to clarify whether the association could be sport specific.

Long-term exposure to residential greenness and neurodegenerative disease mortality among older adults: a 13-year follow-up cohort study

BACKGROUND

Living in greener areas is associated with slower cognitive decline and reduced dementia risk among older adults, but the evidence with neurodegenerative disease mortality is scarce. We studied the association between residential surrounding greenness and neurodegenerative disease mortality in older adults.

METHODS

We used data from the 2001 Belgian census linked to mortality register data during 2001-2014. We included individuals aged 60 years or older and residing in the five largest Belgian urban areas at baseline (2001). Exposure to residential surrounding greenness was assessed using the 2006 Normalized Difference Vegetation Index (NDVI) within 500-m from residence. We considered all neurodegenerative diseases and four specific outcomes: Alzheimer's disease, vascular dementia, unspecified dementia, and Parkinson's disease. We fitted Cox proportional hazard models to obtain hazard ratios (HR) and 95% confidence intervals (CI) of the associations between one interquartile range (IQR) increment in surrounding greenness and neurodegenerative disease mortality outcomes, adjusted for census-based covariates. Furthermore, we evaluated the potential role of 2010 air pollution (PM_2.5 and NO₂) concentrations, and we explored effect modification by sociodemographic characteristics.

RESULTS

From 1,134,502 individuals included at baseline, 6.1% died from neurodegenerative diseases during follow-up. After full adjustment, one IQR (0.22) increment of surrounding greenness was associated with a 4-5% reduction in premature mortality from all neurodegenerative diseases, Alzheimer's disease, vascular and unspecified dementia [e.g., for Alzheimer's disease mortality: HR 0.95 (95%CI: 0.93, 0.98)]. No association was found with Parkinson's disease mortality. Main associations remained for all neurodegenerative disease mortality when accounting for air pollution, but not for the majority of specific mortality outcomes. Associations were strongest in the lower educated and residents from most deprived neighbourhoods.

CONCLUSIONS

Living near greener spaces may reduce the risk of neurodegenerative disease mortality among older adults, potentially independent from air pollution. Socioeconomically disadvantaged groups may experience the greatest beneficial effect.

Parkinson's disease related mortality: Long-term trends and impact of COVID-19 pandemic waves

Introduction

Parkinson's disease (PD) mortality burden is increasing worldwide, but accurate estimates on the magnitude of the impact of the COVID-19 pandemic are missing. Mortality rates vary largely when considering PD as underlying cause of death (UCOD), or as one among multiple causes reported in death certificates (MCOD). The aim of this study is to assess COVID-19 impact on PD-related mortality trends using the UCOD and MCOD approach.

Methods

Mortality records between 01/2008-12/2020 of residents aged ≥45 years in Veneto Region (Northeastern Italy) with any mention of PD were collected. Age-standardized sex-specific mortality rates were estimated for PD-related deaths as UCOD and MCOD to assess time trends. The average annual percentage change in age-standardized rates (AAPC) was estimated by linear regression models. Monthly mortality in 2020, the first year of the pandemic, was plotted against the 2018–2019 average.

Results

Overall, 13,746 PD-related deaths (2.3% of all deaths) were identified, 52% males, median age 84 years. Proportional mortality increased from 1.9% (2008) to 2.8% (2020). AAPC through 2008–2019 was +5.2% for males and +5.3% for females in analyses of the UCOD, and +1.4% in both genders based on MCOD. Excess in PD-related mortality during 2020 corresponded to 19% for UCOD and 28% for MCOD, with the latter showing two peaks corresponding to the first (28%) and second (59%) pandemic waves.

Conclusion

Age-standardized PD-related mortality rates have steeply increased during COVID-19 pandemic, amplifying a pre-existing long-term trend. Hence, surveillance of mortality associated to PD is warranted in the forthcoming pandemic and post-pandemic years.

Association of Essential Tremor With Dementia and Affective Disorders: A Meta-Analysis

Background

The dementia and affective disorders are common non-motor features in patients with essential tremor (ET). However, the relationship of ET with cognitive impairments and affective disorders remains controversial. This meta-analysis aimed to analyze the association of ET with dementia and affective disorders.

Methods

Original studies published from January 1999 to October 2019 were systematically searched from the database of Medline (OvidSP), EMBASE (OvidSP), and the Cochrane Central Register of Controlled Trials. Pooled standard mean difference (SMD, random effect model), odds ratios (ORs), relative risk (RR), and 95% CI were calculated.

Results

Compared with the Non-ET group, patients with ET had significantly lower Mini-Mental State Examination (MMSE) score (SMD, −1.16; 95% CI, −1.75 to −0.58; p = 0.0001) and had significantly higher depressive and anxiety symptoms scale score (SMD, 0.55; 95% CI, 0.22–0.87; p = 0.0009). The OR for dementia and affective disorders in individuals with ET compared with individuals without ET was 2.49 (95% CI, 2.17–2.85, p &lt; 0.00001). While there was no significant difference in Montreal Cognitive Assessment (MoCA) score between ET and Non-ET groups (SMD, −0.52; 95% CI, −0.16 to 0.13; p = 0.23), there was a significant difference in the risk of mortality between ET and Non-ET groups (RR = 4.69, 95% CI, 2.18–10.07).

Conclusion

The non-motor symptoms should not be neglected among patients with ET. However, the causal relationship between ET and dementia, depression, and anxiety is unclear.

Genetic predisposition to Parkinson's disease and risk of cardio and cerebrovascular disease: a Mendelian randomization study

BACKGROUND

Observational studies suggest that Parkinson's disease (PD) is related with the risk of cardio and cerebrovascular disease. However, the causality is not yet fully established. Therefore, we employed Mendelian randomization to assess whether PD is related to risk of ischemic stroke (IS), IS subtypes, coronary artery disease (CAD) and myocardial infarction (MI).

METHODS

Eighty-eight and eleven single nucleotide polymorphisms associated with PD at the genome-wide significance level, were used as instrumental variables for PD in European and East Asian population respectively. Using a 2-sample MR, we examined associations with IS, IS related subtypes, CAD and MI in European population. We also assessed the causal association of PD with IS and CAD in East Asian population. The primary MR analyses were performed by using the random-effects inverse variance weighted approach.

RESULTS

In European population, genetic predisposition to PD was related to higher risk of IS (odds ratio [OR], 1.03 per doubling in odds of PD; 95% confidence interval [CI], 1.01-1.05; P = 0.002) and cardioembolic stroke (OR, 1.08 per doubling in odds of PD; 95% CI, 1.04-1.12; P = 1.29 × 10^-4), but not large artery stroke, small vessel stroke, CAD and MI. In East Asian population, we found no evidence of causal effect of PD on the risk of IS and CAD.

CONCLUSIONS

This study found that genetic predisposition to PD is related to higher risk of IS and cardioembolic stroke in European population.

Integration of palliative care in Parkinson's disease management

BACKGROUND

Parkinson's disease is a progressive neurodegenerative disorder that negatively impacts the lives of affected people. The therapeutic benefits of treatment only decrease going forward from the time of diagnosis. Motor and non-motor symptoms alike create a heavy burden for patients and those involved in their care. Palliative care is utilized for patients with serious illnesses and when integrated into patients with Parkinson's disease, improves quality of life by addressing symptoms of discomfort, which ultimately reduces symptom burden to patients and alleviates caregiver stress.

OBJECTIVE

This review aims to assess the efficacy of palliative care in the management of Parkinson's disease by exploring the benefits of palliative care integration throughout multiple relevant themes to demonstrate the optimal care delivery.

METHODS

Comprehensive searches on the role of palliative care in Parkinson's disease patients within MEDLINE, PUBMED, CINAHL, CENTRAL, PsycINFO, Embase, and BioMed Central, considering publications between March 2010 - February 2020 were performed. A grey literature search was also performed for additional information.

RESULTS

Analysis of various existing literature has demonstrated promise in timely palliative care integration for patients with Parkinson's disease, which has shown improvement in the quality of life of Parkinson's disease patients. It also strives to alleviate caregivers' stress and improve their quality of life, although insufficient research exists to support this. Palliative care in Parkinson's disease is a growing area of interest, evidently demonstrating the potential to expand among the current approaches.

CONCLUSION

Understanding the connections between the themes surrounding palliative care is crucial for successful integration in Parkinson's disease management. It is determined that integration of palliative care in patients with Parkinson's disease help to not only improve patients' experiences but also their caregiver's experiences throughout the disease trajectory. Further research should be conducted to address how palliative care will focus on alleviating caregiver burden and establish specific prognostication tools for Parkinson's disease patients.

Mortality of People with Parkinson's Disease in a Large UK-Based Cohort Study: Time Trends and Relationship to Disease Duration

Background

Parkinson’s disease (PD) is associated with increased mortality, but little is known about changes over time, and relationship to disease progression.

Objectives

To explore how PD mortality rates have changed over time and their relationship to disease duration and demographics using a large population-based cohort in the UK.

Methods

We included individuals aged 50+ years with a first recording of PD diagnosis and at least two prescriptions of any antiparkinsonian drug actively registered within a general practice from 2006 to 2016 and up to six frequency-matched controls from The Health Improvement Network (THIN) database. We estimated adjusted mortality rates using multivariable Poisson regression.

Results

A total of 10,104 people with a diagnosis of PD and 55,664 people without PD were included. Overall, PD was associated with slightly increased mortality compared to non-PD controls (adjusted mortality rate ratio: 1.14; 95% CI: 1.03 to 1.19). Adjusted mortality rates per 1000 person-years at risk for people with PD approximately doubled in the 5 years following diagnosis from 43 (95% CI: 38 to 48) to 75 (95% CI: 64 to 85). Following adjustments for age, gender, and time since diagnosis, mortality rates between 2007 and 2016 declined more slowly for people with PD (2% per year; 95% CI: 0%–4%) compared to people without PD (5% per year; 95% CI: 3%–6%).

Conclusions

Whilst mortality in PD is only slightly increased overall, it gradually increases with advancing disease. There has been a decline in mortality in PD over time, but this decrease was less pronounced than that in the general population.

Mortality from Parkinson's disease and other causes among a workforce manufacturing paraquat: an updated retrospective cohort study

BACKGROUND

Epidemiological studies of the association between Parkinson's disease (PD) and paraquat (PQ) exposure have given inconsistent findings. The aim of the study was to update information on the risk of PD and mortality from major causes of death among a UK workforce who manufactured PQ by extending the follow-up by seven and a half years.

METHODS

This retrospective cohort study included all employees who had ever worked on any of the four plants at Widnes, UK where PQ was manufactured between 1961 and 1995. The 926 male and 42 female workers were followed through 31 December 2017. Mortalities for males were compared with national and local rates, including rates for PD as a mentioned cause of death.

RESULTS

A total of 394 male and 21 female workers had died by end of follow-up. Four death certificates of male workers mentioned PD, including two deaths that were due to PD. At least 6 death certificates of male employees would have been expected to have mentioned PD (SMR = 0.67; 95% CI 0.18-1.72). Reduced mortalities compared with local rates were found for major causes of death.

CONCLUSIONS

The study provided no evidence of an increased risk of PD, or increased mortalities from other causes among PQ production workers whose exposure to PQ on a daily basis was at least comparable to that of a PQ sprayer or mixer/loader.

Reasons for hospitalization and factors of mortality in patients with Parkinson's disease in the Philippines

Aim: We aimed to determine the reasons for hospitalizations and factors of mortality of Filipino Parkinson's disease (PD) patients in a tertiary hospital. Methods: We conducted a retrospective review of medical records of PD patients admitted to our institution between 2016 and 2018. Demographic and clinical data were analyzed. Results: We included 166 PD patients. The most common cause of admission was infectious (pneumonia, urinary tract, and skin-soft tissue infections) (n = 65, 39.2%). The most common cause of mortality was sepsis (n = 9, 5.4%). Renal comorbidity was a significant factor of mortality (OR: 3.67, 95% CI: 1.11-12.12; p = 0.033). Conclusion: Interventions designed to reduce the risk of complications in PD patients should be prioritized to potentially decrease the probability of eventual hospitalization.

The Promise of the Zebrafish Model for Parkinson's Disease: Today's Science and Tomorrow's Treatment

The second most prevalent neurodegenerative disorder in the elderly is Parkinson's disease (PD). Its etiology is unclear and there are no available disease-modifying medicines. Therefore, more evidence is required concerning its pathogenesis. The use of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is the basis of most animal models of PD. MPTP is metabolized by monoamine oxidase B (MAO B) to MPP + and induces the loss of dopaminergic neurons in the substantia nigra in mammals. Zebrafish have been commonly used in developmental biology as a model organism, but owing to its perfect mix of properties, it is now emerging as a model for human diseases. Zebrafish (Danio rerio) are cheap and easy to sustain, evolve rapidly, breed transparent embryos in large amounts, and are readily manipulated by different methods, particularly genetic ones. Furthermore, zebrafish are vertebrate species and mammalian findings obtained from zebrafish may be more applicable than those derived from genetic models of invertebrates such as Drosophila melanogaster and Caenorhabditis elegans. The resemblance cannot be taken for granted, however. The goal of the present review article is to highlight the promise of zebrafish as a PD animal model. As its aminergic structures, MPTP mode of action, and PINK1 roles mimic those of mammalians, zebrafish seems to be a viable model for studying PD. The roles of zebrafish MAO, however, vary from those of the two types of MAO present in mammals. The benefits unique to zebrafish, such as the ability to perform large-scale genetic or drug screens, should be exploited in future experiments utilizing zebrafish PD models.

Quality of life in Parkinson's disease: A systematic review and meta-analysis of comparative studies

BACKGROUND

Studies regarding the impact of Parkinson's disease (PD) on quality of life (QOL) have reported conflicting results, and the underlying QOL domains require further study. In order to understand the association between PD and QOL, we conducted this meta-analysis to systematically compare QOL between PD patients and healthy controls.

METHOD

The PubMed, PsycINFO, EMBASE, and Web of Science databases were systematically searched. Data were analyzed using the random-effects model.

RESULTS

Twenty studies covering 2707 PD patients and 150,661 healthy controls were included in the study. Compared with healthy controls, PD patients had significantly poorer QOL overall and in most domains with moderate to large effects sizes. Different QOL measures varied in their association with quality of life, with the Parkinson's Disease Questionnaire-39 (PDQ-39) having the largest effect size (standard mean difference, SMD = -1.384, 95% CI: -1.607, -1.162, Z = 12.189, P < 0.001), followed by the Europe Quality of Life Questionnaire-visual analogue scale (EQ-VAS) (SMD = -1.081, 95% CI: -1.578, -0.584, Z = -4.265, P < 0.001), Europe Quality of Life Questionnaire-5D (EQ-5D) (SMD = -0.889, 95% CI: -1.181, -0.596, Z = -5.962, P < 0.001), and the Short-form Health Survey (SF) scales (physical dimension: SMD = -0.826, 95% CI: -1.529, -0.123, Z = -2.303, P = 0.021; mental dimension: SMD = -0.376, 95% CI: -0.732, -0.019, Z = -2.064, P = 0.039).

CONCLUSION

PD patients had lower QOL compared with healthy controls in most domains, especially in physical function and mental health. Considering the negative impact of poor QOL on daily life and functional outcomes, effective measures should be developed to improve QOL in this population.

Increased Risk of Autopsy-Proven Pneumonia with Sex, Season and Neurodegenerative Disease

There has been a markedly renewed interest in factors associated with pneumonia, a leading cause of death worldwide, due to its frequent concurrence with pandemics of influenza and Covid-19 disease. Reported predisposing factors to both bacterial pneumonia and pandemic viral lower respiratory infections are wintertime occurrence, older age, obesity, pre-existing cardiopulmonary conditions and diabetes. Also implicated are age-related neurodegenerative diseases that cause parkinsonism and dementia. We investigated the prevalence of autopsy-proven pneumonia in the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND), a longitudinal clinicopathological study, between the years 2006 and 2019 and before the beginning of the Covid-19 pandemic. Of 691 subjects dying at advanced ages (mean 83.4), pneumonia was diagnosed postmortem in 343 (49.6%). There were 185 subjects without dementia or parkinsonism while clinicopathological diagnoses for the other subjects included 319 with Alzheimer's disease dementia, 127 with idiopathic Parkinson's disease, 72 with dementia with Lewy bodies, 49 with progressive supranuclear palsy and 78 with vascular dementia. Subjects with one or more of these neurodegenerative diseases all had higher pneumonia rates, ranging between 50 and 61%, as compared to those without dementia or parkinsonism (40%). In multivariable logistic regression models, male sex and a non-summer death both had independent contributions (ORs of 1.67 and 1.53) towards the presence of pneumonia at autopsy while the absence of parkinsonism or dementia was a significant negative predictor of pneumonia (OR 0.54). Male sex, dementia and parkinsonism may also be risk factors for Covid-19 pneumonia. The apolipoprotein E4 allele, as well as obesity, chronic obstructive pulmonary disease, diabetes, hypertension, congestive heart failure, cardiomegaly and cigarette smoking history, were not significantly associated with pneumonia, in contradistinction to what has been reported for Covid-19 disease.

Early-Onset Parkinsonism and Early-Onset Parkinson's Disease: A Population-Based Study (2010-2015)

BACKGROUND

Early-onset Parkinson's disease (EOPD), occurring between ages 40 and 55, carries social, societal, and personal consequences and may progress, with fewer comorbidities than typical, later-onset disease.

OBJECTIVE

To examine the incidence and survival of EOPD and other Parkinsonism occurring before age 55 in the population-based cohort of residents in seven Minnesota counties.

METHODS

A movement-disorder specialist reviewed all the medical records in a 2010-2015 Parkinsonism-incident cohort to confirm diagnosis and subtypes.

RESULTS

We identified 27 patients diagnosed at ≤ 50 years with incident Parkinsonism 2010-15:11 (41%) cases of EOPD, 13 (48%) drug-induced Parkinsonism, and 3 (11%) other Parkinsonism; we also identified 69 incident cases of Parkinsonism ≤ 55 years, of which 28 (41%) were EOPD, 28 (41%) DIP, and 13 (19%) other Parkinsonism. Overall incidence for Parkinsonism ≤ 50 years was 1.98/100,000 person-years, and for EOPD was 0.81/100,000 person-years. In patients ≤ 55 years, Parkinsonism incidence was 5.05/100,000 person-years: in EOPD, 2.05/100,000 person-years. Levodopa-induced dyskinesia was present in 45%of EOPD (both ≤ 50 years and ≤ 55 years). Onset of cardinal motor symptoms was proximate to the diagnosis of EOPD, except for impaired postural reflexes, which occurred later in the course of EOPD. Among the 69 Parkinsonism cases ≤ 55 years, 9 (13%; all male) were deceased (only 1 case of EOPD). Men had a higher mortality risk compared to women (p = 0.049).

CONCLUSION

The incidence of EOPD ≤ 50 years was 0.81/100,000 person-years (1.98 in Parkinsonism all type); prior to ≤ 55 years was 2.05/100,000 person-years (5.05 in Parkinsonism all type) with higher incidence in men than women. Men with Parkinsonism, all type, had higher mortality compared to women.

Ten-Year Relative Survival From the Diagnosis of Parkinson's Disease: A Nationwide Database Study

OBJECTIVES

Varying early survival rates have been reported across studies on patients with Parkinson's disease (PD). In this study, we reported the 10-year relative survival rate of patients with PD using a nationwide database.

DESIGN

This was a population-based cohort study.

SETTING AND PARTICIPANTS

We identified incident PD cases from 2004 to 2006 using the PD registration codes from the National Health Insurance Service database covering the entire South Korean population.

METHODS

Relative survival up to 10 years was evaluated by adjusting all-cause survival for expected survival, estimated from population life tables and matched by sex, age, and year of diagnosis.

RESULTS

Of the 10,159 patients with PD, 4675 (46.0%) patients survived 10 years after diagnosis. Relative survival rates decreased with time after diagnosis (0.972 after 1 year, 0.772 after 5 years, and 0.588 after 10 years). Ten-year relative survival gradually decreased with age at diagnosis. Men had a lower relative survival rate than women 2 years post diagnosis, and if they were older than 60 years.

CONCLUSIONS AND IMPLICATIONS

Patients diagnosed with PD are expected to have a lower 10-year relative survival. In the real world, patients with PD might have lower survival than the general population even in the early disease stage. Our results suggest further efforts to prevent premature mortality among patients with PD.

Medical certificate of cause of death: Looking for an European single standard

The European Union share many laws, and medical certification of cause of death standards should be probably one of them. In an analysis of medical certificates of cause of death (MCCD) from 27 countries that form or formed part of the European Union, there was considerable variability of their content. Ways to improve and harmonize the current datasets are suggested, based on what is done in different European nations, and that could be adopted elsewhere, sharing good practice. It is also suggested the need to allow the cause of death to be, at least partially, available to relatives, to help with the bereavement process and any required proceedings (which could be different to the country of issue of the certification). This common approach could reduce the risk of errors among clinicians working across different nations; it could improve information flow when decedents are transferred among distinct countries and their forms are processed; and eventually, it could help when mortality data is used to compare states.

Accuracy of death certificates for recording parkinsonian syndromes and associated dementia

INTRODUCTION

Death certification is often used to identify patients with certain diseases in epidemiologic research. There have been few studies looking at the accuracy of recording of parkinsonian diagnoses, any associated dementia and the cause of death on death certificates in people with parkinsonian conditions. This study aimed to assess this.

METHODS

Data for these analyses were derived from a prospective incident cohort of degenerative/vascular parkinsonian syndromes with lifelong follow-up from Scotland, UK (the PINE study). In those who died, the available research and clinical care records were reviewed to establish the cause for each patient's death. The sensitivity of death certificates was calculated to detect any parkinsonian diagnosis mentioned on the death certificate, the correct specific diagnosis and the presence of dementia. The causes of death were compared between clinical records and death certificates.

RESULTS

Two hundred and seventy-seven patients had died (180 men), mean age at diagnosis and death 76.9 years and 81.9 years respectively. 66.8% of death certificates mentioned any parkinsonian syndrome but only 49.5% had the correct diagnosis. Sensitivity was highest for Parkinson's disease, those who had parkinsonian-related deaths, had longer disease durations and died out of hospital. Death certificates detected 51.2% of those with dementia. The commonest causes of death were pneumonia, end-stage Parkinsonism and vascular disease with moderate agreement between case-note review and death certification.

CONCLUSION

Deaths certificates often do not mention underlying Parkinsonism or associated dementia and so epidemiological studies should not rely on this as a sole method of identifying cases or studying mortality.

Thiazolidinedione use is associated with reduced risk of Parkinson's disease in patients with diabetes: a meta-analysis of real-world evidence

BACKGROUND

The thiazolidinedione (TZD) class of oral antidiabetic agents are used to treat type 2 diabetes mellitus (DM). This meta-analysis aimed to understand the protective effect of TZD on Parkinson's disease (PD) in people with diabetes.

METHOD

A literature search was performed in PubMed, Embase, and Cochrane central from inception to until 30 September 2019. We included all real-world evidence studies assessing the use of TZD class of drugs and the risk of PD in people with diabetes. Quality of the studies was evaluated using the Newcastle-Ottawa scale. The primary outcome was the pooled hazard ratio (HR) of PD among type 2 DM TZD users as compared with TZD non-users in people with diabetes. The secondary outcome was the HR of PD among type 2 DM TZD users as compared with non-users (include both diabetic and nondiabetic population). Meta-analysis was performed using RevMan software.

RESULTS

Out of five studies selected for inclusion, four studies fulfilled the criteria for primary outcomes. The participants' mean age and follow-up duration were 66.23 ± 9.59 years and 5.25 years (2.97-7.9 years), respectively. There was a significant reduction in the risk of PD (pooled adjusted HR of 0.81 [95% CI 0.70-0.93, p = 0.004]) in TZD users compared with non-TZD users in people with diabetes. A significant protective effect of TZD was observed in Caucasian population (3 studies) (HR 0.78 (95% CI 0.66-0.92), p = 0.003).

CONCLUSION

This meta-analysis demonstrates a potential neuroprotective effect of TZD for PD risk in the population with DM.

Pneumonia risk and its associated factors in Parkinson's disease: A National Database Study

BACKGROUND

Despite pneumonia being an emerging burden on Parkinson's disease patients, there is essentially nothing known on whether they are at an increased risk of pneumonia occurrence and their associated factors.

OBJECTIVES

To determine whether Parkinson's disease is associated with the risk of pneumonia and its associated factors.

METHODS

Using nationwide database that covers the whole population in South Korea from 2002 to 2017, we identified newly diagnosed Parkinson's disease patients in 2004-2006, and selected four age- and sex-matched controls for each patient from the general population. From these patients and controls, we identified pneumonia occurrence until the end of the study period, and plotted Kaplan-Meier curves and Cox proportional hazards model to determine its risk.

RESULTS

We identified 10,159 Parkinson's disease patients and matched 39,574 controls. These patients showed a higher incidence rate than controls (11.21 vs. 3.61 events/1000 person-years) throughout the study period, and were at an increased risk of pneumonia (hazard ratio = 2.26; 95% CI, 2.17-2.36) even after adjusting for confounders. Old age, male sex, region of residence, diabetes mellitus, congestive heart failure, tuberculosis, atrial fibrillation, chronic kidney disease, cerebrovascular disease, dementia, chronic obstructive pulmonary disease, seizure disorder and antidiabetic drug usage were all associated with a higher risk of pneumonia, while dyslipidemia and antihypertensive medication usage lowered the risk.

CONCLUSIONS

Parkinson's disease patients may be more likely to experience pneumonia compared to the general population throughout the disease course from diagnosis. Therefore, physicians should focus on the modifiable risk factors of pneumonia in such patients.

Access to routinely collected health data for clinical trials - review of successful data requests to UK registries

BACKGROUND

Clinical trials generally each collect their own data despite routinely collected health data (RCHD) increasing in quality and breadth. Our aim is to quantify UK-based randomised controlled trials (RCTs) accessing RCHD for participant data, characterise how these data are used and thereby recommend how more trials could use RCHD.

METHODS

We conducted a systematic review of RCTs accessing RCHD from at least one registry in the UK between 2013 and 2018 for the purposes of informing or supplementing participant data. A list of all registries holding RCHD in the UK was compiled. In cases where registries published release registers, these were searched for RCTs accessing RCHD. Where no release register was available, registries were contacted to request a list of RCTs. For each identified RCT, information was collected from all publicly available sources (release registers, websites, protocol etc.). The search and data extraction were undertaken between January and May 2019.

RESULTS

We identified 160 RCTs accessing RCHD between 2013 and 2018 from a total of 22 registries; this corresponds to only a very small proportion of all UK RCTs (about 3%). RCTs accessing RCHD were generally large (median sample size 1590), commonly evaluating treatments for cancer or cardiovascular disease. Most of the included RCTs accessed RCHD from NHS Digital (68%), and the most frequently accessed datasets were mortality (76%) and hospital visits (55%). RCHD was used to inform the primary trial (82%) and long-term follow-up (57%). There was substantial variation in how RCTs used RCHD to inform participant outcome measures. A limitation was the lack of information and transparency from registries and RCTs with respect to which datasets have been accessed and for what purposes.

CONCLUSIONS

In the last five years, only a small minority of UK-based RCTs have accessed RCHD to inform participant data. We ask for improved accessibility, confirmed data quality and joined-up thinking between the registries and the regulatory authorities.

TRIAL REGISTRATION

PROSPERO CRD42019123088.

Stroke as a Cause of Death in Death Certificates of Patients with Dementia: A Cohort Study from the Swedish Dementia Registry

Introduction:

Patients with dementia may be at a higher risk for death from stroke. We aimed to describe characteristics of dementia patients that died from ischemic stroke (IS) in Sweden.

Methods:

A retrospective longitudinal analysis of prospectively collected data of patients registered into the Swedish Dementia Registry was conducted. Data on causes of death, drugs and comorbidities were acquired from the Swedish nationwide health registers. Deaths were attributed to stroke if the death certificate contained stroke as a cause of death and the patient had a stroke registered in Riksstroke, the Swedish Stroke Register, in the year preceding death. Demographic data at the time of dementia diagnosis was compared between patients dying from IS and registered in Riksstroke, patients dying from IS without being registered in Riksstroke and those dying from other causes.

Results:

Out of 49823 patients diagnosed with dementia between 2007 and 2014 in primary care or specialist clinics, 14170 (28.4%) had died by the end of 2014. Of these 1180 (8.3%) had IS in their death certificate, of which 459 (38.9%) had been registered in Riksstroke. In patients who died of IS the most common type of dementia was vascular dementia while those died from other causes were most often diagnosed with Alzheimer’s dementia (AD). Patients who died from IS and were registered in Riksstroke had higher MMSE score compared to other groups. Patients who died from IS took more cardiovascular medications. There were no differences in the use of antipsychotics, antidepressants, acetylcholinesterase inhibitors, memantine, anxiolytics, or hypnotics between the groups.

Conclusions:

There was a relatively high number of patients who died from IS as shown in their death certificate but had not been registered in Riksstroke in the year before death. This creates concerns on the accuracy of death certificate stroke diagnoses, particularly for deaths taking place outside hospitals.

Does Parkinson's disease increase the risk of cardiovascular events? A systematic review and meta-analysis

BACKGROUND AND PURPOSE

The impact of Parkinson's disease (PD) on the risk of cardiovascular disease is poorly known. The aim was to systematically review observational studies evaluating the association between PD and cardiovascular events.

METHODS

MEDLINE through PubMed, the Web of Science and Cochrane Central Register of Controlled Trials with conference proceedings were searched from inception to 4 July 2019. Two reviewers independently selected studies comparing cardiovascular events between Parkinson's disease and control groups. Ischaemic stroke, myocardial infarction and cardiovascular mortality were the outcomes of interest. Pooled estimates of odds ratios (ORs) and 95% confidence intervals (CIs) were derived by random effects meta-analysis. Heterogeneity was assessed using the I² test. The study protocol was registered at PROSPERO: CRD42017076527.

RESULTS

Eleven studies were included: nine cohort studies and two case-control studies. PD was associated with a significantly increased risk of stroke (nine studies: OR 1.66, 95% CI 1.19, 2.34; I²  = 50%). No significant differences were detected regarding myocardial infarction risks (eight studies: OR 1.15, 95% CI 0.72, 1.83; I²  = 76%) nor cardiovascular mortality risks (seven studies: OR 1.11, 95% CI 0.85, 1.45; I²  = 47%) in PD patients.

CONCLUSIONS

The best evidence available showed an association between PD and increased risk of stroke. The risk of myocardial infarction and cardiovascular mortality was not different in PD and non-PD individuals.

Mortality and cause of death in South Korean patients with Parkinson's disease: a longitudinal follow-up study using a national sample cohort

OBJECTIVE

The incidence rate of Parkinson's disease (PD) is growing rapidly owing to the ageing population. We investigated the mortality rates and causes of death in South Korean patients with PD.

DESIGN

We investigated a national cohort using the nationwide insurance database.

SETTING

Korean Health Insurance Review and Assessment Service-National Sample Cohort database.

PARTICIPANTS

We included 3510 participants ≥60 years of age who were diagnosed with PD between 2002 and 2013, as well as 14 040 matched controls.

INTERVENTIONS

None PRIMARY AND SECONDARY OUTCOME MEASURES: A stratified Cox proportional hazards model was used to evaluate patients with PD who were matched 1:4 with non-PD control subjects adjusted for age, sex, income and region of residence. The causes of death were grouped into 12 classifications.

RESULTS

The adjusted HR for mortality in the PD group was 2.09 (95% CI 1.94 to 2.24, p<0.001). Subgroup analysis according to age (<70 years, 70-79 years, and ≥80 years) and sex revealed that patients with PD showed higher adjusted HRs for mortality across all subgroups. Mortalities caused by metabolic, mental, neurologic, circulatory, respiratory, and genitourinary diseases, as well as trauma, were more common in the PD group than in the control group, with the highest OR observed in patients with neurologic disease.

CONCLUSIONS

We demonstrated that PD in South Korean patients ≥60 years of age was associated with increased mortality in both sexes regardless of age.

Motor and non-motor function predictors of mortality in Parkinson's disease

Doubts persist regarding the influence of Parkinson's disease (PD) on mortality. Our objective was to assess mortality rates in a prospectively followed cohort of PD patients and the impact of motor and non-motor symptoms in survival. 130 consecutive PD patients were followed during a 4-year period or until death. Baseline assessment included motor function (UPDRSIII, Hoehn and Yahr-HY), incapacity (Schwab and England-S&E, UPDRS II), Health-Related quality of life (EuroQol), non-motor symptoms (Non-Motor Symptom Scale-NMSS, MoCA, REM sleep behavior disorder symptoms questionnaire) and comorbidity burden (Charlson Comorbidity Index-CCI). These were used as predictor variables. Standardized mortality rates (SMR) were calculated, comparing with the general population. The association between mortality and predictors was tested with univariate and multivariate Cox proportional hazard regression models. Overall and gender-related SMRs were similar to the general population. SMR for pneumonia was five times higher than in the general population. Age, disease duration, CCI, EuroQol, dementia, MoCA, S&E, NMSS Hallucinations, HY, and PIGD motor phenotype were significantly associated with mortality. Adjusting for age, gender and disease duration, S&E remained significantly associated with mortality. In multivariate logistic regression analysis, death was significantly associated with disease duration, CCI and NMSS-mood/cognition scores. PD was not associated with an excess of mortality, but conferred a higher probability of dying from pneumonia. Comorbidity was a major determinant, but disease duration, baseline incapacity, cognition, psychosis, mood complaints and HRQL also contributed significantly to mortality.

Dementia and Parkinson's Disease: Similar and Divergent Challenges in Providing Palliative Care

Dementia and Parkinson's disease are incurable neurological conditions. Patients often experience specific, complex, and varying needs along their disease trajectory. Current management typically employs a multidisciplinary team approach. Recognition is growing that this team approach should also address palliative care issues to optimize quality of life for patient and family caregivers, but it remains unclear how palliative care is best delivered. To inspire future service development and research, we compare the trajectories and conceptualization of palliative care between dementia and Parkinson's disease. Both Parkinson's disease and dementia are characterized by a protracted course, with progressive but fairly insidious development of disability. However, patients with Parkinson's disease may experience relatively stable periods initially but with time, a wide range of debilitating symptoms develops, many of which do not respond well to treatment. Eventually, dementia develops in most Parkinson patients, while motor disability develops in many dementia patients. In both diseases, symptoms such as pain, apathy, sleeping problems, falls, and a high caregiver burden are prevalent. Advance care planning has benefits in terms of being prepared before the disease progresses into a stage with communication problems or severe cognitive impairment. However, for both conditions, the protracted disease trajectories complicate conceptualization of palliative care through different stages of the disease, with pertinent questions such as when to offer what interventions pro-actively. Given the similarities and differences, we should develop palliative approaches that are partially generic and partially disease-specific. These should be integrated seamlessly with disease-specific care. Substantial research is already being performed on dementia palliative care. This may also inform the further development of palliative care for Parkinson's disease, including an evaluation of palliative interventions and services.