Temporal changes in the likelihood of dementia and MCI over 18 years in a population sample

Prevalence of Alzheimer's disease dementia in the 50 US states and 3142 counties: A population estimate using the 2020 bridged-race postcensal from the National Center for Health Statistics

INTRODUCTION

This study estimates the prevalence and number of people living with Alzheimer's disease (AD) dementia in 50 US states and 3142 counties.

METHODS

We used cognitive data from the Chicago Health and Aging Project, a population-based study, and combined it with the National Center for Health Statistics 2020 bridged-race population estimates to determine the prevalence of AD in adults ≥65 years.

RESULTS

A higher prevalence of AD was estimated in the east and southeastern regions of the United States, with the highest in Maryland (12.9%), New York (12.7%), and Mississippi (12.5%). US states with the highest number of people with AD were California, Florida, and Texas. Among larger counties, those with the highest prevalence of AD were Miami-Dade County in Florida, Baltimore city in Maryland, and Bronx County in New York.

DISCUSSION

The state- and county-specific estimates could help public health officials develop region-specific strategies for caring for people with AD.

Secular Trends in Dementia Free Cognitive Function in Older Adults: A Systematic Review

BACKGROUND

Although numerous studies have reported a decrease in dementia risk in the last two decades, it is unclear whether dementia-free cognitive function is also changing across generations.

OBJECTIVE

The objective was to systematically evaluate the published data on generational differences in cognitive function in the older population.

METHODS

Searches were performed on PubMed, Embase, and PsychInfo for articles published in English before 20 June 2021. Included studies were from population-based samples that reported generational differences in cognition in individuals without dementia, aged ≥60 years.

RESULTS

28,101 studies were identified and 15 selected covering the period from 1971 to 2015: including studies from China, Europe, and the USA. The results show generally consistent findings of improvements or stability in dementia free cognitive function in later versus earlier born generations, but not for all cognitive domains. Prevalence of mild cognitive impairment and cognitive impairment no dementia has remained stable in the USA, UK, and China over the last two decades.

RESULTS

Prevalence of vascular related mild cognitive impairment has increased in China. Improvements in cognition may only partially be explained by increased educational attainment across generations.

CONCLUSION

This review provides evidence for generational effects in dementia-free cognitive function, predominately stability or improvements in performance, in later compared to earlier born individuals across different world regions. There is an urgent need to determine the factors driving such changes and whether they are being experienced in all world regions, particularly low- and middle-income countries where the burden of cognitive impairment is greatest and rising.

A 9-Year Comparison of Dementia Prevalence in Korea: Results of NaSDEK 2008 and 2017

BACKGROUND

In many high-income Western countries, the prevalence of dementia had been reduced over the past decades.

OBJECTIVE

We investigated whether the prevalence of all-cause dementia, Alzheimer's disease, vascular dementia, and mild cognitive impairment (MCI) had changed in Korea from 2008 to 2017.

METHODS

Nationwide Survey on Dementia Epidemiology of Korea (NaSDEK) in 2008 and 2017 was conducted on representative elderly populations that were randomly sampled across South Korea. Both surveys employed a two-stage design (screening and diagnostic phases) and diagnosed dementia and MCI according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders and the consensus criteria from the International Working Group, respectively. The numbers of participants aged 65 years or older in the screening and diagnostic phases were 6,141 and 1,673 in the NaSDEK 2008 and 2,972 and 474 in the NaSDEK 2017, respectively.

RESULTS

The age- and sex-standardized prevalence of all-cause dementia and Alzheimer's disease showed nonsignificant decrease (12.3% to 9.8%, odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.54-1.48 for all-cause dementia; 7.6% to 6.8%, OR [95% CI] = 0.91 [0.58-1.42] for Alzheimer's disease). Vascular dementia decreased in the young-old population aged less than 75 years (2.7% to 0.001%, OR [95% CI] = 0.04 [0.01-0.15]) and in women (1.9% to 0.5%, OR [95% CI] = 0.27 [0.10-0.72]) while MCI remained stable (25.3% to 26.2%, OR [95% CI] = 1.08 [0.67-1.73]).

CONCLUSION

We found that the prevalence of dementia in Korea showed a nonsignificant decrease between 2008 and 2017.

Population estimate of people with clinical Alzheimer's disease and mild cognitive impairment in the United States (2020-2060)

INTRODUCTION

The estimate of people with clinical Alzheimer's disease (AD) and mild cognitive impairment provides an understanding of the disease burden.

METHODS

We estimated people with cognitive impairment using a quasibinomial regression model in 10,342 participants with cognitive test scores.

RESULTS

The 2020 US Census-adjusted prevalence of clinical AD was 11.3% (95% confidence interval [CI] = 10.7-11.9): 10.0% among non-Hispanic Whites, 14.0% among Hispanics, and 18.6% among non-Hispanic Blacks. We estimate that in 2020, 6.07 (95% CI = 5.75-6.38) million people were living with clinical AD, which increases to 13.85 (95% CI = 12.98-14.74) million in 2060, 423% higher among Hispanics, 192% higher among Blacks, and 63% higher among Whites. However, there are predicted to be more significant increases in later years among those over 85 and women compared to men.

DISCUSSION

The number of people with clinical AD will increase as the "baby boom" generation reaches older ages, exerting a strong upward influence on disease burden.

Long-term community noise exposure in relation to dementia, cognition, and cognitive decline in older adults

INTRODUCTION

Exposure to noise might influence risk of Alzheimer's disease (AD) dementia.

METHODS

Participants of the Chicago Health and Aging Project (≥65 years) underwent triennial cognitive assessments. For the 5 years preceding each assessment, we estimated 5227 participants' residential level of noise from the community using a spatial prediction model, and estimated associations of noise level with prevalent mild cognitive impairment (MCI) and AD, cognitive performance, and rate of cognitive decline.

RESULTS

Among these participants, an increment of 10 A-weighted decibels (dBA) in noise corresponded to 36% and 29% higher odds of prevalent MCI (odds ratio [OR] = 1.36; 95% confidence interval [CI], 1.15 to 1.62) and AD (OR = 1.29, 95% CI, 1.08 to 1.55). Noise level was associated with worse global cognitive performance, principally in perceptual speed (-0.09 standard deviation per 10 dBA, 95% CI: -0.16 to -0.03), but not consistently associated with cognitive decline.

DISCUSSION

These results join emerging evidence suggesting that noise may influence late-life cognition and risk of dementia.

Cognitive function and life quality of patients with moderate-to-severe obstructive sleep apnea-hypopnea syndrome in China

Objective: To investigate the correlation between cognitive function and quality of life in patients with moderate to severe OSAHS, and to further analyze the impact of cognitive domains on QoL in patients with OSAHS.Methods: Pearson analysis was applied to explore the correlation between MoCA score and SAQLI score. It was conducted by collecting the clinical characteristics of patients and the Epworth Sleepiness Scale and Sleep Quality Scale. T-test, a non-parametric test (Mann-Whitney) or chi-square test, and Pearson analysis were used to analyze the relationship between MoCA score and patient clinical characteristics, sleep variables, and SAQLI score.Results: The SAQLI score of the MCI group significantly decreased. Patients in the MCI group had a higher WHR, higher alcohol intake, and a history of hypertension were firmly related to the poor SAQLI (P < 0.05). The Epworth sleepiness scale (ESS) score increased in the MCI group, and the AHI and ODI elevated significantly, which was related to the poorer SAQLI as well (P < 0.05).Conclusion: Cognitive impairment in OSAHS patients is related to QoL reduction.Keywords: cognitive function; Montreal cognitive assessment; obstructive sleep apnea hypopnea syndrome; quality of life; sleep apnea quality of life index.

Association of TDP-43 proteinopathy, cerebral amyloid angiopathy, and Lewy bodies with cognitive impairment in individuals with or without Alzheimer's disease neuropathology

Alzheimer's disease patients typically present with multiple co-morbid neuropathologies at autopsy, but the impact of these pathologies on cognitive impairment during life is poorly understood. In this study, we developed cognitive trajectories for patients with common co-pathologies in the presence and absence of Alzheimer's disease neuropathology. Cognitive trajectories were modelled in a Bayesian hierarchical regression framework to estimate the effects of each neuropathology on cognitive decline as assessed by the mini-mental state examination and the clinical dementia rating scale sum of boxes scores. We show that both TDP-43 proteinopathy and cerebral amyloid angiopathy associate with cognitive impairment of similar magnitude to that associated with Alzheimer's disease neuropathology. Within our study population, 63% of individuals given the 'gold-standard' neuropathological diagnosis of Alzheimer's disease in fact possessed either TDP-43 proteinopathy or cerebral amyloid angiopathy of sufficient severity to independently explain the majority of their cognitive impairment. This suggests that many individuals diagnosed with Alzheimer's disease may actually suffer from a mixed dementia, and therapeutics targeting only Alzheimer's disease-related processes may have severely limited efficacy in these co-morbid populations.