Time trends in the prevalence and incidence of Parkinson's disease in Taiwan: A nationwide, population-based study

Use of antiviral drugs and incidence of Parkinson's disease in Taiwan

Patients infected with herpes zoster might be at risk for Parkinson's disease (PD). However, antiviral drugs may impede viral deoxyribonucleic acid (DNA) synthesis. This study aimed to determine whether the currently observed association between herpes zoster and PD is consistent with previous findings, and whether antiviral drug use is associated with PD. This retrospective cohort study used the Longitudinal Generation Tracking Database. We included patients aged 40 years and above and applied propensity score matching at 1:1 ratio for study comparability. PD risk was evaluated using Cox proportional hazards regression methods. A total of 234,730 people were analyzed. The adjusted hazard ratio (aHR) for PD in patients with herpes zoster was 1.05. Furthermore, the overall incidence of PD was lower in those treated with antiviral drugs than in the untreated ones (3.17 vs. 3.76 per 1,000 person-years); the aHR was 0.84. After stratifying for sex or age, a similar result was observed. In conclusion, herpes zoster may increase the risk of PD, particularly among females, but receiving antiviral treatment reduces the risk by 16%. Therefore, using antiviral drugs may help prevent PD. However, additional research is required to determine the underlying mechanism(s).

Proprioceptive and olfactory deficits in individuals with Parkinson disease and mild cognitive impairment

BACKGROUND

Individuals with neurodegenerative diseases such as Parkinson disease (PD) and Alzheimer's (AD) disease often present with perceptual impairments at an early clinical stage. Therefore, early identification and quantification of these impairments could facilitate diagnosis and early intervention.

OBJECTIVES

This study aimed to compare proprioceptive and olfactory sensitivities in individuals diagnosed with PD and mild cognitive impairment (MCI).

METHODS

Proprioception in the forearm and olfactory function were measured in neurotypical older adults, individuals with PD, and individuals with MCI. Position and passive motion senses were assessed using a passive motion apparatus. The traditional Chinese version of the University of Pennsylvania smell identification test (UPSIT-TC) and the smell threshold test (STT) were used to identify and discriminate smell, respectively.

RESULTS

Position sense threshold between the groups differed significantly (p < 0.001), with the PD (p < 0.001) and MCI (p = 0.004) groups showing significantly higher than the control group. The control group had significantly higher mean UPSIT-TC scores than the PD (p < 0.001) and MCI (p = 0.006) groups. The control group had a significantly lower mean STT threshold than the PD and MCI groups (p < 0.001 and p = 0.008, respectively). UPSIT-TC scores significantly correlated with disease progression in PD (r = - 0.50, p = 0.008) and MCI (r = 0.44, p = 0.04).

CONCLUSIONS

Proprioceptive and olfactory sensitivities were reduced in individuals with PD and MCI, and these deficits were related to disease severity. These findings support previous findings indicating that perceptual loss may be a potential biomarker for diagnosing and monitoring disease progression in individuals with neurodegenerative diseases.

Update: Descriptive epidemiology of Parkinson disease

We review the descriptive epidemiology of Parkinson disease (PD). PD is a prevalent neurologic disorder in high Socio-Demographic Index (SDI) nations with rising prevalence in low and middle SDI nations. PD became a prevalent disorder in high SDI nations during the 20th century. Population growth, population aging, and increased disease duration are major drivers of rising PD prevalence. Exposure to industrial toxicants may also be a contributor to rising PD prevalence. PD is an age-related disorder with incidence likely peaking in the 8th decade of life and prevalence in the 9th decade of life. PD is notable for significant sex difference in PD risk with greater risk in men. There may be ancestral differences in PD prevalence and risk. PD is associated with moderately increased mortality though this may be underestimated. Despite significant research, there is considerable uncertainty about basic features of PD epidemiology.

Use of dipeptidyl peptidase-4 inhibitors was associated with a lower risk of Parkinson's disease in diabetic patients

Diabetes mellitus is a risk factor for Parkinson's disease (PD). While animal studies have supported the benefits of incretin-based therapies, including dipeptidyl peptidase-4 (DPP4) inhibitors, in PD, clinical research has yielded controversial results. This cohort study aimed to assess the relationship between PD incidence and the utilization of DPP4 inhibitor in diabetic patients. Using Taiwan's National Health Insurance Research Database from 2009 to 2018, diabetic patients receiving metformin plus at least one second-line oral antidiabetic (OAD) were enrolled. The patients were categorized as DPP4 inhibitor users and non-users. Propensity score matching was employed to establish a 1:1 ratio between DPP4 inhibitor users and non-users. Among the 205,910 patients enrolled, 149 were diagnosed with PD during follow-up. The incidence rate was 0.29 per 1000 person-years for DPP4 inhibitor users and 0.55 per 1000 person-years for the non-users. DPP4 inhibitor users exhibited a significantly lower risk of PD (adjusted hazard ratio, 0.51; 95% CI 0.39-0.68). Among DPP4 inhibitor users, vildagliptin showed the strongest correlation with a reduction in the risk of PD. This study demonstrates that the use of DPP4 inhibitors along with metformin in diabetic patients is associated with a lower risk of PD compared to those using other OADs.

Early detection of Parkinson's disease: Systematic analysis of the influence of the eyes on quantitative biomarkers in resting state electroencephalography

While resting state electroencephalography (EEG) provides relevant information on pathological changes in Parkinson's disease, most studies focus on the eyes-closed EEG biomarkers. Recent evidence has shown that both eyes-open EEG and reactivity to eyes-opening can also differentiate Parkinson's disease from healthy aging, but no consensus has been reached on a discriminatory capability benchmark. The aim of this study was to determine the resting-state EEG biomarkers suitable for real-time application that can differentiate Parkinson's patients from healthy subjects under both eyes closed and open. For this, we analysed and compared the quantitative EEG analyses of 13 early-stage cognitively normal Parkinson's patients with an age and sex-matched healthy group. We found that Parkinson's disease exhibited abnormal excessive theta activity in eyes-closed, which was reflected by a significantly higher relative theta power, a higher time percentage with a frequency peak in the theta band and a reduced alpha/theta ratio, while Parkinson's patients showed a significantly steeper non-oscillatory spectral slope activity than that of healthy subjects. We also found considerably less alpha and beta reactivity to eyes-opening in Parkinson's disease plus a significant moderate correlation between these EEG-biomarkers and the MDS-UPDRS score, used to assesses the clinical symptoms of Parkinson's Disease. Both EEG recordings with the eyes open and reactivity to eyes-opening provided additional information to the eyes-closed condition. We thus strongly recommend that both eyes open and closed be used in clinical practice recording protocols to promote EEG as a complementary non-invasive screening method for the early detection of Parkinson's disease, which would allow clinicians to design patient-oriented treatment and improve the patient's quality of life.

Exploring the Link between Chronic Kidney Disease and Parkinson's Disease: Insights from a Longitudinal Study Using a National Health Screening Cohort

Chronic kidney disease (CKD) and Parkinson's disease (PD) are common illnesses found in the geriatric population. A potential link between CKD and PD emergence has been hypothesized; however, existing conclusions are disputed. In this longitudinal research, we analyzed data acquired from the Korean National Health Insurance Service-Health Screening Cohort. The dataset comprised the health information of 16,559 individuals clinically diagnosed with CKD and 66,236 control subjects of comparable ages, all aged ≥40 years. These subjects participated in health examinations from 2002 to 2019. To assess the correlation between CKD and PD, we employed overlap-weighted Cox proportional hazard regression models. The unadjusted, crude hazard ratio for PD was greater in the CKD group than in the control group (crude hazard ration (HR) 1.20; 95% confidence interval (CI) = 1.04-1.39; p = 0.011). However, the Cox proportional hazard regression analysis, incorporating propensity score overlap weighting, revealed no significant discrepancy after considering confounding variables such as demographic factors, socio-economic status, lifestyle, and concurrent health conditions (adjusted HR (aHR), 1.09; 95% CI = 0.97-1.22; p = 0.147). Subgroup analyses showed a higher probability of PD development among certain CKD individuals, including those who resided in rural areas (aHR, 1.19; 95% CI = 1.03-1.37; p = 0.022), maintained a normal weight (aHR, 1.29; 95% CI = 1.08-1.56; p = 0.006), or had fasting blood glucose levels ≥100 mg/dL (aHR, 1.18; 95% CI = 1.00-1.39; p = 0.046). Therefore, these clinical or environmental factors may influence the incidence of PD in CKD patients. In conclusion, our results suggest that the general CKD population may not exhibit a greater propensity for PD than their non-CKD counterparts. However, this might be contingent upon specific lifestyle and comorbid conditions. Thus, certain lifestyle alterations could be crucial in mitigating the potential manifestation of PD in patients diagnosed with CKD.

Sequential change in olfaction and (non) motor symptoms: the difference between anosmia and non-anosmia in Parkinson's disease

Introduction

Hyposmia is a common prodrome in patients with Parkinson's disease (PD). This study investigates whether olfactory changes in PD differ according to the degree of olfactory dysfunction and whether there are changes in motor and non-motor symptoms.

Methods

The 129 subjects with PD were divided into two groups: anosmia and non-anosmia. All cases were reassessed within 1-3 years after the initial assessment. The assessment included the MDS-Unified PD Rating Scale (MDS-UPDRS), the University of Pennsylvania Smell Identification Test (UPSIT), Beck's Depression Inventory-II (BDI-II), Montreal Cognitive Assessment (MoCA), and equivalence dose of daily levodopa (LEDD). The generalized estimating equation (GEE) model with an exchangeable correlation structure was used to analyze the change in baseline and follow-up tracking and the disparity in change between these two groups.

Results

The anosmia group was older and had a longer disease duration than the non-anosmia group. There was a significant decrease in UPSIT after follow-up in the non-anosmia group (β = -3.62, p < 0.001) and a significant difference in the change between the two groups (group-by-time effect, β = 4.03, p < 0.001). In the third part of the UPDRS motor scores, there was a tendency to increase the score in the non-anosmia group compared to the anosmia group (group-by-time effect, β = -4.2, p < 0.038). There was no significant difference in the group-by-time effect for UPDRS total score, LEDD, BDI-II, and MoCA scores.

Discussion

In conclusion, this study found that olfactory sensation may still regress in PD with a shorter disease course without anosmia, but it remains stable in the anosmia group. Such a decline in olfaction may not be related to cognitive status but may be associated with motor progression.

The Rehabilitative Effect of Archery Exercise Intervention in Patients with Parkinson's Disease

Background

Archery exercise exerts a rehabilitative effect on patients with paraplegia and might potentially serve as complementary physiotherapy for patients with Parkinson's disease.

Objective

This study aimed to examine the rehabilitative effects of an archery intervention.

Methods

A randomized controlled trial of a 12-week intervention was performed in patients with idiopathic Parkinson's disease. Thirty-one of the 39 eligible patients recruited from a medical center in Taiwan participated in the trial, of whom 16 were in the experimental group practicing archery exercises and 15 were in the control group at the beginning; twenty-nine completed the whole process. The Purdue pegboard test (PPT), the Unified Parkinson's Disease Rating Scale I to III (UPDRS I to III), physical fitness test, and timed up and go test (TUG) were used to assess the intervention effects of archery exercise.

Results

Compared to the control group, the outcome differences between the posthoc and baseline tests in PPT, UPDRS I to III, lower extremity muscular strength, and TUG in the experimental group (between-group difference in difference's mean: 2.07, 1.59, 1.36, -2.25, -3.81, -9.10, 3.57, and -1.51, respectively) did show positive changes and their effect sizes examined from Mann-Whitney U tests (η: 0.631, 0.544, 0.555, 0.372, 0.411, 0.470, 0.601, and 0.381, respectively; Ps < 0.05) were medium to large, indicating that the archery intervention exerted promising effects on improving hand flexibility and finger dexterity, activity functions in motor movement, lower extremity muscular strength, and gait and balance ability.

Conclusions

Traditional archery exercise was suggested to have a rehabilitative effect for mild to moderate Parkinson's disease and could be a form of physiotherapy. Nevertheless, studies with larger sample sizes and extended intervention periods are needed to ascertain the long-term effects of archery exercise.

25-year trends in first-time hospitalizations for Parkinson's disease and subsequent mortality: A Danish nationwide cohort study

BACKGROUND

In most countries, incidence and mortality for Parkinson's disease (PD) have not been monitored by surveillance registries, although it could demonstrate the need for primary and tertiary prevention.

OBJECTIVE

To examine 25-year trends in first-time hospitalizations for PD in Denmark and subsequent short and long-term mortality.

METHODS

In a nationwide population-based cohort we identified all 34,947 individuals with a first-time hospitalization for PD from 1995 through 2019. We calculated standardized incidence rates of PD and 1-year and 5-year mortality by sex. Mortality rates were compared with a reference cohort randomly selected from the background population matched on sex, age, and index date.

RESULTS

The annual standardized incidence rate of PD was relatively stable during the study period in both men and women. The incidence of PD was higher in men than in women and with the highest incidence in those aged 70-79 years. One and 5-year mortality risk after first-time hospitalization for PD was similar for men and women, and decreased by around 30% and 20%, respectively, between 1995 and 2019. The matched reference cohort had a similar decline in mortality over time.

CONCLUSION

The rate of first-time hospitalization for PD was relatively stable between 1995 and 2019, whereas subsequent short and long-term mortality declined during the period as in the reference cohort.

[Trends in Prevalence of Parkinson's Disease in German General and Neurological Practices from 2010 to 2019]

Hintergrund Bis 2040 wird mit einer erheblichen Prävalenzzunahme der Parkinson-Erkrankung und damit einhergehend mit einer erheblichen Belastung der Versorgungssysteme gerechnet. Ziel der Studie war es deshalb, eine Veränderung der Anzahl an Parkinson-Patienten bereits im Zeitraum 2010 bis 2019 in deutschen Haus- und neurologischen Facharztpraxen zu untersuchen.

Methode Die vorliegende Querschnittstudie basiert auf den Daten von 411 Hausarzt- (HA) und 56 neurologischen Facharzt-Praxen (FA) aus der IQVIA Disease Analyzer Datenbank. Die Anzahl der etablierten und neu diagnostizierten Patienten mit Parkinson-Erkrankung wurde in den Jahren 2010 und 2019 mit Alters- und Geschlechtsstruktur und der Anteil therapierten Patienten untersucht.Ergebnisse Die Zahl der Parkinson-Patienten veränderte sich geringfügig zwischen 2010 bis 2019 von 3352 (0,36% aller Patienten) auf 3541 (0,33%) in den HA-Praxen und von 4976 (3,48%) auf 4826 (3,34%) in den FA-Praxen. Die Anzahl der neu diagnostizierten Fälle fiel bei den HA-Praxen leicht von 862 (0,09% aller Patienten) auf 836 (0,08%) und bei den FA-Praxen von 1818 (1,27%) auf 1372 (0,95% aller Patienten). Der Anteil an Frauen unter allen Parkinson-Erkrankten sank sowohl in HA- und FA- Praxen von 52,0% bzw. 50,2% auf 47,3% bzw. 46,0%. Das Durchschnittsalter stieg bei den HA-Praxen von 77,1 (SD 10,4) im Jahr 2010 auf 77,7 (SD 9,3) Jahre im Jahr 2019 und in FA-Praxen von 74,6 (SD 9,9) auf 75,8 (SD 9,9) Jahre.

Diskussion Die prognostizierte Zunahme von Parkinson-Patienten in der ambulanten Versorgung lässt sich für den Zeitraum 2010 bis 2019 nicht bestätigen. Es gab jedoch eine Verschiebung der Altersstruktur zu höheren Altersgruppen und eine Verringerung des Anteils an Frauen mit einer Parkinson-Erkrankung. Neben ätiologischen Erklärungen sollten Besonderheiten des Versorgungssystems und methodische Limitationen berücksichtigt werden.

Cost-effectiveness of the add-on exenatide to conventional treatment in patients with Parkinson’s disease when considering the coexisting effects of diabetes mellitus

Objective

This study aims to investigate the cost-effectiveness of the add-on exenatide to conventional pharmacotherapy in patients with Parkinson’s disease (PD) when considering the coexistence of diabetes mellitus (DM).

Methods

We used the Keelung and Community-based Integrated Screening databases to understand the medical utilisation in the Hoehn and Yahr stages of patients with PD. A Markov model with 1-year cycle length and 50-year time horizon was used to assess the cost-effectiveness of add-on exenatide to conventional pharmacotherapy compared to conventional pharmacotherapy alone. All costs were adjusted to the value of the new Taiwanese dollar (NT$) as of the year 2020. One-way sensitivity and probability analyses were performed to test the robustness of the results.

Results

From a societal perspective, the add-on exenatide brought an average of 0.39 quality-adjusted life years (QALYs) gained, and a cost increment of NT$104,744 per person in a 50-year horizon compared to conventional pharmacotherapy. The incremental cost-effectiveness ratio (ICER) was NT$268,333 per QALY gained. As the ICER was less than the gross domestic product per capita (NT$839,558), the add-on exenatide was considered to be very cost-effective in the two models, according to the World Health Organization recommendation. Add-on exenatide had a 96.9% probability of being cost-effective in patients with PD, and a 100% probability of being cost-effective in patients with PD and DM.

Conclusion

Add-on exenatide is cost-effective in PD combined with DM. Considering that DM may be a risk factor for neurodegenerative diseases, exenatide provides both clinical benefits and cost-effectiveness when considering both PD and DM.

Change in the incidence of Parkinson's disease in a large UK primary care database

Parkinson's disease (PD) has the fastest rising prevalence of all neurodegenerative diseases worldwide. However, it is unclear whether its incidence has increased after accounting for age and changes in diagnostic patterns in the same population. We conducted a cohort study in individuals aged ≥50 years within a large UK primary care database between January 2006 and December 2016. To account for possible changes in diagnostic patterns, we calculated the incidence of PD using four case definitions with different stringency derived from the combination of PD diagnosis, symptoms, and treatment. Using the broadest case definition, the incidence rate (IR) per 100,000 person years at risk (PYAR) was 149 (95% CI 143.3-155.4) in 2006 and 144 (95% CI 136.9-150.7) in 2016. In conclusion, the incidence of PD in the UK remained stable between 2006 and 2016, when accounting for age and diagnostic patterns, suggesting no major change in underlying risk factors for PD during this time period in the UK.

A nationwide study of the incidence, prevalence and mortality of Parkinson's disease in the Norwegian population

Epidemiological studies of Parkinson's disease (PD) show variable and partially conflicting findings with regard to incidence, prevalence, and mortality. These differences are commonly attributed to technical and methodological factors, including small sample sizes, differences in diagnostic practices, and population heterogeneity. We leveraged the Norwegian Prescription Database, a population-based registry of drug prescriptions dispensed from Norwegian pharmacies to assess the incidence, prevalence, and mortality of PD in Norway. The diagnosis of PD was defined based on the prescription of dopaminergic drugs for the indication of PD over a continuous time. During 2004-2017, 12,229 males and 9831 females met our definition for PD diagnosis. PD prevalence increased over the observation period, with larger changes observed in the older age groups. Incidence and prevalence of PD increased with age, peaking at 85 years. The male/female prevalence ratio was 1.5 across all ages, whereas the incidence ratio increased with age, from 1.4 in those 60 years, to 2.03 among those >90 years. While PD mortality was generally higher than that of the general population, mortality odds ratios decreased with age, approaching 1.0 among individuals >90 years old. When adjusted for the sex-specific mortality of the general population, the mortality among females with PD was equal to or higher than the mortality among males with PD. Our findings demonstrate that the epidemiological features of PD, including sex-differences, are age and time-period dependent and indicate that sex differences in PD mortality are unlikely to stem from disease-specific negative impact of survival in males.

Recalling the pathology of Parkinson's disease; lacking exact figure of prevalence and genetic evidence in Asia with an alarming outcome: A time to step-up

Parkinson's disease (PD) is the second most common and progressive neurodegenerative disease globally, with major symptoms like bradykinesia, impaired posture, and tremor. Several genetic and environmental factors have been identified but elucidating the main factors have been challenging due to the disease's complex nature. Diagnosis, prognosis, and management of such diseases are challenging and require effective targeted attention in developing countries. Recently, PD is growing rapidly in many crowded Asian countries as an alarming threat with inadequate knowledge of its prevalence, genetic architecture, and geographic distribution. This study gave an in-depth overview of the prevalence, incidence and genomic/genetics studies published so far in the Asian population. To the best of our knowledge, PD has increased significantly in several Asian countries, including China, South Korea, Japan, Thailand, and Israel over the past few years, requiring a greater level of care and attention. Genetic screening of families with PD at national levels and establishing an official database of PD cases are essential to get a comprehensive and conclusive view of the exact prevalence and genetic diversity of PD in the Asian population to properly manage and treat the disease.

Associations of Chinese Herbal Medicine Usage with Risk of Dementia in Patients with Parkinson's Disease: A Population-Based, Nested Case-Control Study

Background: Patients who have Parkinson's disease (PD) comorbid with dementia is common. With the prolonged life expectancy, dementia is gradually becoming prevalent and affects most patients' life qualities. However, the efficacy of current treatments in dementia of PD is limited. Previous studies indicated the potential roles of Chinese herbal medicine (CHM) in treating dementia, yet the correlation between CHM usage and risk of dementia in PD patients is unclear. Methods: This case-control study was nested within a National Health Insurance database of patients over 50 years with newly diagnosed PD from year 2000 to 2010. Among these PD patients, dementia and nondementia groups were discussed, respectively, in terms of the duration of taking CHM (≥90 vs. <90 days), age (50-64 vs. ≥65 years) and gender. Results: The risk of dementia in patients with PD is lower in CHM users compared with non-CHM users, especially in those taking CHM for more than 90 days (adjusted odds ratio [aOR] 0.58; 95% confidence interval [95% CI] 0.39-0.87). The use of CHM was significantly related to the lower risk of dementia in the subgroups of patients with age ≥65 years for CHM usage <90 days (aOR 0.68; 95% CI 0.53-0.88), patients with age ≥65 years for CHM usage ≥90 days (aOR 0.63; 95% CI 0.42-0.94), female patients using CHM for ≥90 days (aOR 0.43; 95% CI 0.22-0.84), and male patients using CHM for <90 days (aOR 0.62; 95% CI 0.43-0.88). Conclusions: The authors demonstrated the association of CHM usage with lower risk of dementia in patients with PD, especially in women with the usage of CHM for more than 90 days. Since no arbitrary causal conclusions could be drawn from retrospective cohort studies, the finding in this study could be used to generate a hypothesis for a subsequent design of prospective longitudinal study.

Identifying incident Parkinson's disease using administrative diagnostic codes: a validation study

BACKGROUND

Administrative databases that capture diagnostic codes are increasingly being used worldwide for research because they can save time and reduce costs. However, assessing validity is necessary before defining diseases using only diagnostic codes in research applications.

OBJECTIVE

Our objective was to assess the validity of using diagnostic codes to identify incident Parkinson's disease (PD) cases in Olmsted County, Minnesota using an established standard for comparison (1976-2005).

METHODS

Cases were identified solely using computer programs applied to administrative diagnostic code indexes from the Rochester Epidemiology Project (REP). Two codes >30 days apart or one code on the death certificate constituted PD. The standard was a clinical diagnosis by movement disorders specialists based on medical record review. Validity was assessed using positive predictive value (PPV) and sensitivity. Numbers of incident cases and incidence rates were compared between the two ascertainment methods by sex.

RESULTS

The codes only method over-counted the number of incident PD cases by 73% (804 versus 464), and this over-counting generally increased with calendar year. Sensitivity was 80% (95% CI [76%, 84%]) and PPV was 46% (95% CI [34%, 50%]). Disease status misclassification accounted for two-thirds of falsely identified cases, where individuals were found to not have PD (43%) or even parkinsonism (23%) after medical record review. The codes only method also over-estimated the incidence rate time trend for men and women by approximately two-fold.

CONCLUSION

In our context, using administrative diagnostic codes only to identify incident PD cases is not recommended unless more accurate algorithms are developed.

Trends in the incidence and prevalence of Parkinson's disease in Korea: a nationwide, population-based study

BACKGROUND

The lack of adequate and detailed epidemiological data of Parkinson's disease (PD), especially in Asia, is a barrier to future disease burdens and the prospect of effective public health plans. This study aimed to investigate temporal trends in the incidence and prevalence of PD in South Korea from 2010 to 2015, based on uniform diagnostic criteria.

METHODS

This study examined all PD patients registered in a South Korean national registry database of more than 50 million individuals. We analyzed the incidence and prevalence of PD according to age, gender, and region.

RESULTS

The annual incidence of PD was between 22.4-27.8 cases per 100,000 individuals. During the 6-year study period, there were 73,726 new PD patients, 42.3% of whom were men. The standardized incidence of PD increased over time in men but remained constant in women until 2013 but began to increase in 2014. The female-to-male ratio in the incidence of PD was 1.4:1 while the female-to-male ratio in the prevalence of PD was 1.6:1. The age- and gender-standardized prevalence of PD increased from 115.9 cases per 100,000 individuals in 2010 to 139.8 cases per 100,000 individuals in 2015. From 2014, the incidence and prevalence of PD peaked in individuals aged between 80 and 89 years in both men and women. Regional analysis also showed an increased prevalence of PD in all regions of Korea.

CONCLUSIONS

The incidence and prevalence of PD in Korea were higher in women and increased gradually from 2010 to 2015. The findings may contribute to epidemiological studies of PD in Asia, and may provide clues on risk factors for PD.

Prevalence and incidence of Parkinson's disease and drug-induced parkinsonism in Korea

Background

Parkinson’s disease (PD) and drug-induced parkinsonism (DIP) are the major diseases of parkinsonism. To better understand parkinsonism, we aimed to assess the prevalence and incidence of PD and DIP in Korea from 2012 to 2015.

Methods

We used the Health Insurance Review and Assessment Service database, which covers the entire population in Korea. We used claims during 2011–2015 to assess epidemiology of PD and DIP during 2012–2015. Retrospective cross-sectional study design was employed to assess prevalence, whereas retrospective cohort study design was used to determine incidence. Patients with at least one claim with ICD-10 G20 and who received antiparkinsonian drugs for at least 60 days were classified as having PD. We excluded patients with antiparkinsonian drugs that can be used for indications other than PD. Patients with at least one claim with ICD-10 G211 or G251 during the prescription period of drugs that are frequently related with DIP were classified as having DIP. Incident cases had a disease-free period of 1 year before diagnosis. To evaluate the significance of changes in the prevalence or incidence over time, Poisson regression was used to determine p for trend.

Results

The prevalence of PD increased from 156.9 per 100,000 persons in 2012 to 181.3 per 100,000 persons in 2015 (p for trend< 0.0001). The incidence of PD decreased steadily from 35.4 per 100,000 person-years in 2012 to 33.3 per 100,000 person-years in 2015 (p for trend< 0.0001). The prevalence of DIP increased from 7.3 per 100,000 persons in 2012 to 15.4 per 100,000 persons in 2015 (p for trend< 0.0001) and the incidence of DIP increased from 7.1 per 100,000 person-years in 2012 to 13.9 per 100,000 person-years in 2015 (p for trend< 0.0001).

Conclusions

Our study suggests that the incidence of PD has gradually decreased whereas, the incidence of DIP increased from 2012 to 2015. Further studies are warranted to examine possible causes of increased DIP incidence in order to develop management strategy for parkinsonism.

Parkinson Matters

Recent epidemiological observations have drawn attention to the rapid rise in the burden caused by Parkinson's disease over the past years, emphasizing that Parkinson's disease is a matter of serious concern for our future generations. A recent report by Public Health England corroborates this message, by providing new insight on trends in deaths associated with neurological diseases in England between 2001 to 2014. The report indicates that mortality associated with Parkinson's disease and related disorders increased substantially between 2001 and 2014. This trend is partially explained by increased longevity in the population. However, it is possible that changes in exposure to risk factors, recent improvements in multidisciplinary care (leading to prolonged survival), and improved diagnostic awareness or improved registration also influenced the observed trend. Furthermore, patients with Parkinson's disease and related disorders were found to die at an advanced age, and the majority die in a care home or hospital, despite a preponderant preference for many patients and their families to spend their last days at home. To combat these concerning observations, future efforts should be focused on providing resources for vulnerable elderly Parkinson patients, avoiding unplanned hospital admissions and out-of-home deaths as much as possible. Possible solutions include a community-based network of specifically trained allied health therapists, personal case managers for Parkinson patients, dedicated Parkinson nursing homes, and improved centralised support services from university clinics to regional community hospitals aimed at facilitating optimal wide-scale care delivery.

Antiviral Therapy in Patients With Chronic Hepatitis C Is Associated With a Reduced Risk of Parkinsonism

BACKGROUND

The risk of parkinsonism after antiviral treatment against chronic hepatitis C (CHC) is unclear.

OBJECTIVES

To investigate the association between CHC and parkinsonism and the efficacy of antiviral therapy.

METHODS

Using the National Health Insurance Research Database of Taiwan from 2004 to 2012, patients with and without CHC, patients receiving pegylated interferon-based antiviral therapy, and those without such therapy were matched by age, gender, and comorbidities by propensity scores and followed for new diagnoses of parkinsonism and Parkinson's disease (PD). Multivariable Cox proportional hazards regression analyses were performed.

RESULTS

Overall, 49,342 patients with CHC were matched with 49,342 non-CHC patients. After adjustment for confounding factors, there was a significantly increased risk (31%) of parkinsonism (hazard ratio [HR] 1.306; 95% confidence interval [CI], 1.208-1.412) in those with CHC and the risk of parkinsonism requiring anti-Parkinson medication (HR 1.323; 95% CI, 1.214-1.441). Furthermore, 23,647 untreated CHC patients were matched with 23,647 patients receiving antiviral therapy. Patients receiving antiviral therapy had a significantly lower risk of developing parkinsonism (38%; HR 0.618; 95% CI, 0.498-0.765) and a reduced risk of parkinsonism requiring anti-Parkinson medication (HR 0.651; 95% CI, 0.515-0.823). In sensitivity analyses, antiviral therapy significantly reduced the risk of parkinsonism and PD after adjustment for detection, selection, disease latency biases, and competing mortality. Our results suggest successful antiviral therapy associates with a reduced risk of hepatitis C virus-related parkinsonism compared with those with treatment failure.

CONCLUSIONS

CHC infection is associated with an increased risk of parkinsonism or PD. Antiviral therapy against CHC is associated with a reduced risk of parkinsonism or PD. © 2019 International Parkinson and Movement Disorder Society.

Dementia-Related Functional Disability in Moderate to Advanced Parkinson's Disease: Assessment Using the World Health Organization Disability Assessment Schedule 2.0

Dementia is a common nonmotor condition among people with moderate or advanced Parkinson’s disease (PD). Undoubtedly, profound motor symptoms cause remarkable impairment in daily activities; however, dementia-related disabilities have not been thoroughly investigated, especially not with consideration of differences according to sex. The present study used the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) to compare the functional disability between men and women with PD (PwP) with and without dementia. This study employed a registry of disability evaluation and functional assessment using the Taiwan Data Bank of Persons with Disability between July 2012 and October 2018. To investigate dementia-related disability in PwP, 1:1 matching by age and Hoehn-Yahr stage was conducted, which resulted in the inclusion of 1605 study participants in each group. The present study demonstrated that among the six major domains of WHODAS 2.0, the section of “Getting alone with others” was significantly worse in both genders of PwP with dementia; however, a greater disability in fulfilling activities of daily living was only noted in male PwP with dementia but not in their female counterparts. Neither the inability to provide self-care nor participation were significantly different between the sexes. Our findings suggested that deteriorating social relationships were a dementia-related disability in all PwP at the moderate and advanced disease stages. Regarding the performance of activities of daily living, deterioration was related to dementia only in male PwP. Such disabilities could indicate cognitive impairment in people with moderate or advanced PD and could be used as an indicator for the early detection of dementia in PwP by healthcare professionals through the easier functional assessment of the WHODAS 2.0.

Bipolar disorder and risk of Parkinson disease: A nationwide longitudinal study

OBJECTIVE

To evaluate the risk of Parkinson disease (PD) among patients with bipolar disorder (BD).

METHODS

Using the Taiwan National Health Insurance Research Database, we examined 56,340 patients with BD and 225,360 age- and sex-matched controls between 2001 and 2009 and followed them to the end of 2011. Individuals who developed PD during the follow-up period were identified.

RESULTS

Patients with BD had a higher incidence of PD (0.7% vs 0.1%, p < 0.001) during the follow-up period than the controls. A Cox regression analysis with adjustments for demographic data and medical comorbid conditions revealed that patients with BD were more likely to develop PD (hazard ratio [HR] 6.78, 95% confidence interval [CI] 5.74-8.02) than the control group. Sensitivity analyses after exclusion of the first year (HR 5.82, 95% CI 4.89-6.93) or first 3 years (HR 4.42; 95% CI 3.63-5.37) of observation showed consistent findings. Moreover, a high frequency of psychiatric admission for manic/mixed and depressive episodes was associated with an increased risk of developing PD.

CONCLUSION

Patients with BD had a higher incidence of PD during the follow-up period than the control group. Manic/mixed and depressive episodes were associated with an elevated likelihood of developing PD. Further studies are necessary to investigate the underlying pathophysiology between BD and PD.

Incidence and prevalence of 121 rare diseases in China: Current status and challenges

In order to ascertain the current status of and challenges posed by the incidence and prevalence of rare diseases in China, this study teases out data on the incidence and prevalence of 121 rare diseases listed in China's First List of Rare Disease to provide rationales and references for the development and promotion of rare-disease-related policies. The National Health Commission of the People's Republic of China issued the Rare Disease Diagnosis and Treatment Guide (2019) (denoted here as China's Rare Disease Diagnosis and Treatment Guide), which cited data on the incidence/prevalence of 21 rare diseases (21 of 121 rare diseases, 17.36%). Data on 68 diseases (56.20%) were found in monographs, literature databases, and official websites. Data on the incidence/prevalence of 70 diseases were compiled, though no data were available for the 51 remaining diseases. There are published data on the incidence/prevalence of only 14 diseases at the national level. Sources of data on the incidence and prevalence of rare diseases mainly include cases counts from hospitals (40.56%), other sources of data (24.48%), screening (20.98%), cross-sectional studies (8.39%), and estimates from models (7.69%). Data on the incidence/prevalence of rare diseases in China are limited and typically lack accuracy, uniformity, and timeliness. Epidemiological data at the national level are greatly lacking, and data are not amenable to comparison. China recently initiated epidemiological studies of rare diseases at the national and regional level. The country will continue to promote, use, and update its list of common rare diseases, actively encourage the coding and registration of cases of rare diseases, and take actions to collect, share, and use that information.

Cardiovascular risk factors and Parkinson's disease in 500,000 Chinese adults

OBJECTIVE

The objectives of this study were to compare the risks of Parkinson's disease among those with versus those without prior stroke or heart disease at baseline in a prospective study of 0.5 million adults in China, and to examine associations of cardiovascular disease risk factors (cigarette smoking, hypertension, diabetes, obesity) with risk of Parkinson's disease.

METHODS

During an average of 11.5 years of follow-up of 503,497 middle-aged participants in the China Kadoorie Biobank study, 603 incident cases were hospitalized with a diagnosis of Parkinson's disease. Cox proportional hazards models were used to assess associations of history of heart disease or stroke with Parkinson's disease in all participants, and of cardiovascular disease risk factors with Parkinson's disease in a subset without prior cardiovascular disease.

RESULTS

In this population the incidence rate of Parkinson's disease (mean [SD] age of cases, 61 [10] years) was 13.3 (95% confidence interval: 12.3-14.4) per 100,000 person-years. Incidence increased with age, and was higher in men than in women, and in urban than in rural residents. Prior stroke was associated with about twofold higher risk of Parkinson's disease (hazard ratio 1.94; 1.39-2.69). After adjustment for confounders in those without prior cardiovascular disease, a 5 kg/m2 higher body mass index was associated with 17% (1.17; 1.03-1.34: P = 0.019) higher risk of Parkinson's disease, but neither hypertension, diabetes, nor current cigarette smoking was significantly associated with Parkinson's disease.

INTERPRETATION

Prior stroke and adiposity were each associated with higher risks of Parkinson's disease, but none of the other cardiovascular disease risk factors were significantly associated with Parkinson's disease in this population.

[Trends in the Prevalence of Dementia and Parkinson's Disease: An Analysis Based on Health Claims Data from all German Statutory Health Insurance Funds for Persons aged 65+in Germany 2009-2012]

OBJECTIVES

There will be an increase in the number of people with dementia (DEM) and Parkinson's disease (PD) with the ageing of the population. The aim of the study was to calculate prevalences and trends of prevalences for DEM and PD in Germany to enable reliable public health planning.

METHODS

For the years 2009-2012, sex-specific period prevalences of DEM and PD for 5-year age-groups based on health claims data from all German statutory health insurance funds were calculated. Time trends were estimated using a negative binomial regression.

RESULTS

In 2012 and for persons aged 65 or older, the crude prevalence was 7.9% for DEM and 2.2% for PD. Between 2009 and 2012, a mean decrease of the DEM prevalence by 1.2% per year was found for women and men above age 65. For PD we found constant rates between 2009-2012 among men and an annual mean decrease of PD prevalence of 0.5% among women.

CONCLUSION

A reduction of the DEM prevalence by 1.2% per year could partially counterbalance the increase of people with dementia resulting from ageing population. For PD we found decreasing prevalences only among women.

More than an "inverted-U"? An exploratory study of the association between the catechol-o-methyltransferase gene polymorphism and executive functions in Parkinson's disease

Executive dysfunction is common in Parkinson's disease (PD) patients. The catechol-O-methyltransferase (COMT) Val158Met polymorphism has been proposed to affect executive functions (EFs) in the prefrontal cortex. The present study attempted to explore the influence of the COMT polymorphism on EFs in patients with PD. Fifty-four PD patients were recruited and underwent neuropsychological assessments for three core EFs. The COMT polymorphism was genotyped using the TaqMan SNP Genotyping Assay. Participants were divided into three study groups: Val homozygotes, heterozygotes, and Met homozygotes. The three COMT genotype groups had significantly different performances in set-shifting [χ2 (2, 54) = 9.717, p = 0.008] and working memory tasks [χ2 (2, 54) = 7.806, p = 0.020]. Post-hoc analyses revealed that PD Val homozygotes performed significantly poorer in the set-shifting task than did either the PD Met homozygotes (z = -2.628, p = 0.009) or PD heterozygotes (z = -2.212, p = 0.027). Our explorative results suggest that the putative level of prefrontal dopamine influenced set-shifting through a "cane-shaped" dopamine level-response relationship. Our results have clinical implications, which may influence PD treatment with dopamine in the future because the optimal dopamine level to maximize EFs may vary based on the clinical course and COMT polymorphism status. Further study recruiting a larger number of participants is needed to confirm our preliminary findings.

Time Trends of the Incidence, Prevalence, and Mortality of Parkinsonism

Objectives:We assessed trends in the incidence, prevalence, and post-diagnosis mortality of parkinsonism in Ontario, Canada over 18 years. We also explored the influence of a range of risk factors for brain health on the trend of incident parkinsonism.Methods:We established an open cohort by linking population-based health administrative databases from 1996 to 2014 in Ontario. The study population comprised residents aged 20–100 years with an incident diagnosis of parkinsonism ascertained using a validated algorithm. We calculated age- and sex-standardized incidence, prevalence, and mortality of parkinsonism, stratified by young onset (20–39 years) and mid/late onset (≥40 years). We assessed trends in incidence using Poisson regression, mortality using negative binomial regression, and prevalence of parkinsonism and pre-existing conditions (e.g., head injury) using the Cochran–Armitage trend test. To better understand trends in the incidence of mid/late-onset parkinsonism, we adjusted for various pre-existing conditions in the Poisson regression model.Results:From 1996 to 2014, we identified 73,129 incident cases of parkinsonism (source population of ∼10.5 million), of whom 56% were male, mean age at diagnosis was 72.6 years, and 99% had mid/late-onset parkinsonism. Over 18 years, the age- and sex-standardized incidence decreased by 13.0% for mid/late-onset parkinsonism but remained unchanged for young-onset parkinsonism. The age- and sex-standardized prevalence increased by 22.8%, while post-diagnosis mortality decreased by 5.5%. Adjustment for pre-existing conditions did not appreciably explain the declining incidence of mid/late-onset parkinsonism.Conclusion:Young-onset and mid/late-onset parkinsonism exhibited differing trends in incidence over 18 years in Ontario. Further research to identify other factors that may appreciably explain trends in incident parkinsonism is warranted.

Large-Scale Assessment of Function and Disability in Patients with Parkinson's Disease Using the Functioning Disability Evaluation Scale-Adult Version

This study assesses the functioning and disability related to Parkinson's disease using the Functioning Disability Evaluation Scale-Adult Version (FUNDES-Adult), based on the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) in a large-scale database; this study describes, discusses and clarifies the predictive factor of not being in an ambulatory status. Of 7455 patients included in this study, 3561 were not ambulatory and 3894 were ambulatory or assisted ambulatory. Patients with poor walking status revealed higher FUNDES-Adult scores in all domains. Age, modified Hoehn⁻Yahr stage, living in an institution and the standardized score of FUNDES-Adult domains 1 and 2 were positive independent predictors of the not ambulatory status. The FUNDES-Adult could evaluate multifaceted disability and predict the walking status in patients with Parkinson's disease.

The increasing prevalence of Parkinson's disease in Estonia

OBJECTIVES

A previous epidemiological study of Parkinson's disease (PD) in the county of Tartu, Estonia, found an adjusted prevalence rate of 152/100 000 persons. We aimed to determine PD prevalence almost 20 years later, as well as evaluate any dynamic changes in disease frequency compared to the first study.

METHODS

A cross-sectional, community-based study was conducted over 2010-2016 in the county of Tartu, Estonia. Multiple case-finding sources, including information from neurologists, family doctors, the local PD Society, nursing institutions, and the database of the Estonian Health Insurance Fund were used to identify patients with PD of all ages.

RESULTS

Total crude PD prevalence was 283 and age-adjusted prevalence (standardized to the 2014 age structure of the Estonian population) 314/100 000. No significant differences in age-adjusted prevalence rates were found between men and women, nor people living in urban and rural areas. After adjustment to the same standard population used in the previous prevalence study, the overall age-adjusted prevalence rate was 197/100 000. Patients in the current study were older and often had a more severe form of PD and a longer disease duration, compared to those reported in the first epidemiological study 20 years ago.

CONCLUSIONS

The age-specific crude rates in oldest age-groups have risen substantially, and the age-adjusted prevalence has moderately increased compared to 20 years ago in Estonia. We hypothesize that the increased life expectancy of the Estonian population and improved diagnosis of PD contributed most to the increase in disease frequency.

Dental Scaling Decreases the Risk of Parkinson's Disease: A Nationwide Population-Based Nested Case-Control Study

The protective effect of dental scaling in Parkinson’s disease (PD) remains inconclusive. The aim of this study was to analyze the association between dental scaling and the development of PD. A retrospective nested case-control study was performed using the National Health Insurance Research Database of Taiwan. The authors identified 4765 patients with newly diagnosed PD from 2005 to 2013 and 19,060 individuals without PD by matching sex, age, and index year. In subgroup 1, with individuals aged 40–69 years, individuals without periodontal inflammatory disease (PID) showed a protective effect of dental scaling against PD development, especially for dental scaling over five consecutive years (adjusted odds ratio = 0.204, 95% CI = 0.047–0.886, p = 0.0399). In general, the protective effect of dental scaling showed greater benefit for individuals with PID than for those without PID, regardless of whether dental scaling was performed for five consecutive years. In subgroup 2, with patients aged ≥70 years, the discontinued (not five consecutive years) scaling showed increased risk of PD. This was the first study to show that patients without PID who underwent dental scaling over five consecutive years had a significantly lower risk of developing PD. These findings emphasize the value of early and consecutive dental scaling to prevent the development of PD.

Does nephrotic syndrome without chronic kidney disease increase the risk of Parkinson's disease and secondary parkinsonism? A nationwide population-based study in Taiwan

OBJECTIVES

Previous research has shown that patients with nephrotic syndrome (NS) have a higher risk of cognitive impairment, dementia or neurodegenerative disorder. The present study aimed to examine a relationship, if any exists between NS and Parkinson's disease (PD), a neurodegenerative disorder and secondary parkinsonism (sPS).

METHODS

A nationwide retrospective observational study conducted using data from the 2000-2010 Taiwan National Health Insurance Research Database. This study included 3663 patients with NS and 14 652 randomly selected, age-matched and sex-matched patients without NS. A Cox multivariable proportional hazards model was used to evaluate the risk of PD and sPS (PDsPS) in the NS cohort.

RESULTS

This study identified a positive association between NS and the risk of PDsPS in both men and women and in all age groups (adjusted HR 1.51; 95% CI 1.37 to 1.66). Compared with patients without NS and comorbidities, those with NS with two or more comorbidities exhibited an 8.23-fold higher risk of PDsPS (95% CI 6.22 to 10.9) and patients with NS and one comorbidity exhibited a 2.93-fold higher risk of PDsPS (95% CI 2.37 to 3.63).

CONCLUSIONS

Patients with NS have an increased risk of PDsPS. This increased risk may be related to brain vascular damage or blood-brain barrier impairment. Further research is necessary to explore the underlying relationship between NS and PDsPS.

High exposure compared with standard exposure to metoclopramide associated with a higher risk of parkinsonism: a nationwide population-based cohort study

AIMS

We conducted a cohort study utilizing a nationwide health insurance database to assess the European Medicines Agency's restrictions on using metoclopramide and its association with the risk of parkinsonism.

METHODS

New oral metoclopramide users aged ≥20 years, and age- and gender-matched non-users were recruited between 2001 and 2011. Users were divided into high-exposure (dose >30 mg day^-1 and/or duration >5 days) and standard-exposure (dose ≤30 mg day^-1 and duration ≤5 days) groups. The adjusted hazard ratio (aHR) with 95% confidence interval (CI) estimated the risk of parkinsonism.

RESULTS

During a 1-year period, 122 of 218 931 (0.06%) users of metoclopramide vs. 56 of 218 931 (0.03%) non-users developed parkinsonism (P < 0.001). Among the 122 cases of parkinsonism in users, 64 (0.04%) were from 168 566 standard-exposure users and 58 (0.12%) from 50 365 high-exposure users. Compared with non-users, the risk of parkinsonism was higher in users (aHR 2.16; 95% CI 1.54, 3.02), including standard-exposure (aHR 1.73; 95% CI 1.11, 2.70), and high-exposure (aHR 3.15; 95% CI 1.78, 5.57) users. High-exposure users had a higher risk of parkinsonism than standard-exposure users (aHR 1.83; 95% CI 1.28, 2.63). Within the high-exposure group, 45 233 of 50 365 (89.81%) users and 55 of 58 (94.83%) parkinsonism were from long-duration exposure; 5 132 of 50 365 (10.19%) users and 3 of 58 (5.17%) parkinsonism were from high-dose exposure and long-duration + high-dose exposure.

CONCLUSIONS

The risk of parkinsonism in metoclopramide users, although extremely low (0.06%), is 2.16-fold greater than in non-users. High-exposure users have a 1.83-fold higher risk than standard-exposure users. As users in high-exposure group had a higher risk of parkinsonism than in standard-exposure group, and the majority of users and parkinsonism in high-exposure group were from long-duration exposure; thus, physician are advised to avoid prescribing metoclopramide for >5 days, even if the daily dose is ≤30 mg.

The Role of Gene Editing in Neurodegenerative Diseases

Neurodegenerative diseases (NDs), at least including Alzheimer's, Huntington's, and Parkinson's diseases, have become the most dreaded maladies because there are no precise diagnostic tools or definite treatments for these debilitating diseases. The increased prevalence and a substantial impact on the social-economic and medical care of NDs propel governments to develop policies to counteract the impact. Although the etiologies of NDs are still unknown, growing evidence suggests that genetic, cellular, and circuit alternations may cause the generation of abnormal misfolded proteins, which uncontrolledly accumulate to damage and eventually overwhelm the protein-disposal mechanisms of these neurons, leading to a common pathological feature of NDs. If the functions and the connectivity can be restored, alterations and accumulated damages may improve. The gene-editing tools including zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats-associated nucleases (CRISPR/CAS) have emerged as a novel tool not only for generating specific ND animal models for interrogating the mechanisms and screening potential drugs against NDs but also for the editing sequence-specific genes to help patients with NDs to regain function and connectivity. This review introduces the clinical manifestations of three distinct NDs and the applications of the gene-editing technology on these debilitating diseases.

PBPK/PD assessment for Parkinson's disease risk posed by airborne pesticide paraquat exposure

Exposure to several specific pesticides has led to an increase of Parkinson's disease (PD) risk. However, it is difficult to quantify the PD population risk related to certain pesticides in regions where environmental exposure data are scarce. Furthermore, the time trend of the prevalence and incidence of PD embedded in the background relationship between PD risk and pesticide exposures has not been well characterized. It has been convincingly identified that a key pesticide associated significantly with an increased risk trend of PD is paraquat (PQ). Here, we present a novel, probabilistic population-based exposure-response approach to quantify the contribution from PQ exposure to prevalence risk of PD. We found that the largest PQ exposure contributions occurred in its positive trend during 2004-2011, with the PQ contributing nearly 21 and 24%, respectively, to the PD prevalence rates among the age groups of 70-79 and ≥ 80 years in Taiwan. We also employed the present population risk model to predict the PQ-induced PD prevalence based on the projected rates of increase in PQ exposure associated with age-specific population. The predicted outcome can be used as an early warning signal for public health authorities. We suggest that a mechanistic understanding of the contribution of a specific pesticide exposure to PD risk trends is crucial to enhance our insights into the perspective on the impacts of environmental exposure on the neurodegenerative diseases.

Epidemiology of Parkinson's Disease-East Versus West

Background

The cause of PD at present remains unknown. A number of epidemiological studies have been conducted across the globe to ascertain the disease burden and the possible risk factors. In this review, we analyze the various studies from East and West with an aim to observe the important similarities and differences in the disease occurrence and risk factor profile.

Methods

A comprehensive search of descriptive and analytical epidemiological studies was undertaken. The descriptive studies and meta-analysis providing the standardised population rates were selected. The demographics, ethnicity and geographical differences between East and West were analysed. In analytical epidemiology, more established and well-studied non-genetic risk factors for PD were reviewed utilising the prospective cohort studies, case control studies and meta-analysis where available.

Results and Conclusion

PD is more common with increasing age and shows male predominance, which is more obvious in Western studies. The PD prevalence and incidence rates are slightly lower in the East compared to the West. Incidence studies on different ethnic populations in the same country have also found a lower occurrence of PD amongst Easterners compared to Westerners. Setting methodological differences aside, studies from East and West suggest a role for both environmental and genetic risk factors in PD causation. Smoking, caffeine intake and pesticide exposure are well-established risk factors across regions. There is a robust data for dairy product consumption, urate levels and physical activity in the West while studies on certain risk factors like head injury and alcohol show conflicting and mixed results.

Periodontal inflammatory disease is associated with the risk of Parkinson's disease: a population-based retrospective matched-cohort study

Background

The cause−effect relation between periodontal inflammatory disease (PID) and Parkinson’s disease (PD) remains uncertain. The purpose of our study was to investigate the association between PID and PD.

Methods

We conducted a retrospective matched-cohort study by using Taiwan’s National Health Insurance Research Database. We identified 5,396 patients with newly diagnosed PID during 1997–2004 and 10,792 cases without PID by matching sex, age, index of year (occurrence of PID), and comorbidity. Cox proportional hazard regression was used to evaluate the risk of subsequent PD.

Results

At the final follow-up, a total of 176 (3.26%) and 275 (2.55%) individuals developed PD in the case and control groups, respectively. Patients with PID have a higher risk of developing PD (adjusted hazard ratio = 1.431, 95% CI [1.141–1.794], p = 0.002).

Discussion

Our results show that PID is associated with an increased risk of developing PD. Whilst these findings suggest that reducing PID may modify the risk of developing PD, further study will be needed.

Impact of Sjogren's syndrome on Parkinson's disease: A nationwide case-control study

Objective

To investigate whether Sjogren’s syndrome would have an influence on the development of Parkinson’s disease.

Methods

A population-based case-control study was conducted. Participants consisted of 7716 subjects with newly diagnosed Parkinson’s disease and a population of 75129 matched control subjects between 2000 and 2010. We measured the risk of Parkinson’s disease in association with Sjogren’s syndrome by using adjusted odds ratios.

Results

A total of 143 Parkinson’s disease subjects (1.9%) and 893 control subjects (1.2%) suffered from Sjogren’s syndrome (p < 0.001). The crude odds ratio for Parkinson’s disease among subjects with Sjogren’s syndrome was 1.56 (95% CI 1.30–1.86; p < 0.01). After adjustment for potential confounders which have been proposed that would increase the risk of development of Parkinson’s disease, Sjogren’s syndrome was found to be significantly associated with the risk of Parkinson’s disease with an odds ratio of 1.37 (95% CI 1.15–1.65; p < 0.01).

Conclusion

This study preliminarily proposed that Sjogren’s syndrome was significant associated with an increased risk of Parkinson’s disease.

Increase in Parkinson's disease-related mortality among males in Northern Italy

BACKGROUND

According to standard mortality statistics based on the underlying cause of death (UCOD), mortality from Parkinson's disease (PD) is increasing in most European countries. However, mortality trends are better investigated taking into account all the diseases reported in the death certificate (multiple causes of death approach, MCOD).

METHODS

All deaths of residents in the Veneto Region (Northern Italy) aged≥45 years with any mention of PD were extracted from 2008 to 2015. The Annual Percent Change (APC) in age-standardized mortality rates was computed both for PD as the UCOD, and by MCOD. The association with common chronic comorbidities and acute complications was investigated by log-binomial regression. The frequency of the mention of PD in death certificates was investigated through linkage with an archive of patients with a previous clinical diagnosis of the disease.

RESULTS

PD was reported in 2.1% of all deaths, rising from 1.9% in 2008 to 2.4% in 2015. Among males, age-standardized rates increased over time both in analyses based on the UCOD (APC +4.1%; Confidence Interval +1.5%,+6.7%), and on MCOD (APC +2.2%; +0.2,+4.2%). Among females time trends were not significant. Mention of PD was associated with that of dementia/Alzheimer and acute infectious diseases. Among known PD patients, the disease was reported only in 60.2% of death certificates.

CONCLUSIONS

Mortality associated to PD is steeply increasing among males in Northern Italy; further investigations on time trends for PD, both through all available electronic health archives and clinical studies, should be set as a priority for epidemiological research.

Epidemiology of Parkinson's disease

Parkinson's disease (PD) affects 1-2 per 1000 of the population at any time. PD prevalence is increasing with age and PD affects 1% of the population above 60 years. The main neuropathological finding is α-synuclein-containing Lewy bodies and loss of dopaminergic neurons in the substantia nigra, manifesting as reduced facilitation of voluntary movements. With progression of PD, Lewy body pathology spreads to neocortical and cortical regions. PD is regarded as a movement disorder with three cardinal signs: tremor, rigidity and bradykinesia. A recent revision of the diagnostic criteria excludes postural instability as a fourth hallmark and defines supportive criteria, absolute exclusion criteria and red flags. Non-motor symptoms in PD have gained increasing attention and both motor and non-motor signs are now included among the supportive criteria. The cause of PD is unknown in most cases. Genetic risk factors have been identified, including monogenetic causes that are rare in unselected populations. Some genetic factor can be identified in 5-10% of the patients. Several environmental factors are associated with increased risk of PD. Autopsy studies show that the clinical diagnosis of PD is not confirmed at autopsy in a significant proportion of patients. Revised diagnostic criteria are expected to improve the clinician´s accuracy in diagnosing PD. Increasing knowledge on genetic and environmental risk factors of PD will probably elucidate the cause of this disease within the near future.

Association between History of Dental Amalgam Fillings and Risk of Parkinson's Disease: A Population-Based Retrospective Cohort Study in Taiwan

The impact of dental amalgam on the development of Parkinson's disease (PD) is still uncertain, although a positive association between dental amalgam and PD has been found in a few case-control studies. The patients with amalgam fillings restored between 2000 and 2008 were identified by using the National Health Insurance Research Database (NHIRD) in Taiwan. The same number of patients who had no new amalgam filling restored was matched by sex, age, and treatment date. Both cohorts were followed up from the treatment date until the date of diagnosis of PD, death, or the end of the year 2008. The individuals who received amalgam fillings had a significantly higher risk of PD afterward (adjusted hazard ratio [HR]=1.583, 95% confidence interval [CI]=1.122-2.234, p=0.0089) than those who did not. In the individuals who received amalgam fillings, being diagnosed with diabetes or hyperlipidemia demonstrated a significantly lower HR of PD occurrence than in the patients without diabetes or hyperlipidemia (HR=0.449, 95% CI=0.254-0.794, p=0.0059; HR=0.445, 95% CI=0.260-0.763, p=0.0032) after adjusting for comorbidities and Charlson-Deyo Comorbidity Index (CCI) scores. Meanwhile, hypertension increased the hazard risk of PD (HR=1.645, 95% CI=1.098-2.464, p=0.0159). The patients exposed to dental amalgam fillings were 1.583 times more likely to have PD afterward compared to their non-exposed counterparts after adjusting for comorbidities and CCI scores.

The biomarkers of immune dysregulation and inflammation response in Parkinson disease

Parkinson's disease (PD) is referring to the multi-systemic α-synucleinopathy with Lewy bodies deposited in midbrain. In ageing, the environmental and genetic factors work together and overactive major histocompatibility complex pathway to regulate immune reactions in central nerve system which resulting in neural degeneration, especially in dopaminergic neurons. As a series of biomarkers, the human leukocyte antigen genes with its related proteomics play cortical roles on the antigen presentation of major histocompatibility complex molecules to stimulate the differentiation of T lymphocytes and i-proteasome activities under their immune response to the PD-related environmental alteration and genetic variation. Furthermore, dopaminergic drugs change the biological characteristic of T lymphatic cells, affect the α-synuclein presentation pathway, and inhibit T lymphatic cells to release cytotoxicity in PD development. Taking together, the serum inflammatory factors and blood T cells are involved in the immune dysregulation of PD and inspected as the potential clinic biomarkers for PD prediction.

National Trends of Antiparkinsonism Treatment in Taiwan: 2004-2011

Background. Several guidelines for Parkinson's disease (PD) management were recently updated. We examined temporal trends for antiparkinsonism drugs in Taiwan. Methods. Antiparkinsonism prescriptions, including levodopa, ergot/nonergot dopamine agonists (DAs), amantadine, selegiline, entacapone, and anticholinergics, were identified in the Taiwan National Health Insurance Database from 2004 to 2011. Time trend analyses were estimated assuming Poisson distribution. Results. A total of 19,302 PD patients in 2004 and 41,606 PD patients in 2011 were analyzed. Antiparkinsonism prescriptions increased significantly from 187,137 in 2004 to 414,587 in 2011. Levodopa monotherapy or combination therapy was the mainstay. Levodopa monotherapy comprised 37.4% of prescriptions in 2004 and 44.2% in 2011, with an annual increase rate of 18.14%. There was a substantially increasing trend of DA prescriptions, which were higher in younger-aged patients (<60 years) than in older-aged group (p = 0.0006). Among combination therapy, DA combined with levodopa or other antiparkinsonism medications became the main combinations for younger-aged patients after 2009. After 2005, the proportion of ergot DA usage markedly decreased and PD patients using nonergot DA increased. Conclusions. Levodopa was the major treatment from 2004 to 2011. There was a steeply increased trend of DA use, especially in younger-aged patients. Nonergot agents comprised the major DA group after 2005.

Variations in Incidence and Prevalence of Parkinson's Disease in Taiwan: A Population-Based Nationwide Study

Demographic, socioeconomic, and urbanization level variations in Parkinson's disease (PD) are rarely investigated, especially in Asia. This study describes an eight-year trend in PD incidence and prevalence in Taiwan as well as assessing the effects of sociodemographics and urbanization on the incidence and prevalence of PD. The data analyzed were acquired from the Taiwan National Health Insurance Research Database (NHIRD) entries between 2002 and 2009. The calendar year, sex, and age-specific rates were standardized, and the effects of the sociodemographics and urbanization on PD were assessed using Poisson regression analysis. PD incidence and prevalence showed a significantly increasing trend, with a greater magnitude noted for prevalence than for incidence (87.3% versus 9.2%). The PD incidence and prevalence increased with age and were slightly higher in men than in women. The people who were not under the labor force (i.e., dependents) or with lower monthly incomes were at significantly increased adjusted incidence rate ratio (1.50–1.56) and adjusted prevalence rate ratio (1.66–1.71) of PD. Moreover, significantly higher PD incidence and prevalence were noted in areas with lesser urbanization. This information emphasizes the need for preventive and clinical care strategies targeting the segment of Taiwanese population that exhibited a greater incidence and prevalence of PD.