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

Risk of Parkinson's disease-related death in cancer survivors: A population-based study in Japan

BACKGROUND

The risk of Parkinson's disease (PD)-related death in patients with cancer largely unexplored.

METHODS

We analyzed data from the Neoplasms ANd other causes of DEath (NANDE) study, which investigates the causes of death in patients with cancer in Japan. Standardized mortality ratios (SMRs) were calculated to compare the risk of PD-related deaths in patients with cancer to that of the general population. Poisson regression models were employed to estimate the relative risk of PD-related death in the subgroups.

RESULTS

The cohort included 548,485 patients with cancer, yielding 2,047,398 person-years at risk from 1995 to 2013. During the study period, 242,250 patients died and 145 deaths were attributable to PD. The SMR for PD-related death was 2.34 (95% confidence interval [CI]: 1.99-2.75). Patients who were diagnosed with cancer before 70 years of age had a high SMR (>5) for PD-related deaths. The SMR of patients with mouth-to-stomach cancers (lip, oral cavity, pharynx, esophagus, and stomach cancers) was 3.72 (95% CI: 2.84-4.86), while that of those with other cancers was 1.93 (95% CI: 1.57-2.37). The multivariate Poisson regression model revealed that patients with mouth-to-stomach cancers were more likely to die of PD than those without (relative risk 2.07, 95 % CI; 1.46-2.93).

CONCLUSIONS

Patients with cancer are at a high risk of PD-related death; particularly, mouth-to-stomach cancers and potentially obstructing medication for PD are attributable to a high mortality risk. Careful management, including adequate PD treatment, would benefit cancer survivors with PD and reduce the risk of PD-related death.

The Potentiality of Natural Products and Herbal Medicine as Novel Medications for Parkinson's Disease: A Promising Therapeutic Approach

As the global population ages, the prevalence of Parkinson's disease (PD) is steadily on the rise. PD demonstrates chronic and progressive characteristics, and many cases can transition into dementia. This increases societal and economic burdens, emphasizing the need to find effective treatments. Among the widely recognized causes of PD is the abnormal accumulation of proteins, and autophagy dysfunction accelerates this accumulation. The resultant Lewy bodies are also commonly found in Alzheimer's disease patients, suggesting an increased potential for the onset of dementia. Additionally, the production of free radicals due to mitochondrial dysfunction contributes to neuronal damage and degeneration. The activation of astrocytes and the M1 phenotype of microglia promote damage to dopamine neurons. The drugs currently used for PD only delay the clinical progression and exacerbation of the disease without targeting its root cause, and come with various side effects. Thus, there is a demand for treatments with fewer side effects, with much potential offered by natural products. In this study, we reviewed a total of 14 articles related to herbal medicines and natural products and investigated their relevance to possible PD treatment. The results showed that the reviewed herbal medicines and natural products are effective against lysosomal disorder, mitochondrial dysfunction, and inflammation, key mechanisms underlying PD. Therefore, natural products and herbal medicines can reduce neurotoxicity and might improve both motor and non-motor symptoms associated with PD. Furthermore, these products, with their multi-target effects, enhance bioavailability, inhibit antibiotic resistance, and might additionally eliminate side effects, making them good alternative therapies for PD treatment.

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).

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.

Longitudinal follow-up study of the association with gout and Alzheimer's disease and Parkinson's disease in Korea

To date, no clear conclusion on the relationships of gout with the occurrence of typical neurodegenerative diseases, Alzheimer's disease (AD) and Parkinson's disease (PD), has been reached. This study aimed to determine whether the patients with gout are at a lower or higher probability of developing AD or PD than those without gout. Longitudinal follow-up data of a representative sample of Korean adults were assessed. 18,079 individuals diagnosed with gout between 2003 and 2015 were enrolled in the gout group. The comparison group comprised 72,316 demographics-matched individuals not diagnosed with gout. Longitudinal associations of gout with AD or PD were estimated using Cox proportional hazard regression adjusting for potential confounders. The adjusted hazard ratios (HRs) of AD and PD in the gout group were 1.01 and 1.16 times higher than controls, but these differences were not statistically significant (95% confidence interval [CI] = 0.92-1.12 and 95% CI = 0.97-1.38, respectively). Although there was no significant association in the entire sample, AD and PD probabilities in patients with gout were significantly higher in participants < 60 years, and PD probabilities in patients with gout were significantly higher in overweight participants. Our findings identify significant correlations of gout with AD and PD in participants < 60 years and gout with PD in those with overweight, indicating that gout may play a role in the development of neurodegenerative diseases in younger or overweight populations. Further investigations should be performed to corroborate these findings.

Parkinson's disease clinical milestones and mortality

Identification of factors predicting and driving mortality in PD is important for patient information, disease management, and design of future clinical trials. This study included newly diagnosed PD patients and normal controls (NC) from a population-based study with repeated assessments over a 10-year period. We used the Kaplan–Meier method to estimate survival, Cox proportional hazards regression models to identify baseline risk factors of mortality, and Cox regression models with time-dependent covariates to evaluate the impact of four clinical milestones of advanced PD (visual hallucinations, recurrent falls, dementia, and nursing home placement) on mortality risk. During the 10-year study, 65 (34.2%) of 190 patients and 25 (12.3%) of 203 NC died, with an unadjusted hazard ratio (HR) of 2.85 (95% CI 1.80–4.52) and a HR of 2.48 (95% CI 1.55–3.95) when adjusted for confounders, including comorbidities. Higher age, more severe motor impairment, and postural instability-gait difficulty (PIGD) phenotype were independent baseline predictors of mortality. Each clinical milestone alone more than doubled the risk of death and had a cumulative effect on mortality, with a HR of 10.83 (95% CI 4.39–26.73) in those experiencing all four milestones. PD patients have an increased mortality risk that is disease-related and becomes evident early during the course of the disease. While motor severity and PIGD phenotype were early risk factors of mortality, clinical milestones signaled a substantially increased risk of death later during the disease course, highlighting their potential significance in clinical disease staging and prognosis.

Causes of Mortality in Korean Patients with Neurodegenerative Dementia

The prevalence of neurodegenerative dementia is increasing owing to the rapid growth of the older population. We investigated risks and causes of mortality in Korean patients with neurodegenerative dementia using data from the Korean Health Insurance Review and Assessment Service-National Sample Cohort with the aim to improve their care. From a pool of 1,125,691 patients, 11,215 patients aged ≥60 years who were diagnosed with dementia between 2002 and 2013 were examined along with 44,860 matched controls. A Cox proportional hazard model was used to calculate crude and adjusted hazard ratios (HRs). During the follow-up period, 34.5% and 18.8% of individuals in the neurodegenerative dementia and control groups, respectively, died (P < 0.001). The adjusted HR for mortality in the neurodegenerative dementia group was 2.11 (2.41 and 1.96 in men and women, respectively). Moreover, the adjusted HRs in patients with neurodegenerative dementia were 3.25, 2.77, and 1.84 for those diagnosed at ages 60–69, 70–79, and ≥80 years, respectively. The highest odds ratio for mortality was noted among patients with neurologic disease (15.93) followed by those with mental disease (4.89). These data show that the risk of mortality increased regardless of age and sex in Korean patients with neurodegenerative dementia.

The Association of Pre-existing Diagnoses of Alzheimer’s Disease and Parkinson’s Disease and Coronavirus Disease 2019 Infection, Severity and Mortality: Results From the Korean National Health Insurance Database

Objectives

Despite the numerous studies on coronavirus disease 2019 (COVID-19), data regarding the impact of pre-existing diagnoses of Alzheimer’s disease (AD) and Parkinson’s disease (PD) on the susceptibility to and outcome of COVID-19 are limited. We aimed to determine whether patients with AD/PD had a higher likelihood of contracting COVID-19 and experiencing worse outcomes.

Methods

Data from patients with confirmed diagnoses of COVID-19 (n = 8,070) from January to June 2020 and control participants (n = 121,050) who were randomly selected to match the patients on the basis of age and sex were extracted from the Korean National Health Insurance Database. Pre-existing diagnoses of AD and PD were identified based on medical claim codes. The associations of pre-existing AD or PD with contracting COVID-19, developing severe COVID-19 and dying due to COVID-19 were examined using a logistic regression model. The participants’ age, sex, income, comorbidity score, and history of hypertension/diabetes were assessed as covariates.

Results

COVID-19 cases were more likely to have a pre-existing AD diagnosis (adjusted odds ratio [aOR] = 2.11, 95% confidence interval [CI] = 1.79–2.50, P-value < 0.001) than controls. COVID-19 cases were more likely to have a pre-existing PD diagnosis than controls, although this estimate did not quite reach statistical significance (aOR = 1.41, 95% CI = 1.00–2.00, P-value = 0.054). Pre-existing AD was related to severe disease and mortality from COVID-19 (aOR = 2.21, 95% CI = 1.64–2.98; aOR = 2.21, 95% CI = 1.00–2.00). Pre-existing PD was not associated with mortality (aOR = 1.54, 95% CI = 0.75–3.16) but was associated with severe disease (aOR = 2.89, 95% CI = 1.56–5.35).

Conclusion

We found that COVID-19 infection was significantly associated with a pre-existing diagnosis of AD but not with a pre-existing diagnosis of PD. Patients with pre-existing AD had higher odds of developing severe COVID-19 and dying. Pre-existing PD was only associated with a higher odds of developing severe COVID-19.

The Occurrence of Alzheimer's Disease and Parkinson's Disease in Individuals With Osteoporosis: A Longitudinal Follow-Up Study Using a National Health Screening Database in Korea

Background: Public health concerns regarding the potential link between osteoporosis and the increased occurrence of Alzheimer’s disease (AD) and Parkinson’s disease (PD) have been raised, but the results remain inconsistent and require further validation. Here, we investigated the long-term relationship of osteoporosis with the occurrence of AD/PD using data from a large-scale nationwide cohort.

Methods: This longitudinal follow-up study included 78,994 patients with osteoporosis and 78,994 controls from the Korean National Health Insurance Service-Health Screening Cohort database (2002–2015) who were matched using propensity score matching at a 1:1 ratio based on age, sex, income, and residential area. A Cox proportional hazard model was used to assess the association between osteoporosis and the occurrence of AD/PD after adjusting for multiple covariates.

Results: During the follow-up period, AD occurred in 5,856 patients with osteoporosis and 3,761 controls (incidence rates: 10.4 and 6.8 per 1,000 person-years, respectively), and PD occurred in 1,397 patients and 790 controls (incidence rates: 2.4 and 1.4 per 1,000 person-years, respectively). The incidences of AD and PD were significantly higher in the osteoporosis group than in the matched control group. After adjustment, the osteoporosis group exhibited 1.27-fold and 1.49-fold higher occurrences of AD (95% confidence interval (CI) = 1.22–1.32) and PD (95% CI = 1.36–1.63) than the controls, respectively. The results of subgroup analyses supported the increased occurrence of AD and PD in patients with osteoporosis, independent of income, residential area, obesity, smoking, alcohol consumption, hyperlipidemia, hypertension, or blood glucose level.

Conclusion: Our results indicate that the presence of osteoporosis may increase the likelihood of developing two common neurodegenerative diseases in adults aged ≥40 years.

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.

Cardiovascular and cerebrovascular risk markers in Parkinson's disease: Results from a case-control study

BACKGROUND

The relationship between Parkinson's disease (PD) and cardiovascular and cerebrovascular disease is not yet well established. Recent data suggest an increased risk of myocardial infarction and stroke in PD patients. Therefore, we designed a study to assess surrogate markers of cardiovascular and cerebrovascular risk in PD.

METHODS

We conducted a case-control study comparing PD patients recruited from a Movement Disorders Unit with controls randomly invited from a primary healthcare center. All participants underwent a detailed clinical evaluation, including medical history, physical assessment, carotid ultrasound, blood and urine analysis, and 24-h ambulatory blood pressure monitoring. The primary outcome was the carotid intima-media thickness (CIMT).

RESULTS

We included 102 participants in each study arm. No significant difference was found in the CIMT among groups (MD: 0.01, 95% CI: -0.02, 0.04). Carotid plaques were more frequent in PD patients (OR: 1.90, 95% CI: 1.02, 3.55), although the lipid profile was more favorable in this group (LDL MD: -18.75; 95% CI: -10.69, -26.81). Nocturnal systolic blood pressure was significantly higher in PD patients (MD: 4.37, 95% CI: 0.27, 8.47) and more than half of the PD patients were non-dippers or reverse dippers (OR: 1.83, 95% CI: 1.04, 3.20).

CONCLUSION

We did not find a difference in CIMT between PD and controls. A higher frequency of carotid plaques and abnormal dipper profile supports the hypothesis that PD patients are not protected from cardiovascular and cerebrovascular disease.

The Association between Anemia and Parkinson's Disease: A Nested Case-Control Study Using a National Health Screening Cohort

(1) Background: Controversy exists regarding the relationship between anemia and Parkinson's disease (PD). This study aimed to evaluate the risk of PD related to anemia in the Korean population. (2) Methods: The Korean National Health Insurance Service-National Sample Cohort, which includes adults over 40 years of age, was assessed from 2002 to 2015. A total of 5844 PD patients were matched by age, sex, income, and region of residence with 23,376 control participants at a ratio of 1:4. The analyzed covariates included age, sex, blood pressure, fasting blood glucose, obesity, smoking status, and alcohol consumption. A multiple logistic regression analysis was conducted for case-control analyses. (3) Results: The adjusted odds ratio (OR) for the risk of PD associated with anemia was 1.09 after adjusting for potential confounders (95% confidence interval (CI) 1.01-1.18, p = 0.030). Among men younger than 70 years, the adjusted OR of PD was 1.34 (95% CI 1.13-1.60, p = 0.001). (4) Conclusions: Our findings suggest that anemia may increase the risk of PD, particularly in men younger than 70 years. Further research is required to elucidate the causal relationship between these two diseases.

Mortality and cause of death in physical activity and insufficient physical activity participants: a longitudinal follow-up study using a national health screening cohort

Background

Few studies have examined the association between physical activity (PA) and various causes of mortality in Korea. The aim of our study was to evaluate mortality and causes of death between PA and insufficient PA using Korean national cohort data.

Methods

The health screening cohort data from the Korean National Health Insurance Service-National Sample Cohort from 2009 to 2015 were used. ‘PA’ was determined if participants walked or performed moderate-intensity activity ≥5 d/week for ≥30 min, or vigorous-intensity activity ≥3 d/week for ≥20 min. Other participants were classified as ‘insufficient PA’. The PA and insufficient PA groups were matched by age, sex, income, and region of residence in a 1:1 ratio. Causes of death were classified into 13 categories. Crude and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for all mortality rates were analyzed using a stratified Cox proportional hazard model. Age, sex, income, and region of residence were stratified. Subgroup analyses were performed according to age, sex, and obesity status. The odds ratio according to the causes of death was calculated by the chi-square test.

Results

The adjusted HR for mortality in the PA group was 0.85 (95% CI = 0.82–0.88). In subgroup analyses according to age, sex, and obesity status, results were consistent with the main findings in < 60-year-old females, ≥ 60-year-old males and females, and in all subgroups by obesity. The death rate by neoplasm, mental diseases, neurologic disease, circulatory disease, respiratory disease, digestive disease, abnormal finding, and trauma were lower in the PA than the insufficient PA group.

Conclusions

These results suggest that PA is inversely associated with mortality caused specifically by diseases reflected by mental, respiratory, cancer, and cardiovascular conditions. Additionally, PA is inversely associated with mortality compared to insufficient PA in all obesity status.