Bilingualism effect for delaying dementia onset: a Bayesian meta-analysis

Dementia brings a heavy burden on older adults, their family and the society at large. Accurate prediction of dementia prevlance is important for preventive strategy for fast- ageing China. The purpose of this study is to predict dementia prevalence in China by 2050, taking into account variations in dementia incidence rates and mortality rates in future. Based on two nationally representative Chinese ageing cohorts (i.e. CLHLS, CHARLS), a ten-state Markov model (IMPACT-CAM), including prevalence, transition probability and mortality rate of dementia and its associated cardiovaiscualr diseases and disability, was constructed to predict dementia prevalence in people aged above 60 years by 2050, with different assumptions on the furture trends of dementia incidence and mortality rates. IMPACT-CAM projected there were approximately 57.9 million (95% uncententiy interval 56.3-59.6 m) people with dementia by 2050, assuming constant incidence rate of dementia and declining mortality rates over coming years. In comparison with this assumption, if the incidence rate of dementia decreasing by 1.0% annually coupled with declining mortality rates, the projected number of dementia cases would be 9.8 million less; if dementia incidence and mortality rates both remained constant since 2022, the projection would be 18.5 million less. The estimated dementia prevlance for people aged 60 years in 2050 were 12.0%, 9.9% and 9.5%, respectively. Alongside the irreversible population ageing trend, the number of people with dementia in China is likely to increase rapidly in the near furture. Nevertheless, effective preventing measures of dementia would restrain the surge substantially.

Introduction: Parkinson's disease (PD) manifests with dominant motor symptoms and a wide range of non-motor symptoms (NMS). Dementia is one of the most disabling and exhausting NMS throughout the clinical course. We conducted a population-based, age-stratified, retrospective cohort study to investigate the incidence rate and risk of dementia of patients with newly diagnosed PD, and linked to the clinicopathological PD subtypes.Methods: Patients with newly diagnosed PD (PD group, n = 760) and control subjects (non-PD group, n = 3,034) were selected from the Taiwan's National Health Insurance Research Database from January 2001 to December 2005. The dementia incidence rate and dementia-free survival rate were calculated.Results: The overall dementia incidence rate was 17.5 and 5.7 per 1,000 person-years in PD and non-PD groups, respectively. The PD group had a significantly higher overall risk of dementia than controls (p < 0.001). The younger PD patients had a lower dementia incidence rate than the older PD patients, but a higher dementia risk compared to the same age of controls (<60 years, adjusted HR 6.55, 95% CI 1.56–27.48, p = 0.010). The dementia-free survival rate was significantly lower in the PD group compared to the non-PD group during follow-up (p < 0.001).Conclusion: In our study, the older age of onset in PD patients resulted in a higher incidence rate of dementia. In the young age of PD patients, the incidence rate of dementia was lower than the older PD patients, but the dementia risk was higher than controls of the same age. These findings possibly implied that there were different pathogenesis and pathologies causing dementia in younger and older PD patients.

Introduction: Parkinson’s disease (PD) manifests with dominant motor symptoms and a wide range of non-motor symptoms (NMS). Dementia is one of the most disabling and exhausting NMS throughout the clinical course. We conducted a population-based, age-stratified, retrospective cohort study to investigate the incidence rate and risk of dementia of patients with newly diagnosed PD, and linked to the clinicopathological PD subtypes. Methods: Patients with newly diagnosed PD (PD group, n=760) and control subjects (non-PD group, n=3034) were selected from the Taiwan’s National Health Insurance Research Database from January 2001 to December 2005. The dementia incidence rate and dementia-free survival rate were calculated. Results: The overall dementia incidence rate was 17.5 and 5.7 per 1000 person-years in PD and non-PD groups, respectively. The PD group had a significantly higher overall risk of dementia than controls (p<0.001). The younger PD patients had a lower dementia incidence rate than the older PD patients, but a higher dementia risk compared to the same age of controls (<60 years, adjusted HR 6.55, 95% CI 1.56–27.48, p=0.010). The dementia-free survival rate was significantly lower in the PD group compared to the non-PD group during follow-up (p<0.001). Conclusion: The older age of onset in PD patients resulted in a higher incidence rate of dementia. In the young age of PD patients, the incidence rate of dementia was lower than the older PD patients, but the dementia risk was higher than controls of the same age. These findings reflected that there were different pathogenesis and pathologies causing dementia in early-onset and late-onset PD patients.

Our purpose was to determine the association of cataract surgery with subsequent development of dementia in older adults with newly diagnosed cataract. By using data from Taiwan National Health Insurance Research Database (NHIRD), a population-based cohort study including 491226 subjects aged 70 or older with first-time diagnosis of cataract coded from 2000 to 2009 was conducted. After matching cataract patients receiving cataract surgery with cataract patients without receiving cataract surgery for age, sex, index date, Charlson Comorbidity Index score, interval between first coding of cataract diagnosis and index date, hypertension and diabetes mellitus, 113123 patients in each cohort were enrolled. The main outcome measure was newly diagnosed dementia coded by neurologists or psychiatrists more than 365days after cataract surgery. Incidence rate and hazard ratio of dementia were compared between the cataract surgery and cataract diagnosis cohorts. The incidence rate of dementia was 22.40 per 1000 person-years in the cataract surgery cohort and 28.87 per 1000 person-years in the cataract diagnosis cohort. The rate of dementia was significantly lower in the cataract surgery group (hazard ratio 0.77, 95% confidence interval 0.75-0.79, P<0.001). Female gender (P<0.001) and a shorter interval between the date of first coding of a cataract diagnosis and the date of cataract surgery (P=0.009) were significantly associated with a lower incidence rate of dementia. In an NHIRD cohort of Taiwanese aged 70years and older with a diagnosis of cataract, patients undergoing cataract surgery were associated with a reduced risk of subsequent dementia compared with those without cataract surgery.

To quantify the epidemiology of bladder cancer in Africa to guide a targeted public health response and support research initiatives. We systematically searched publicly available sources for population-based registry studies reporting the incidence of bladder cancer in Africa between January 1980 and June 2017. Crude incidence rates of bladder cancer were extracted. A Bayesian network meta-analysis model was used to estimate incidence rates. The search returned 1328 studies. A total of 22 studies carried out across 15 African countries met our pre-defined selection criteria. Heterogeneity across studies was high (I2 =98.9%, P<0.001). The pooled incidence of bladder cancer in Africa was 7.0 (95% credible interval 5.8-8.3) per 100000 population in men and 1.8 (95% credible interval 1.2-2.6) per 100000 in women. The incidence of bladder cancer was consistently higher in North Africa in both sexes. Among men, we estimated a pooled incidence of 10.1 (95% credible interval 7.9-11.9) per 100000 in North Africa and 5.0 (95% credible interval 3.8-6.6) per 100000 in sub-Saharan Africa. In women, the pooled incidence was 2.0 (95% credible interval 1.0-3.0) per 100000 and 1.5 (95% credible interval 0.9-2.0) per 100000 in North Africa and sub-Saharan Africa, respectively. Incidence rates increased significantly among men from 5.6 (95% credible interval 4.2-7.2) in the 1990s to 8.5 (95% credible interval 6.9-10.1) per 100000 in 2010. The present study suggests a growing incidence of bladder cancer in Africa in recent years, particularly among men and in North Africa. This study also highlights the lack of quality data sources and collection of essential clinical and epidemiological data in several African countries, and this hinders public health planning.

Data on the rate of dementia is essential for planning and developing appropriate services at the national level. We report the prevalence and incidence of dementia, based on electronic health records available for the whole population. This national dementia dataset was established as a part of the National Program to Address Alzheimer's and Other Types of Dementia. Data from medical health records for all persons aged 45+ in Israel, for 2016, were extracted from the databases of the four health maintenance organizations. Dementia cases were identified based on either recorded dementia diagnosis, through International Classification of Diseases (ICD-9 and ICD-10) or dispensation of anti-dementia drugs. The date of first diagnosis was determined by the earliest recording. A total of 65,951 persons with dementia, aged 45+, were identified from electronic health data. Based on both ICD codes and anti-dementia drugs, the prevalence rates of dementia among individuals aged 45+ and 65+ in 2016 were 2.5%and 6.4%, respectively, and the incidence rates were 0.49%and 1.3%, respectively. Based on ICD codes alone, the prevalence rates of dementia among individuals aged 45+ and 65+ in 2016 were 2.1%and 5.4%respectively, and the incidence rates were 0.36%and 0.96%respectively. The rates were higher among females compared to males and paradoxically lower in lower socioeconomic status compared to higher statuses. This data collection reflects the present access of dementia patients to medical care resources and provides the basis for service planning and future dementia policies.

The prevalence rate of Alzheimer's disease (AD) in people with Down's syndrome (DS) increases significantly with age. However, the nature of the early clinical presentation, course and incidence rates of dementia are uncertain. The aims of the present study were to investigate the characteristics of age-related clinical changes and incidence rates for dementia in a population-based sample of people with DS aged 30 years and older at the age of risk for dementia. A modified version of the Cambridge Examination for Mental Disorders of the Elderly informant interview was used to determine the extent and nature of changes in memory, personality, general mental functioning and daily living skill 18 months after a similar assessment At the time of the first assessment, the initial changes reported were predominately in behaviour and personality. At the second assessment, overall estimated incidence rates for frontal-like dementia were high (0.24), mainly in the younger groups, with incidence rates of AD, meeting both ICD-10 and DSM-IV criteria, of 0.04 predominately in the older groups. The present authors have hypothesized that the observed personality changes and the high estimated incidence rates of frontal-like dementia in the younger groups may indicate that functions served by the frontal lobes are the first to be compromised with the progressive development of Alzheimer-like neuropathology in people with DS.

Dementia is an age associated illness with a devastating impact on patients and their families. In the USA, the broader society impact of dementia continues to be overwhelming, due largely to the huge health care and economic burden associated with the disease. Although the projected numbers of those affected, the economic, healthcare, and caregiver costs continue to have a place in US public policy, it is only recently that these issues are beginning to take a center stage in other regions in the world with their aging populations. It has been estimated that 35.6 million people are living with dementia worldwide—a number that is projected to increase to 65.7 million by 2030 and 115.4 million by 2050. Approximately, 60% of the worlds' population lives in the Asian Pacific region—a home to many different ethnic groups. This issue of the International Journal of Alzheimer's Disease is dedicated to dementia in the Asian and Pacific region and discusses from an Asian-Pacific perspective common themes often noted in the literature from Europe and North America. Themes discussed in this special issue include (1) the prevalence and incidence rates of dementia in Asian countries, (2) the role of biological and genetic risk factors to the development of dementia, (3) characterization of dementia in culturally diverse populations, and (4) activities of daily living functioning and its relation to cognitive functioning. In this issue, two studies examined the prevalence, incidence, and mortality rates of dementia. H. H. Dodge et al. examined changes in dementia prevalence and the relative prevalence of AD compared to VaD over time using eight large Japanese prevalence studies. Unlike past studies on this topic, the authors thoroughly examined diagnostic criteria used in each study (through contacting original investigators of the most studies), changing age structures as well as regional variability as possible explanations of trends in overall prevalence and ratios of AD to VaD. The study suggests that, in contrast to the USA and some European countries, all-cause dementia prevalence is increasing in Japan. It was inconclusive whether the prevalence of AD as opposed to VaD has been increasing or not, because of variability in diagnostic criteria, regional variability, and gender difference in vascular disease prevalence. This study illustrates the complexity of evaluating prevalence rates of dementia and how knowledge of population trends in risk factors and diagnostic methods influences the interpretation of data. In addition, the authors offer useful suggestions for future epidemiological work on dementia prevalence and incidence in Japan which may be applied to other countries. In another article, the prevalence rates and mortality of dementia was examined in elderly persons living in Hong Kong. This study suggests that within 30 years the number of people in Hong Kong aged 60 and older will be more than triple; thus, the increase of prevalence of dementia cases in this region will prove to be substantial. The authors also discuss two other important issues related to care for those with dementia: (1) the impact of a declining “oldest old support ratio” and (2) the burden of dementia as measured by the Disability Adjusted Life Years (DALYs) approach. The authors postulate that by using these two metrics, in addition to data regarding the ongoing trends in the region, a successfully long-term care strategy for dementia of the aging population in Hong Kong can be achieved.

ObjectiveMatrix metalloproteinases (MMPs) may play a role in the pathophysiology of neurodegenerative disease and hernia formation. This retrospective cohort study was designed to assess whether there is an association between hernia and the risk of dementia.Materials and MethodsPatients (≥45 years) with hernias were identified between 2000 and 2008 from a longitudinal claims data of one million beneficiaries from Taiwan's National Health Insurance program. A control group of patients with comparable distributions of sex, age, socioeconomic status, urbanization, and medical comorbidities without hernia were chosen for matching in a ratio of 1:1. Patients previously diagnosed with dementia were excluded. Follow‐up ended on December 31, 2013. Incidence rate of dementia was compared between patients with hernias and those without. Cox proportional hazards models were used to estimate hazards relative to those of the control group.ResultsAfter matching, there were 4,784 hernia and 4,784 nonhernia patients. Hernia patients showed a higher incidence rate and hazard ratio of dementia than those in nonhernia group (8.82 vs. 7.19/1,000 person‐years; adjusted hazard ratio [aHR], 1.24; 95% CI, 1.07 to 1.45; p < .01). Advanced age (p < .0001), hypertension (p = .0139), head injury (p = .0003), and stroke (p = .041) were found to be risk factors for dementia, while patients with high socioeconomic status (p < .01) and history of coronary artery disease (p = .0292) were unlikely to develop dementia in our cohort study.ConclusionPatients with hernias were associated with a higher incidence of dementia than those without. Our finding should be validated in further prospective studies with larger samples.

This study aimed to investigate whether sarcopenia independently increases the risk of diabetes-induced dementia in elderly individuals diagnosed with type 2 diabetes mellitus. The study cohort consisted of a large sample of elderly individuals aged 60 years and above, who were diagnosed with type 2 diabetes mellitus between 2008 and 2018. To minimize potential bias and achieve covariate balance between the sarcopenia and non-sarcopenia groups, we employed propensity score matching. Various statistical analyses, including Cox regression models to assess dementia risk and associations, competing risk analysis to account for mortality and Poisson regression analysis for incidence rates, were used. Before propensity score matching, the study included 406 573 elderly type 2 diabetes mellitus patients, with 20 674 in the sarcopenia group. Following propensity score matching, the analysis included a total of 41 294 individuals, with 20 647 in the sarcopenia group and 20 647 in the non-sarcopenia group. Prior to propensity score matching, elderly type 2 diabetes mellitus patients with sarcopenia exhibited a significantly higher risk of dementia (adjusted hazard ratio: 1.12, 95% confidence interval: 1.07-1.17). After propensity score matching, the risk remained significant (adjusted hazard ratio: 1.14, 95% confidence interval: 1.07-1.21). Incidence rates of dementia were notably higher in the sarcopenia group both before and after propensity score matching, underscoring the importance of sarcopenia as an independent risk factor. Our study highlights sarcopenia as an independent risk factor for diabetes-induced dementia in elderly type 2 diabetes mellitus patients. Advanced age, female gender, lower income levels, rural residency, higher adapted diabetes complication severity index and Charlson Comorbidity Index scores and various comorbidities were associated with increased dementia risk. Notably, the use of statins was linked to a reduced risk of dementia. This research underscores the need to identify and address modifiable risk factors for dementia in elderly type 2 diabetes mellitus patients, offering valuable insights for targeted interventions and healthcare policies.

Late-onset Alzheimer disease (LOAD), defined as onset of symptoms after age 65 years, is the most common form of dementia. Few reports investigate incidence rates in large family-based studies in which the participants were selected for family history of LOAD. To determine the incidence rates of dementia and LOAD in unaffected members in the National Institute on Aging Genetics Initiative for Late-Onset Alzheimer Disease/National Cell Repository for Alzheimer Disease (NIA-LOAD/NCRAD) and Estudio Familiar de Influencia Genetica en Alzheimer (EFIGA) family studies. Families with 2 or more affected siblings who had a clinical or pathological diagnosis of LOAD were recruited as a part of the NIA-LOAD/NCRAD Family Study. A cohort of Caribbean Hispanics with familial LOAD was recruited in a different study at the Taub Institute for Research on Alzheimer's Disease and the Aging Brain in New York and from clinics in the Dominican Republic as part of the EFIGA study. Age-specific incidence rates of LOAD were estimated in the unaffected family members in the NIA-LOAD/NCRAD and EFIGA data sets. We restricted analyses to families with follow-up and complete phenotype information, including 396 NIA-LOAD/NCRAD and 242 EFIGA families. Among the 943 at-risk family members in the NIA-LOAD/NCRAD families, 126 (13.4%) developed dementia, of whom 109 (86.5%) met criteria for LOAD. Among 683 at-risk family members in the EFIGA families, 174 (25.5%) developed dementia during the study period, of whom 145 (83.3%) had LOAD. The annual incidence rates of dementia and LOAD in the NIA-LOAD/NCRAD families per person-year were 0.03 and 0.03, respectively, in participants aged 65 to 74 years; 0.07 and 0.06, respectively, in those aged 75 to 84 years; and 0.08 and 0.07, respectively, in those 85 years or older. Incidence rates in the EFIGA families were slightly higher, at 0.03 and 0.02, 0.06 and 0.05, 0.10 and 0.08, and 0.10 and 0.07, respectively, in the same age groups. Contrasting these results with the population-based estimates, the incidence was increased by 3-fold for NIA-LOAD/NCRAD families (standardized incidence ratio, 3.44) and 2-fold among the EFIGA compared with the NIA-LOAD/NCRAD families (1.71). The incidence rates for familial dementia and LOAD in the NIA-LOAD/NCRAD and EFIGA families are significantly higher than population-based estimates. The incidence rates in all groups increase with age. The higher incidence of LOAD can be explained by segregation of Alzheimer disease-related genes in these families or shared environmental risks.

Exercise May Delay Onset of Dementia

Background:Systemic lupus erythematosus (SLE) is a chronic inflammatory disease that can affect any organ of the body. Nervous system involvement of SLE lead to a variety of neurologic and psychiatric manifestations, which are called neuropsychiatric lupus. Cognitive dysfunction may appear as part of neuropsychiatric lupus. There are several papers on the increase in dementia risk in SLE patients, but data are not sufficient and there is little data on whether SLE affects dementia differently depending on the dementia subtype.Objectives:We evaluate dementia incidence and risk in SLE patients in a nationwide population-based cohort and determine whether the risk is different for each dementia subtype.Methods:We identified patients aged 40 years or more, with systemic lupus erythematosus between 2008 and 2014 using the database of the National Health Insurance Service (NHIS) of south Korea. Patients who had previously been diagnosed with dementia were excluded from the study. A total of 11,288 SLE patients and 56,440 control subjects with a 1:5 age- and sex-matching were included in the study. The primary outcome of the study was incident dementia, which was defined by an ICD-10 code and the use of dementia medications. Kaplan-Meier curves and Cox proportional hazards regression analysis were used for the analysis.Results:The incidence rate of dementia was higher in SLE cohort (3.90 per 1,000 person-years) than control cohort (2.73 per 1,000 person-years). Incidence rates of Alzheimer disease and vascular dementia were also higher in SLE cohort than control. SLE patients had a higher risk of dementia compared to control cohorts without SLE (crude hazard ratio 1.43, 95% CI 1.25-1.63). In patients with SLE, the risk of Alzheimer’s disease was 1.4 times higher and the risk of vascular dementia 1.6 times higher than non-SLE control.Conclusion:In this nationwide population-based cohort study, SLE patients had a 1.4-fold higher risk of incident dementia compared to patients without SLE. Further studies are warranted to identify mechanisms of increased risk of dementia in SLE patients. Monitoring of dementia incidence in SLE patients is needed in clinical practice.Disclosure of Interests:None declared

BackgroundHigh‐income countries (HICs) are over‐represented in current global dementia incidence rates, skewing estimates. Variance in diagnostic methods between HICs and low‐ and middle‐income countries (LMICs) is speculated to contribute to the regional differences in rates. Cohort Studies of Memory in an International Consortium (COSMIC) offers a unique opportunity to address these research inequalities by harmonising data from international studies, including representation from LMICs. This study aimed to identify dementia incidence rates by age and sex in various regions worldwide, where data for dementia diagnosis were available.MethodData were obtained from 36 members of COSMIC, representing 28 countries across 6 continents (HICs: Australia, Canada, Faroe Islands, France, Germany, Greece, Italy, Japan, Netherlands, South Korea, Spain, Sweden, &amp; USA; LMICs: Brazil, China, Cuba, Dominican Republic, Ecuador, Indonesia, Malaysia, Mexico, Nigeria, Peru, Philippines, Republic of Congo, &amp; Tanzania). For each member study, we calculated incidence rates for all‐cause dementia. Findings from 14 studies, with a consensus diagnosis are presented in the results. Using an Item Response Theory approach, we are currently calculating a comparable incidence rate for those studies without a consensus diagnosis.ResultConsistent with previous trends, incidence rates (per 100 person‐years) increased with age, from 65‐70 years‐old to 85‐90 years‐old, for both males (i.e., Republic of Congo, 4.41 to 19.57; France, 0.46 to 3.89; USA, 0.17 to 3.22; Spain, 0.31 to 4.22; 65‐70 &amp; 85‐90 cohorts respectively) and females (i.e., Republic of Congo, 3.57 to 15.31; France, 0.45 to 3.72; USA, 0.22 to 4.25; Spain, 0.36 to 4.96; 65‐70 &amp; 85‐90 cohorts respectively). There were no sex differences in incidence rates in younger age groups (60‐65). Among older age groups, however, women tended to have higher incidence rates than men, in some countries (Faroe Islands, Germany, Sweden, and USA).ConclusionGeographical differences in dementia incidence rates likely represent inherent variation among countries, beyond methodological considerations. We are working to expand the range of studies and regions for which we calculate dementia incidence rates. This involves the development of approaches to classify and harmonise incident dementia in studies lacking consensus diagnoses. Doing so will bolster LMIC representation.

Dementia risk amongst older adults with hip fracture receiving general anaesthesia or regional anaesthesia: a propensity-score-matched population-based cohort study