Temporal trends in population attributable fractions of modifiable risk factors for dementia: a time-series study of the English Longitudinal Study of Ageing (2004-2019)

Emerging trends in cognitive impairment and dementia among older populations in Asia: A systematic review

Background

Dementia and cognitive impairment rates in Asia have significant policy implications. Contrary to the existing literature, which primarily focused on the Western region, in this study, we provide novel insights into previously unexplored geographical contexts. We aimed to evaluate the prevalence of cognitive impairment and dementia in Asia.

Methods

Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, we searched six bibliographic databases: Web of Science, Medline, Science Direct, Ovid, Google Scholar, and PubMed. We targeted cross-sectional studies on dementia and cognitive impairment in Asia, published between 2019-23.

Results

Our extensive search yielded 2593 original articles, of which 39 met eligibility criteria. This selection unveiled a significant rise in dementia and cognitive impairment prevalence in Asia, aligning now with trends observed in Western countries - a novel finding that challenges previous assumptions about regional prevalence disparities. The studies predominantly conducted in East Asia (n = 29), along with limited research from Southeast (n = 2), South (n = 7), and Central Asia (n = 1), underscore the geographical gaps in current research. This shift in prevalence patterns is potentially linked to demographic changes, urbanisation, environmental factors, ethnic diversity, and neuroimaging advancements. Identifying modifiable risk factors associated with dementia in these regions presents new avenues for prevention and intervention strategies.

Conclusions

Current dementia research in Asia is concentrated in East Asia, with limited data from Southeast, South, and Central Asia. Comprehensive studies across all parts of Asia are crucial to establishing robust data collection methods and identifying modifiable risk factors. This can help manage and mitigate the growing burden of dementia in these societies.

Trends in Global Burden of Alzheimer's Disease and Other Dementias Attributable to High Fasting Plasma Glucose, 1990-2021

Background and Objectives: Alzheimer's disease and other dementias represent some of the leading public health concerns worldwide. This study aimed to assess the global burden of Alzheimer's disease and other dementias attributable to high fasting plasma glucose in the last decades. Materials and Methods: A descriptive epidemiological study was conducted. The Global Burden of Disease (GBD) study data about deaths and Disability-Adjusted Life Years (DALYs) were used. All figures were presented as age-standardized rates (ASRs). The average annual percent change (AAPC) was computed using the Joinpoint regression analysis. Also, age-period-cohort analysis was performed. Results: A total of 2 million deaths from Alzheimer's disease and other dementias were reported worldwide in 2021, whereby the total number deaths from Alzheimer's disease and other dementias attributable to high fasting plasma glucose was 290,032 (98,900 males and 191,132 females) in 2021. The highest ASRs of burden of Alzheimer's disease and other dementias attributable to high fasting plasma glucose were found in Afghanistan, Iraq, Morocco, Qatar, and the United States of America, while the lowest ASRs were in Belarus and Mongolia. From 1990 to 2021, a significant increase (p < 0.001) was noted in ASRs of deaths and DALYs for Alzheimer's disease and other dementias attributable to high fasting plasma glucose. Looking at the GBD regions, the trends in ASRs for mortality and for DALYs of Alzheimer's disease and other dementias attributable to high fasting plasma glucose between 1990 and 2021 showed a growth 10-fold faster in High-income North America (AAPC = 2.0%, for both equally) and Central Asia (AAPC = 2.4% and AAPC = 2.5%, respectively) than in the region of High-income Asia Pacific (AAPC = 0.1% and AAPC = 0.2%, respectively). The relative risk of mortality and DALYs for Alzheimer's disease and other dementias attributable to high fasting plasma glucose demonstrated statistically significant (p < 0.0001) period and cohort effects, and net drift and local drifts. Conclusions: This study showed an increase in the global burden of Alzheimer's disease and other dementias attributable to high fasting plasma glucose in the last decades. Future successful entire-population strategies targeting high fasting plasma glucose may reduce the burden of a wide range of these diseases.