Possible Incidental Parkinson's Disease following Asthma: A Nested Case-Control Study in Korea

Reduced Risk of Benign Paroxysmal Positional Vertigo in Patients with Parkinson's Disease: A Nationwide Korean Cohort Study

Background/Objectives: Parkinson's disease (PD) and benign paroxysmal positional vertigo (BPPV) are both prevalent in the geriatric population. While dizziness is a common non-motor symptom in PD, the relationship between PD and incident BPPV remains unclear. Limited data suggest potential shared mechanisms, including mitochondrial dysfunction and oxidative stress, but large-scale epidemiological evidence is lacking. This investigation focused on assessing the incidence of BPPV in patients with PD compared to matched controls using a nationwide cohort. Methods: Data from the Korean National Health Insurance Service-Health Screening Cohort were used to perform a retrospective cohort analysis. We identified 8232 newly diagnosed PD patients and matched them 1:4 with 32,928 controls based on age, sex, income, and residential region. Stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident BPPV. Subgroup and Kaplan-Meier analyses were also performed. Results: Over 220,151 person-years of follow-up revealed a lower incidence of BPPV in the PD group relative to the control group (4.98 vs. 5.95 per 1000 person-years); the corresponding adjusted HR was 0.77 (95% CI: 0.66-0.90; p = 0.001), indicating a 23% reduced risk. The inverse association remained consistent across most subgroups, including older adults and rural residents. Kaplan-Meier analysis further illustrated a significant decline in the cumulative incidence of BPPV in PD patients (p = 0.007). Conclusions: PD may contribute to a lower incidence of BPPV, which could be explained by reduced mobility, altered vestibular function, or diagnostic challenges. Clinicians should consider BPPV in PD patients presenting with dizziness.

Use of β-adrenoreceptor drugs and Parkinson's disease incidence in women from the French E3N cohort study

BackgroundExperimental and observational studies suggest that β-adrenoreceptor drugs (β2-agonists/β-antagonists) are associated with Parkinson's disease (PD) risk. Previous epidemiological studies may be hampered by reverse causation/confounding.ObjectiveWe examined the association of β-adrenoreceptor drugs with PD incidence, while addressing reverse causation and confounding in the E3N cohort study (2004-2018) using a new-user design.MethodsIncident β2-agonists/β-antagonists users were identified through drug claims databases. Incident PD was ascertained using multiple sources and validated by experts. Drugs-PD associations were assessed using time-varying Cox proportional hazards models adjusted for multiple confounders. Main analyses used a 5y-exposure lag to address reverse causation; sensitivity analyses used a 2y-lag or no lag. We set up a nested case-control study to compare trajectories of β2-agonists/β-antagonists prescriptions before diagnosis using logistic mixed models.ResultsAnalyses for β2-agonists were based on 81,890 women; 15,169 started using β2-agonists and 579 developed PD. PD incidence was 36% lower (hazard ratio = 0.64, 95% confidence interval = 0.41-0.98; p-trend = 0.04 for the number of claims) in users of long-acting/ultra-long-acting β2-agonists (LABAs/ultra-LABAs) compared to never users. There was no significant association for β2-agonists overall and short-acting β2-agonists. Analyses for β-antagonists were based on 75,896 women; 13,081 started using β-antagonists and 552 developed PD. PD incidence was similar in ever and never users in analyses with a 5y-lag but was higher in ever than never users in analyses with 2y-lag or no lag.ConclusionsIncident use of LABAs/ultra-LABAs is associated with lower PD incidence in women. Conversely, the association between β-antagonists and PD in women is likely due to reverse causation.

House dust mite-induced asthma exacerbates Alzheimer's disease changes in the brain of the AppNL-G-F mouse model of disease

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ) plaques, neuroinflammation, and neuronal death. Besides aging, various comorbidities increase the risk of AD, including obesity, diabetes, and allergic asthma. Epidemiological studies have reported a 2.17-fold higher risk of dementia in asthmatic patients. However, the molecular mechanism(s) underlying this asthma-associated AD exacerbation is unknown. This study was designed to explore house dust mite (HDM)-induced asthma effects on AD-related brain changes using the AppNL-G-F transgenic mouse model of disease. Male and female 8-9 months old C57BL/6J wild type and AppNL-G-F mice were exposed to no treatment, saline sham, or HDM extract every alternate day for 16 weeks for comparison across genotypes and treatment. Mice were euthanized at the end of the experiment, and broncho-alveolar lavage fluid (BALF), blood, lungs, and brains were collected. BALF was used to quantify immune cell phenotype, cytokine levels, total protein content, lactate dehydrogenase (LDH) activity, and total IgE. Lungs were sectioned and stained with hematoxylin and eosin, Alcian blue, and Masson's trichrome. Serum levels of cytokines and soluble Aβ1-40/42 were quantified. Brains were sectioned and immunostained for Aβ, GFAP, CD68, and collagen IV. Finally, frozen hippocampi and temporal cortices were used to perform Aβ ELISAs and cytokine arrays, respectively. HDM exposure led to increased levels of inflammatory cells, cytokines, total protein content, LDH activity, and total IgE in the BALF, as well as increased pulmonary mucus and collagen staining in both sexes and genotypes. Levels of serum cytokines increased in all HDM-exposed groups. Serum from the AppNL-G-F HDM-induced asthma group also had significantly increased soluble Aβ1-42 levels in both sexes. In agreement with this peripheral change, hippocampi from asthma-induced male and female AppNL-G-F mice demonstrated elevated Aβ plaque load and increased soluble Aβ 1-40/42 and insoluble Aβ 1-40 levels. HDM exposure also increased astrogliosis and microgliosis in both sexes of AppNL-G-F mice, as indicated by GFAP and CD68 immunoreactivity, respectively. Additionally, HDM exposure elevated cortical levels of several cytokines in both sexes and genotypes. Finally, HDM-exposed groups also showed a disturbed blood-brain-barrier (BBB) integrity in the hippocampus of AppNL-G-F mice, as indicated by decreased collagen IV immunoreactivity. HDM exposure was responsible for an asthma-like condition in the lungs that exacerbated Aβ pathology, astrogliosis, microgliosis, and cytokine changes in the brains of male and female AppNL-G-F mice that correlated with reduced BBB integrity. Defining mechanisms of asthma effects on the brain may identify novel therapeutic targets for asthma and AD.

Investigating the Connection between Chronic Periodontitis and Parkinson's Disease: Findings from a Korean National Cohort Study

Recent research suggests a potential relevance between chronic periodontitis (CP) and Parkinson's disease (PD), raising concerns about comorbid PD among elderly CP patients. However, the epidemiologic basis for this association remains unclear. Employing a nested case-control design, this study explored the association between CP and subsequent PD occurrences in Korean adults, leveraging a validated national population-based dataset covering the period from 2002 to 2019. It included 8794 PD patients and 35,176 matched control individuals, established through propensity score matching for age, sex, residential area, and income. Baseline characteristics were compared using standardized differences, and logistic regression was employed to assess the impact of CP histories on PD likelihood while controlling for covariates. We performed a thorough examination of CP events within both 1-year and 2-year intervals preceding the index date, incorporating subgroup analyses. Our analysis revealed no statistically significant association between CP history and PD development overall. However, subgroup analysis revealed a slightly increased likelihood of PD development among CP individuals with a high disease burden (Charlson Comorbidity Index score ≥ 2). In conclusion, although our study did not find a significant overall association between CP history and PD development, the elevated likelihood of PD in subgroups with high disease burden may suggest that comorbidities influence PD probability among certain CP patients. Considering comorbid conditions in PD screening for some individuals with CP may be also important.

Chronic Periodontitis and the Potential Likelihood of Gastric Cancer: A Nested Case-Control Study in the Korean Population Utilizing a National Health Sample Cohort

There is limited information regarding the potential association between chronic periodontitis (CP) and gastric cancer, especially in the Korean population. This study aimed to explore this relationship. This nested case-control study analyzed data from 10,174 patients with gastric cancer and 40,696 controls from the Korean National Health Insurance Service-National Sample Cohort using propensity score matching. Standardized differences were used to compare baseline characteristics between study groups. Logistic regression analyses adjusted for confounders were conducted to assess the association between history of CP and gastric cancer occurrence. CP histories and comprehensive subgroup analyses in the 1- and 2-year periods preceding the index date were evaluated. Individuals with a history of CP within the 1-year and 2-year periods showed an increased likelihood of developing gastric cancer. Subgroup analyses consistently supported these findings in male participants aged <65 years and individuals with various income levels or living in residential areas. However, no significant associations were observed among participants aged ≥65 years. In conclusion, CP may be a potential risk factor for gastric cancer development in the Korean population. Regular screening for gastric cancer may be necessary for high-risk individuals, specifically men aged <65 years with a history of CP.