A Bayesian Approach to Identifying New Risk Factors for Dementia: A Nationwide Population-Based Study

Inequalities in the Prevention and Treatment of Alzheimer Disease

Incidence of Alzheimer disease (AD) is going to rise in the next years and to become a health and social emergency. The prevention and the therapeutic management of AD still present unmet needs worldwide. The recent approval of monoclonal antibodies against amyloid β (anti-Aβ mAbs) for AD has increased the level of uncertainty regarding on how such drugs should be administered, to whom, and for how long. Concerns about cost-effectiveness ratios of anti-Aβ mAbs and the need for actual strategies of risk prevention have further dug barriers of inequalities between the national health care systems. Planning research to address questions on the real feasibility of the correct therapeutic management, improving international cooperation on surveillance of risk factors, implementing pathways for timely diagnosis, and effective medical and social support for patients with AD worldwide would be extremely valuable to fight against this upcoming pandemic.

The association between cataract and incidence of cognitive impairment in older adults: A systematic review and meta-analysis

BACKGROUND

Cataract has been shown to be associated with an increased risk of cognitive impairment. However, the results of previous studies have been inconsistent. This systematic review and meta-analysis aimed to investigate the association between cataract and the incidence of cognitive impairment in older adults.

METHODS

A comprehensive search of electronic databases from inception to January 2023 was performed to identify relevant studies. Data were extracted from eligible studies and a meta-analysis was performed to calculate the pooled hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

We included 13 studies with 25 study arms involving a total of 798,694 participants. Compared with participants without cataract, those with cataract had a higher risk of developing all-cause dementia (pooled HR: 1.22; 95% CI: 1.08-1.38; I²=86%; 9 studies), Alzheimer's disease dementia (pooled HR: 1.18; 95% CI: 1.07-1.30; I²=0%; 9 studies), vascular dementia (pooled HR: 1.21; 95% CI: 1.02-1.43; I²=77%;3 studies) and mild cognitive impairment (pooled HR: 1.30; 95% CI: 1.13-1.50; I²=0%;2 studies). There was no significant association between cataract and mixed dementia (pooled HR: 1.03; 95% CI: 0.52-2.04; I²=78%;2 studies). We assessed the risk of bias of the included studies using the Newcastle-Ottawa Scale and found that most of them had a low or moderate risk of bias. The number of studies in each meta-analysis ranged from two to nine, with more studies available for all-cause dementia and Alzheimer's disease dementia than for vascular dementia and mixed dementia.

CONCLUSIONS

The findings suggest that cataract may be associated with cognitive impairment in older adults. However, the causal relationship between cataract and cognition remains unclear and requires further investigation.

Association between atrial fibrillation and risk of end-stage renal disease among adults with diabetes mellitus

Diabetes mellitus (DM) is an important risk factor in patients with end-stage renal disease (ESRD). DM is associated with the development of cardiovascular diseases, such as atrial fibrillation (AF), due to poor glycemic control. However, few studies have focused on the risk of developing ESRD among DM patients with and without AF. This study evaluated ESRD risk among DM patients with and without AF in Taiwan. Data were retrieved from one million patients randomly sampled from Taiwan’s National Health Insurance Research Database, including 6,105 DM patients with AF propensity score–matched with 6,105 DM patients without AF. Both groups were followed until death, any dialysis treatment, or December 31, 2013, whichever occurred first. AF was diagnosed by a qualified physician according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), using the diagnostic code 427.31. Patients aged <20 years or diagnosed with ESRD before the index date were excluded. A Cox proportional hazard regression model was used to calculate the relative ESRD risk. Among DM patients, those with AF have more comorbidities than those without AF. We also found a 1.18-fold (95% confidence interval [CI]: 1.01–1.46) increase in ESRD risk among patients with AF compared with those without AF. In addition, DM patients with hypertension, chronic kidney disease (CKD), or higher Charlson Comorbidity Index scores also have significantly increased ESRD risks than those without these complications. A 1.39-fold (95% CI: 1.04–1.86) increase in risk was observed for patients with AF among the non-CKD group. Our findings suggest that patients with DM should be closely monitored for irregular or rapid heart rates.

Sex-Related Differences in the Associations Between Montreal Cognitive Assessment Scores and Pure-Tone Measures of Hearing

PURPOSE

Hearing loss (HL) is associated with cognitive performance in older adults, including performance on the Montreal Cognitive Assessment (MoCA), a brief cognitive screening test. Yet, despite well-established sex-related differences in both hearing and cognition, very few studies have tested whether there are sex-related differences in auditory-cognitive associations.

METHOD

In the current cross-sectional retrospective analysis, we examined sex-related differences in hearing and cognition in 193 healthy older adults (M = 69 years, 60% women). Hearing was measured using audiometry (pure-tone average [PTA] of thresholds at 500, 1000, 2000, and 4000 Hz in the worse ear). Cognition was assessed using the MoCA. Additionally, we calculated MoCA scores with hearing-dependent subtests excluded from scoring (MoCA-Modified).

RESULTS

Men and women did not differ in age, education, or history of depression. Women had better hearing than men. Women with normal hearing were more likely to pass the MoCA compared with their counterparts with HL. In contrast, the likelihood of passing the MoCA did not depend on hearing status in men. Linear regression analysis showed an interaction between sex and PTA in the worse ear. PTAs were significantly correlated with both MoCA and MoCA-Modified scores in women, whereas this was not observed in the men.

CONCLUSIONS

This study is one of the first to demonstrate significant sex-related differences in auditory-cognitive associations even when hearing-related cognitive test items are omitted. Potential mechanisms underlying these female-specific effects are discussed.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19233297.

The Association Between Parkinson's Disease and Attention-Deficit Hyperactivity Disorder

While Parkinson’s disease (PD) and attention-deficit hyperactivity disorder (ADHD) are two distinct conditions, it has been hypothesized that they share several overlapping anatomical and neurochemical changes. In order to investigate that hypothesis, this study used claims data from Taiwan’s Longitudinal Health Insurance Database 2000 to provide the significant nationwide population-based evidence of an increased risk of PD among ADHD patients, and the connection between the two conditions was not the result of other comorbidities. Moreover, this study showed that the patients with PD were 2.8 times more likely to have a prior ADHD diagnosis compared with those without a prior history of ADHD. Furthermore, an animal model of ADHD was generated by neonatally injecting rats with 6-hydroxydopamine (6-OHDA). These rats were subjected to behavior tests and the 99mTc-TRODAT-1 brain imaging at the juvenile stage. Compared to control group rats, the 6-OHDA rats showed a significantly reduced specific uptake ratio in the striatum, indicating an underlying PD-linked pathology in the brains of these ADHD phenotype-expressing rats. Overall, these results support that ADHD shares a number of anatomical and neurochemical changes with PD. As such, improved knowledge of the neurochemical mechanisms underlying ADHD could result in improved treatments for various debilitating neurological disorders, including PD.

Higher Dementia Incidence in Older Adults with Poor Visual Acuity

Background

Longitudinal evidence of poor visual acuity associating with higher risk of incident dementia is mixed. This study aimed to examine if poor visual acuity was associated with higher dementia incidence in a large community cohort of older adults, independent of the possible biases relating to misclassification error, reverse causality, and confounding effects due to health problems and behaviors.

Methods

A total of 15,576 community-living older adults without dementia at baseline were followed for 6 years to the outcome of incident dementia, which was diagnosed according to the ICD-10 or a Clinical Dementia Rating of 1 to 3. Visual acuity was assessed using the Snellen’s chart at baseline and follow-up. Important variables including demographics (age, sex, education, and socioeconomic status), physical and psychiatric comorbidities (cardiovascular risks, ophthalmological conditions, hearing impairment, poor mobility, and depression), and lifestyle behaviors (smoking, diet, physical, intellectual, and social activities) were also assessed.

Results

Over 68,904 person-years of follow-up, 1,349 participants developed dementia. Poorer visual acuity at baseline was associated with higher dementia incidence in 6 years, even after adjusting for demographics, health problems, and lifestyle behaviors, and excluding those who developed dementia within 3 years after baseline. Compared with normal vision, the hazard ratio of dementia was 1.19 (p = .31), 2.09 (p < .001), and 8.66 (p < .001) for mild, moderate, and severe visual impairment, respectively.

Conclusions

Moderate-to-severe visual impairment could be a potential predictor and possibly a risk factor for dementia. From a clinical perspective, older adults with poor visual acuity might warrant further risk assessment for dementia.

Hearing Screening for Residents in Long-Term Care Homes Who Live with Dementia: A Scoping Review

BACKGROUND

Hearing loss is highly prevalent in older adults, particularly among those living with dementia and residing in long-term care homes (LTCHs). Sensory declines can have deleterious effects on functioning and contribute to frailty, but the hearing needs of residents are often unrecognized or unaddressed.

OBJECTIVE

To identify valid and reliable screening measures that are effective for the identification of hearing loss and are suitable for use by nursing staff providing care to residents with dementia in LTCHs.

METHODS

Electronic databases (Embase, Medline, PsycINFO, CENTRAL, and CINAHL) were searched using comprehensive search strategies, and a stepwise approach based on Arksey & O'Malley's scoping review and appraisal process was followed.

RESULTS

There were 193 scientific papers included in the review. Pure-tone audiometry was the most frequently reported measure to test hearing in older adults living with dementia. However, measures including self- or other-reports and questionnaires, review of medical records, otoscopy, and the whisper test were found to be most suitable for use by nurses working with older adults living with dementia in LTCHs.

CONCLUSION

Although frequently used, the suitability of pure-tone audiometry for use by nursing staff in LTCHs is limited, as standardized audiometry presents challenges for many residents, and specific training is needed to successfully adapt test administration procedures and interpret results. The whisper test was considered to be more suitable for use by staff in LTCH; however, it yields a limited characterization of hearing loss. There remains an urgent need to develop new approaches to screen hearing in LTCHs.

Assessment and Modeling of the Influence of Age, Gender, and Family History of Hearing Problems on the Probability of Suffering Hearing Loss in the Working Population

Hearing loss affects hundreds of millions of people all over the world, leading to several types of disabilities, ranging from purely physical to psychological and/or social aspects. A proper analysis to ascertain the main risk factors is essential in order to diagnose early and treat adequately. An exploratory analysis based on a heterogeneous sample of 1418 workers is presented in order to identify the main trigger factors for hearing loss. On the one hand, we recorded several medical and environmental parameters, and on the other, we created a model based on Bayesian networks in order to be able to infer the probability of hearing loss considering different scenarios. This paper focuses on three parameters: gender, age, and a family history of hearing problems. The results obtained allow us to infer or predict the best or worst auditory level for an individual under several different scenarios. The least relevant factor is the existence of a family history of deafness, followed by the gender factor, which slopes considerably toward better hearing for females, and most prominent of all, the age factor, given the large differences identified between the various age groups when the gender and family history of deafness variables remain constant.

Exploring prior diseases associated with incident late-onset Alzheimer's disease dementia

Studies have identified prior conditions associated with late-onset Alzheimer's disease dementia (LOAD), but all prior diseases have rarely been screened simultaneously in the literature. Our objective in the present study was to identify prior conditions associated with LOAD and construct pathways for them. We conducted a population-based matched case-control study based on data collected in the National Health Insurance Research database of Taiwan and the Catastrophic Illness Certificate database for the years 1997-2013. Prior diseases definitions were based on the first three digits of the codes listed in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Inclusion criteria required that each ICD-code existed for at least 1 year and incurred at least 2 outpatient visits or inpatient diagnosis. The case group comprised 4,600 patients newly diagnosed with LOAD in 2007-2013. The LOAD patients were matched by sex and age to obtain 4,600 controls. Using stepwise multivariate logistic regression analysis, diseases were screened for 1, 2 …, 9 years prior to the first diagnosis of LOAD. Path analysis was used to construct pathways between prior diseases and LOAD. Our results revealed that the following conditions were positively associated with the incidence of LOAD: anxiety (ICD-code 300), functional digestive disorder (ICD code 564), psychopathology-specific symptoms (ICD-code 307), disorders of the vestibular system (ICD-code 386), concussion (ICD-code 850), disorders of the urethra and urinary tract (ICD-code 599), disorders of refraction and accommodation (ICD-code 367), and hearing loss (ICD-code 389). A number of the prior diseases have previously been described in the literature in a manner identical to that in the present study. Our study supports the assertion that mental, hearing, vestibular system, and functional digestive disorders may play an important role in the pathogenesis of LOAD.

The association between Parkinson's disease and temporomandibular disorder

The prevalence of temporomandibular disorder (TMD) among elderly people with Parkinson’s disease (PD) is relatively high, but a population-based study of the relationship between PD and TMD is still lacking. This study, therefore, sought to investigate the association between TMD and PD by using data for one million randomly sampled beneficiaries of Taiwan’s National Health Insurance program, including 6,185 PD patients who were matched through propensity score matching with 18,555 non-PD patients. Both the PD and non-PD cohorts were followed until death, any diagnosis of TMD, or December 31, 2013, whichever occurred first. Each diagnosis of TMD was made by a qualified physician according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), using the diagnosis codes 524.60, 524.62, 524.63, and 524.69 while excluding tooth abscess, wisdom tooth eruption, herpes zoster and postherpetic neuralgia, mastoiditis, otitis externa, otitis media, parotitis, sialadenitis, and trigeminal neuralgia. We used Cox proportional hazard regression models to calculate the relative risk of TMD and found a 2.11-fold (95% CI: 1.35–3.30) increased risk of TMD overall in the PD group compared with the non-PD group. Stratified by follow-up period, there was a 4.25-fold (95% CI: 1.51–11.93) increased risk in the PD group in the first year after the initial PD diagnosis and a 3.88-fold (95% CI: 1.33–11.28) increased risk in the second year. Over the long-term (>5 years), PD was significantly associated with an increased risk of TMD. These findings suggest that it is important to closely monitor the temporomandibular joint health of PD patients.

Reversible Dementias

As the worldwide prevalence of dementia increases, there is a greater and more urgent need for all health care providers to understand how to evaluate and manage cognitive impairment. Many people presenting with a dementing illness have one or more reversible underlying conditions that worsen prognosis and, if treated, can improve cognitive function. This article reviews the major potentially reversible dementias, including the basic workup and management of each condition.

Quantitative comorbidity risk assessment of dementia in Taiwan: A population-based cohort study

Dementia is one of the most burdensome illnesses in elderly populations worldwide. However, the literature about multiple risk factors for dementia is scant.To develop a simple, rapid, and appropriate predictive tool for the clinical quantitative assessment of multiple risk factors for dementia.A population-based cohort study.Based on the Taiwan National Health Insurance Research Database, participants first diagnosed with dementia from 2000 to 2009 and aged ≥65 years in 2000 were included.A logistic regression model with Bayesian supervised learning inference was implemented to evaluate the quantitative effects of 1- to 6-comorbidity risk factors for dementia in the elderly Taiwanese population: depression, vascular disease, severe head injury, hearing loss, diabetes mellitus (DM), and senile cataract, identified from a nationwide longitudinal population-based database.This study enrolled 4749 (9.5%) patients first diagnosed as having dementia. Aged, female, urban residence, and low income were found as independent sociodemographic risk factors for dementia. Among all odds ratios (ORs) of 2-comorbidity risk factors for dementia, comorbid depression and vascular disease had the highest adjusted OR of 6.726. The 5-comorbidity risk factors, namely depression, vascular disease, severe head injury, hearing loss, and DM, exhibited the highest OR of 8.767. Overall, the quantitative effects of 2 to 6 comorbidities and age difference on dementia gradually increased; hence, their ORs were less than additive. These results indicate that depression is a key comorbidity risk factor for dementia.The present findings suggest that physicians should pay more attention to the role of depression in dementia development. Depression is a key cormorbidity risk factor for dementia. It is the urgency of evaluating the nature of the link between depression and dementia; and further testing what extent controlling depression could effectively lead to the prevention of dementia.

Hearing loss as a risk factor for dementia: A systematic review

OBJECTIVES

To review evidence of hearing loss as a risk factor for dementia. Data Sources: PubMed Review methods: A systematic review was conducted using the PubMed database using the search terms (hearing loss OR presbycusis) AND (dementia OR cognitive decline). Initially, 488 articles were obtained. Only those studies evaluating an association between hearing loss and incident dementia or cognitive decline were included in the analysis. This resulted in 17 articles which were thoroughly evaluated with consideration for study design, method for determining hearing loss and cognitive status, relevant covariates and confounding factors, and key findings.

RESULTS

All of the 17 articles meeting inclusion criteria indicate that hearing loss is associated with dementia or cognitive decline. The methods used among the studies for ascertaining hearing loss and dementia were notably varied. For hearing loss, peripheral auditory function was tested far more than central auditory function. For peripheral audition, pure tone audiometry was the most commonly reported method for defining hearing loss. Only a few studies measured central auditory function by using the Synthetic Sentence Identification with Ipsilateral Competing Message test (SSI-ICM) and the Staggered Spondaic Word Test (SSW). Dementia was most often defined using the Mini Mental State Exam (MMSE). However, many studies used extensive batteries of tests to define cognitive status, often including a neuropsychologist. Confounding variables such as cardiovascular risk factors were measured in 17 studies and family history of dementia was only evaluated in 1 study. Overall, the methods used by studies to ascertain hearing loss, cognitive status and other variables are valid, making their evaluation appear reliable.

CONCLUSION

While each of the studies included in this study utilized slightly different methods for evaluating participants, each of them demonstrated that hearing loss is associated with higher incidence of dementia in older adults.

LEVEL OF EVIDENCE

Level V, systematic review.

Expression of S100β protein in patients with vascular dementia after basal ganglia hemorrhage and its clinical significance

We investigated the expression levels and clinical significance of S100β protein in patients with vascular dementia (VD) after basal ganglia hemorrhage. From June 2014 to December 2015, in 138 patients with basal ganglia hemorrhage, we carried out the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) in patients on the day before the operation, the day after the operation and 9 days after the operation. Thirty-two patients (blood vessel group) had cognitive dysfunction and 106 patients (control group) had VD. One hundred thirty-eight cases of healthy adult volunteers were treated in Henan Provincial People's Hospital and were selected in the same period as healthy controls. The expression levels of serum S100β in the three groups were tested through the ELISA method and the statistical analysis was carried out. In VD patients, the serum S100β levels of patients were significantly higher than VD and healthy control groups; differences were statistically significant (P<0.05). However, there was no significant difference between those without VD after operation and the healthy control group (P>0.05). The correlation analysis was carried out with serum S100β as an independent variable and mean arterial pressure, BMI, MMSE and MoCA scores as dependent variables. Our results suggest that S100β expression levels were negatively correlated to the MMSE score (rs=-4.19) and the difference was statistically significant (P<0.05). The length of hospital stay of patients with basal ganglia hemorrhage associated with VD was significantly extended, with a mean of 23.4±2.8 days. The expression levels of S100β protein in the serum of patients with VD after basal ganglia hemorrhage was significantly increased and negatively correlated to the cognitive function of patients. Therefore, it can be used as a differential diagnosis indicator of VD after the basal ganglia hemorrhage and treatment target point of the VD.

Risk of dementia from proton pump inhibitor use in Asian population: A nationwide cohort study in Taiwan

Introduction

Concerns have been raised regarding the potential association between proton pump inhibitor (PPI) use and dementia.

Objective

This study aimed to examine this association in an Asian population.

Methods

Patients initiating PPI therapy between January 1, 2000 and December 31, 2003 without a prior history of dementia were identified from Taiwan’s National Health Insurance Research Database. The outcome of interest was all-cause dementia. Cox regression models were applied to estimate the hazard ratio (HR) of dementia. The cumulative PPI dosage stratified by quartiles of defined daily doses and adjusted for baseline disease risk score served as the primary variables compared against no PPI use.

Results

We analyzed the data of 15726 participants aged 40 years or older and free of dementia at baseline. PPI users (n = 7863; average follow-up 8.44 years) had a significantly increased risk of dementia over non—PPI users (n = 7863; average follow-up 9.55 years) (adjusted HR [aHR] 1.22; 95% confidence interval: 1.05–1.42). A significant association was observed between cumulative PPI use and risk of dementia (P for trend = .013). Subgroup analysis showed excess frequency of dementia in PPI users diagnosed with depression (aHR 2.73 [1.91–3.89]), hyperlipidemia (aHR 1.81 [1.38–2.38]), ischemic heart disease (aHR 1.55 [1.12–2.14]), and hypertension (aHR 1.54 [1.21–1.95]).

Conclusions

An increased risk for dementia was identified among the Asian PPI users. Cumulative PPI use was significantly associated with dementia. Further investigation into the possible biological mechanisms underlying the relationship between dementia and PPI use is warranted.