Prevalence of mild cognitive impairment in an urban community in China: a cross-sectional analysis of the Shanghai Aging Study

Pilot implementation of the revised criteria for staging of Alzheimer's disease by the Alzheimer's Association Workgroup in a tertiary memory clinic

INTRODUCTION

We aimed to evaluate the feasibility of the 2024 Alzheimer's Association Workgroup's integrated clinical-biological staging scheme in outpatient settings within a tertiary memory clinic.

METHODS

The 2018 syndromal cognitive staging system, coupled with a binary biomarker classification, was implemented for 236 outpatients with cognitive concerns. The 2024 numeric clinical staging framework, incorporating biomarker staging, was specifically applied to 154 individuals within the Alzheimer's disease (AD) continuum.

RESULTS

The 2024 staging scheme accurately classified 95.5% AD. Among these, 56.5% exhibited concordant clinical and biological stages (canonical), 34.7% demonstrated more advanced clinical stages than biologically expected (susceptible), and 8.8% displayed the inverse pattern (resilient). The susceptible group was characterized by a higher burden of neurodegeneration and inflammation than anticipated from tau, whereas the resilient group showed the opposite.

DISCUSSION

The 2024 staging scheme is generally feasible. A discrepancy between clinical and biological stages is relatively frequent among symptomatic patients with AD.

HIGHLIGHTS

The 2024 AA staging scheme is generally feasible in a tertiary memory clinic. A discrepancy between clinical and biological stages is relatively frequent in AD. The mismatch may be influenced by a non-specific pathological process involved in AD. Individual profiles like aging and lifestyles may contribute to such a mismatch. Matched and mismatched cases converge toward similar clinical outcomes.

Longitudinal trajectories of general cognitive and daily functions in data-driven subtypes of MCI: A longitudinal cohort analysis of older adults

OBJECTIVES

To derive data-driven subtypes of mild cognitive impairment (MCI) and characterize the complicated changes of general cognitive and daily functions over time in MCI subtypes.

METHODS

A total of 813 subjects diagnosed as MCI at baseline from the Alzheimer's Disease Neuroimaging Initiative (ADNI) were included. Data-driven MCI subtypes were derived from group-based multi-trajectory modeling (GBMTM) analyses using longitudinal measurement scores in the cognitive domains of visuospatial function, language, and executive function. General cognitive and daily functions were measured by the Mini-Mental State Examination (MMSE) and the Functional Assessment Questionnaire (FAQ), respectively, whose longitudinal trajectory changes were depicted by Linear mixed models.

RESULTS

Three MCI subtypes were derived, which were defined as "Cognitive decline group", "Mild cognitive decline group" and "No cognitive decline group". The "Mild cognitive decline group" had the highest percentage in the sample (46.2 %), followed by the "No cognitive decline group" (35.2 %). Patients in the "Cognitive decline group" had the highest mean age (74.69 years) at baseline, the highest APOE ε4 carriers (63.2 %), and the greatest dementia conversion rate (77.0 %). The changes in MMSE and FAQ score trajectories were fastest in the "Cognitive decline group" in the first 36 months and most slowly in the "No cognitive decline group".

CONCLUSION

MCI individuals could be subdivided into more fine-grained cognitive subtypes, and identifying these distinct MCI subtypes and their different trajectories of cognitive decline may have important prognostic value for improving clinical course prediction.

Significance of plasma p-tau217 in predicting long-term dementia risk in older community residents: Insights from machine learning approaches

INTRODUCTION

Whether plasma biomarkers play roles in predicting incident dementia among the general population is worth exploring.

METHODS

A total of 1857 baseline dementia-free older adults with follow-ups up to 13.5 years were included from a community-based cohort. The Recursive Feature Elimination (RFE) algorithm aided in feature selection from 90 candidate predictors to construct logistic regression, naive Bayes, bagged trees, and random forest models. Area under the curve (AUC) was used to assess the model performance for predicting incident dementia.

RESULTS

During the follow-up of 12,716 person-years, 207 participants developed dementia. Four predictive models, incorporated plasma p-tau217, age, and scores of MMSE, STICK, and AVLT, exhibited AUCs ranging from 0.79 to 0.96 in testing datasets. These models maintained robustness across various subgroups and sensitivity analyses.

DISCUSSION

Plasma p-tau217 outperforms most traditional variables and may be used to preliminarily screen older individuals at high risk of dementia.

HIGHLIGHTS

Plasma p-tau217 showed comparable importance with age and cognitive tests in predicting incident dementia among community older adults. Machine learning models combining plasma p-tau217, age, and cognitive tests exhibited excellent performance in predicting incident dementia. The training models demonstrated robustness in subgroup and sensitivity analysis.

Association of polygenic risk scores with Alzheimer's disease and plasma biomarkers among Chinese older adults: A community-based study

INTRODUCTION

We examined the associations of polygenic risk score (PRS) with Alzheimer's disease (AD) and plasma biomarkers in the Chinese population.

METHODS

This population-based study used baseline data from MIND-China (2018; n = 4873) and follow-up data from dementia-free individuals (2014-2018; n = 2117). We measured AD-related plasma biomarkers in a subsample (n = 1256). Data were analyzed using logistic and Cox regression models.

RESULTS

We developed PRS with (PRSAPOE) and without (PRSnon- APOE) apolipoprotein E (APOE) gene. In the longitudinal analysis, PRSAPOE was associated with a multivariable-adjusted hazards ratio of 1.91 (95% CI = 1.13-3.23) for AD. PRSAPOE in combination with demographics yielded discriminative (area under the curve [AUC]) and predictive(C-statistic) accuracy of 0.80 (95% confidence interval [CI] = 0.77-0.84) and 0.80 (0.77-0.82), respectively. PRSnon- APOE showed an association with AD risk similar to PRSAPOE. PRSAPOE, but not PRSnon- APOE, was associated with reduced plasma Aβ42/Aβ40 ratio and increased Neurofilament light chain (NfL) (p < 0.05).

DISCUSSION

The PRS with and without APOE gene, in combination with demographics, shows good discriminative and predictive ability for AD. The AD-related pathologies underlie AD risk associated with PRSAPOE.

HIGHLIGHTS

The PRSAPOE and PRSnon- APOE were associated with AD risk in the Chinese population. The PRSAPOE and PRSnon- APOE, in combination with demographics, showed good discriminative and predictive ability for AD. The AD-related pathologies underlie the AD risk associated with PRSAPOE but not PRSnon- APOE.

The relationship between multimorbidity and cognitive function in older Chinese adults: based on propensity score matching

Objective

The goal of this study was to further validate the effect of multimorbidity on cognitive performance in older adults after controlling for confounders using propensity score matching (PSM).

Methods

A cross-sectional survey of older adult people aged 60 years or older selected by convenience sampling was conducted in seven medical institutions, three communities, and five nursing homes in Zunyi City, Guizhou Province. The data collected included general information, health-related information, and Mini-Mental State Examination (MMSE) scores. Variables were controlled for confounders by PSM to analyze differences in cognitive ability between multimorbidity and nonmultimorbidity older adults. Logistic regression and multivariate-adjusted restricted cubic spline (RCS) curves for matched samples were used to assess the relationship between multimorbidity and cognitive decline.

Results

A total of 14,175 respondents were enrolled, and the mean age of the participants included in this study was 71.26 ± 7.1 years, including 7,170 (50. 58%) of the participants were males, 7,005 (49.42%) were females, and 5,482 participants (38.67%) were screened for cognitive decline. After PSM, logistic regression analysis revealed that multimorbidity was a risk factor for cognitive decline (OR = 1.392, 95% CI = 1.271-1.525, p < 0.001). The RCS show that the risk of cognitive decline is always greater in older adults with multimorbidity than in older adults without multimorbidity at the same age. Age, sex, marital status, educational level, monthly income, drinking status, participation in social activities, and exercise were influential factors for cognitive decline in older adults (p < 0.05). The incidence of cognitive decline in older adults with multimorbidity was also greater than that in older adults with one chronic disease (p < 0.001).

Conclusion

The risk of cognitive decline in older adults with multimorbidity is greater than that in older adults without multimorbidity; therefore, the government should strengthen the prevention and treatment of multimorbidity in older adults to further protect their cognitive abilities.

Neurometabolic topography and associations with cognition in Alzheimer's disease: A whole-brain high-resolution 3D MRSI study

INTRODUCTION

Altered neurometabolism, detectable via proton magnetic resonance spectroscopic imaging (1H-MRSI), is spatially heterogeneous and underpins cognitive impairments in Alzheimer's disease (AD). However, the spatial relationships between neurometabolic topography and cognitive impairment in AD remain unexplored due to technical limitations.

METHODS

We used a novel whole-brain high-resolution 1H-MRSI technique, with simultaneously acquired 18F-florbetapir positron emission tomography (PET) imaging, to investigate the relationship between neurometabolic topography and cognitive functions in 117 participants, including 22 prodromal AD, 51 AD dementia, and 44 controls.

RESULTS

Prodromal AD and AD dementia patients exhibited spatially distinct reductions in N-acetylaspartate, and increases in myo-inositol. Reduced N-acetylaspartate and increased myo-inositol were associated with worse global cognitive performance, and N-acetylaspartate correlated with five specific cognitive scores. Neurometabolic topography provides biological insights into diverse cognitive dysfunctions.

DISCUSSION

Whole-brain high-resolution 1H-MRSI revealed spatially distinct neurometabolic topographies associated with cognitive decline in AD, suggesting potential for noninvasive brain metabolic imaging to track AD progression.

HIGHLIGHTS

Whole-brain high-resolution 1H-MRSI unveils neurometabolic topography in AD. Spatially distinct reductions in NAA, and increases in mI, are demonstrated. NAA and mI topography correlates with global cognitive performance. NAA topography correlates with specific cognitive performance.

Serum TRPA1 mediates the association between olfactory function and cognitive function

Background

Olfactory dysfunction was associated with poorer cognition. However, the association between transient receptor potential cation channel subfamily A member 1 (TRPA1) and cognitive function have not been studied. This study aimed to evaluate the mediation effect of TRPA1 on the association between olfactory and cognitive function among Chinese older adults.

Methods

We recruited 121 participants with cognitive impairment (CI) and 135 participants with normal cognition (NC) from a memory clinic and the "Shanghai Aging Study." Olfactory identification of each participant was measured by the Sniffin' Sticks Screening Test 12 (SSST-12). Serum TRPA1 were quantified using the Enzyme-Linked Immunosorbent Assay. The mediation effects of TRPA1 on the association between olfactory function and cognitive function were explored using mediation analysis.

Results

The CI group had a significantly higher proportion of the high level of serum TRPA1 (58.7%) than the NC group (42.2%) (p = 0.0086). After adjusted for gender, age, and years of education, mediation analysis verified that TRPA1 partially mediated the association between SSST-12 and Mini Mental State Examination (MMSE). It also verified that TRPA1 partially mediated the association between the identification of peppermint and MMSE.

Conclusion

Our study emphasizes the mediation role of TRPA1 in the relationship between olfactory and cognitive function among older adults. Further research is necessary to explore the mechanism of TRPA1 on the relationship between olfactory and cognitive decline.

Positive rate and quantification of amyloid pathology with [18F]florbetapir in the urban Chinese population

OBJECTIVES

Amyloid deposition is considered the initial pathology in Alzheimer's disease (AD). Personalized management requires investigation of amyloid pathology and the risk factors for both amyloid pathology and cognitive decline in the Chinese population. We aimed to investigate amyloid positivity and deposition in AD patients, as well as factors related to amyloid pathology in Chinese cities.

METHODS

This cross-sectional multicenter study was conducted in Shanghai and Zhengzhou, China. All participants were recruited from urban communities and memory clinics. Amyloid positivity and deposition were analyzed based on amyloid positron emission tomography (PET). We used partial least squares (PLS) models to investigate how related factors contributed to amyloid deposition and cognitive decline.

RESULTS

In total, 1026 participants were included: 768 participants from the community-based cohort (COMC) and 258 participants from the clinic-based cohort (CLIC). The overall amyloid-positive rates in individuals with clinically diagnosed AD, mild cognitive impairment (MCI), and normal cognition (NC) were 85.8%, 44.5%, and 26.9%, respectively. The global amyloid deposition standardized uptake value ratios (SUVr) (reference: cerebellar crus) were 1.44 ± 0.24, 1.30 ± 0.22, and 1.24 ± 0.14, respectively. CLIC status, apolipoprotein E (ApoE) ε4, and older age were strongly associated with amyloid pathology by PLS modeling.

CONCLUSION

The overall amyloid-positive rates accompanying AD, MCI, and NC in the Chinese population were similar to those in published cohorts of other populations. ApoE ε4 and CLIC status were risk factors for amyloid pathology across the AD continuum. Education was a risk factor for amyloid pathology in MCI. Female sex and age were risk factors for amyloid pathology in NC.

CLINICAL RELEVANCE STATEMENT

This study provides new details about amyloid pathology in the Chinese population. Factors related to amyloid deposition and cognitive decline can help to assess patients' AD risk.

KEY POINTS

• We studied amyloid pathology and related risk factors in the Chinese population. •·The overall amyloid-positive rates in individuals with clinically diagnosed AD, MCI, and NC were 85.8%, 44.5%, and 26.9%, respectively. • These overall amyloid-positive rates were in close agreement with the corresponding prevalence for other populations.

Assessing cognitive impairment in home-dwelling Chinese elders aged 80+: a detailed survey of 13,000 participants focusing on demographic factors, social engagement, and disease prevalence

Introduction

Cognitive Impairment (CI) in the elderly, encompassing conditions ranging from Mild Cognitive Impairment (MCI) to dementia, represents a growing public health concern globally. This study aims to investigate the prevalence and correlates of CI among individuals aged 80 and above.

Methods

The study conducts 13,027 elderly individual's door-to-door surveys, followed by the cross-tabulation of analysis data, logistic regression analysis, and health condition assessments to examine various determinants of CI.

Results

The current study's key findings demonstrate sub-statical correlations between CI and various factors, including educational attainment, marital status, and gender. Pronounced differences are evident between urban and rural demographics. Furthermore, aspects of social engagement, notably communication proficiency and sensory capabilities, exhibit a strong association with CI. Logistic regression analysis highlights that residing in rural areas (Odds Ratio [OR] = 0.637) and being female (OR = 0.71) are linked to a decreased risk of CI. In contrast, behavioral and health-related variables present a complex picture. Specifically, aggressive behavior (Adjusted OR = 1.881) and symptoms of depression (Adjusted OR = 0.549) contrast with conditions such as asthma (OR= 2.857) and cerebral infarction (OR=1.348), which elevate the risk of CI. Intriguingly, hyperlipidemia (OR= 0.671) appears to confer a protective effect against CI.

Conclusion

The study highlights the complexity of factors affecting CI in the elderly, advocating for a comprehensive approach to understanding and managing cognitive health.

Longitudinal trajectory effects of different MCI subtypes on general cognitive and daily functions in a population-based cohort of older adults

OBJECTIVES

To identify different mild cognitive impairment (MCI) phenotypes based on substantial relative impairment in specific cognitive domains and then characterize the complex process of general cognitive and daily functions over time in older adults with these MCI subtypes.

METHODS

A total of 1020 participants with MCI at baseline from the Alzheimer's Disease Neuroimaging Initiative (ADNI) were recruited. MCI subtypes were obtained based on neuropsychological tests in five cognitive domains: memory (M), visuospatial function (V), language (L), processing speed (P), and executive function (E). General cognitive function and daily function were measured by the Mini-Mental State Examination (MMSE) and the Functional Assessment Questionnaire (FAQ), respectively. Linear mixed models were fitted to curve their trajectories across different MCI subtypes.

RESULTS

Considering visuospatial function, subtypes were MO (memory impaired only), M&V (memory and visuospatial function impaired) and M&nV (memory impaired and visuospatial function non-impaired). Similar subtypes and naming rules were obtained based on language, executive function, and processing speed. Further, depending on the number of relative impaired cognitive domains M&S and M&M were obtained. Participants with MO had the highest prevalence in the sample (53.4 %), followed by M&nV (31.1 %). Participants with M&V had the highest mean age (74.69 years) at baseline and the greatest dementia conversion rate (53.2 %). The MMSE and FAQ score trajectories changed most slowly in participants with MO while fastest in those with M&V. Obvious different trajectories of both MMSE and FAQ scores were observed across different subtypes based on visuospatial function and executive function.

CONCLUSION

Compared to MO, individuals with multi-dimensional cognitive impairment have worse general cognitive and daily functions, especially for those with M&V.

The impact of kidney function on plasma neurofilament light and phospho-tau 181 in a community-based cohort: the Shanghai Aging Study

BACKGROUND

The blood-based biomarkers are approaching the clinical practice of Alzheimer's disease (AD). Chronic kidney disease (CKD) has a potential confounding effect on peripheral protein levels. It is essential to characterize the impact of renal function on AD markers.

METHODS

Plasma phospho-tau181 (P-tau181), and neurofilament light (NfL) were assayed via the Simoa HD-X platform in 1189 dementia-free participants from the Shanghai Aging Study (SAS). The estimated glomerular filter rate (eGFR) was calculated. The association between renal function and blood NfL, P-tau181 was analyzed. An analysis of interactions between various demographic and comorbid factors and eGFR was conducted.

RESULTS

The eGFR levels were negatively associated with plasma concentrations of NfL and P-tau181 (B = - 0.19, 95% CI - 0.224 to - 0.156, P < 0.001; B = - 0.009, 95% CI - 0.013 to -0.005, P < 0.001, respectively). After adjusting for demographic characteristics and comorbid diseases, eGFR remained significantly correlated with plasma NfL (B = - 0.010, 95% CI - 0.133 to - 0.068, P < 0.001), but not with P-tau181 (B = - 0.003, 95% CI - 0.007 to 0.001, P = 0.194). A significant interaction between age and eGFR was found for plasma NfL (Pinteraction < 0.001). In participants ≥ 70 years and with eGFR < 60 ml/min/1.73 m2, the correlation between eGFR and plasma NfL was significantly remarkable (B = - 0.790, 95% CI - 1.026 to - 0,554, P < 0.001).

CONCLUSIONS

Considering renal function and age is crucial when interpreting AD biomarkers in the general aging population.

Adequate dietary magnesium intake may protect females but not males older than 55 years from cognitive impairment

BACKGROUND

Magnesium is an essential nutrient required to maintain brain health throughout life, and adequate magnesium intake is positively associated with cognitive performance in older adults. However, sex differences in magnesium metabolism have not been adequately assessed in humans.

OBJECTIVES

We investigated sex differences in the effect of dietary magnesium intake and the risk of different types of cognitive impairment in older Chinese adults.

METHODS

We collected and assessed dietary data and cognitive function status in people aged 55 years and older in northern China who participated in the Community Cohort Study of Nervous System Diseases from 2018 to 2019 to explore the relationship between dietary magnesium intake and the risk of each type of mild cognitive impairment (MCI) in sex-specific cohorts of older adults.

RESULTS

The study included 612 people: 260 (42.5%) men and 352 (57.5%) women. Logistic regression results showed that for the total sample and women's sample, high dietary magnesium intake reduced the risk of amnestic MCI (ORtotal = 0.300; ORwomen = 0.190) and multidomain amnestic MCI (ORtotal = 0.225; ORwomen = 0.145). The results of restricted cubic spline analysis showed that the risk of amnestic MCI (ptotal = 0.0193; pwomen = 0.0351) and multidomain amnestic MCI (ptotal = 0.0089; pwomen = 0.0096) in the total sample and women's sample gradually decreased with increasing dietary magnesium intake.

CONCLUSIONS

The results suggest that adequate magnesium intake may have a preventive effect against the risk of MCI in older women.

Effect of Multimodal Intervention in Individuals with Mild Cognitive Impairment: A Randomized Clinical Trial in Shanghai

Background

Previous trials have indicated that multimodal training could improve cognitive functions and moods in individuals with mild cognitive impairment (MCI). However, evidence was mainly obtained from studies in high-income countries.

Objective

This trial aims to investigate the efficacy, safety, and potential mechanism of a multimodal intervention on cognitive function in individuals with MCI living in a community.

Methods

In this single-blind, randomized controlled trial, 120 participants with MCI were randomly assigned to either the intervention group or the control group. The intervention group received the multimodal intervention, while the control group received regular health education. Neuropsychological tests and magnetic resonance imaging (MRI) were conducted at baseline and after the 12-week intervention.

Results

Fifty-nine and fifty-seven participants respectively in the intervention and control groups completed the trial. The intervention group shown improvements in primary outcome, Mini-Mental State Exam (MMSE) total score (mean difference -0.96, 95% CI [-1.58, -0.34], p = 0.003), and secondary outcomes: MMSE recall (-0.39, 95% CI [-0.71, -0.07], p = 0.019), MMSE language (-0.26, 95% CI [-0.44, -0.07], p = 0.007), Auditory Verbal Learning Test instantaneous memory (-3.30, 95% CI [-5.70, -0.89], p = 0.008), Digit Symbol Substitution Test total score (-2.91, 95% CI [-5.67, -0.15], p = 0.039), digit span forwards (-1.25, 95% CI [-1.93, -0.56], p < 0.001), and Digit Span Test (-1.33, 95% CI [-2.33, -0.34], p = 0.009) compared to the control group. Improvements were observed in structural and functional connectivity related to language, concentration, executive function, memory, and recall functioning via MRI in the intervention group.

Conclusions

The multimodal intervention improved cognitive function in individuals with MCI in cognitive performance and neuroimaging.

Development and Validation of an Automatic Computerized Neurocognitive Battery in Chinese

OBJECTIVES

Neuropsychological test batteries, which accurately and comprehensively assess cognitive functions, are a crucial approach in the early detection of and interventions for cognitive impairments. However, these tests have yet to gain wide clinical application in China owing to their complexity and time-consuming nature. This study aimed to develop the Computerized Neurocognitive Battery for Chinese-Speaking participants (CNBC), an autorun and autoscoring cognitive assessment tool to provide efficient and accurate cognitive evaluations for Chinese-Speaking individuals.

METHODS

The CNBC was developed through collaboration between clinical neurologists and software engineers. Qualified volunteers were recruited to complete CNBC and traditional neurocognitive batteries. The reliability and validity of the CNBC were evaluated by analyzing the correlations between the measurements obtained from the computerized and the paper-based assessment and those between software-based scoring and manual scoring.

RESULTS

The CNBC included 4 subtests and an autorun version. Eighty-six volunteers aged 51-82 years with 7-22 years of education were included. Significant correlations (0.256-0.666) were observed between paired measures associated with attention, executive function, and episodic memory from the CNBC and the traditional paper-based neurocognitive batteries. This suggests a strong construct validity of the CNBC in assessing these cognitive domains. Furthermore, the correlation coefficients between manual scoring and system scoring ranged from 0.904-1.0, indicating excellent inter-rater reliability for the CNBC.

INTERPRETATION

A novel CNBC equipped with automated testing and scoring features was developed in this study. The preliminary results confirm its strong reliability and validity, indicating its promising potential for clinical utilization.

Prevalence and associated factors of mild cognitive impairment among middle-aged and older adults: Results of the first phase of Ardakan Cohort Study on Aging

Background and Aims

Data on mild cognitive impairment (MCI) in low- to middle-income countries are still being determined, despite the fact that most future older adults are expected to reside in these regions. This study aimed to investigate the prevalence and associated factors of MCI in Iran.

Methods

A cross-sectional study was conducted on 4938 community-dwelling subjects aged 50 years or above in the first wave of the Ardakan Cohort Study on Aging. MCI was evaluated using the Mini-Mental State Examination (MMSE) and the Abbreviated Mental Test Score (AMTS) in literate and illiterate individuals. The relationship between factors associated with the odds of MCI was assessed through logistic regression.

Results

The prevalence of MCI among all participants, the literates and illiterates, was 15.8%, 6.3%, and 36.4%, respectively. It was found that failure to accomplish any of the MMSE or AMTS items was significantly related to MCI (p < 0.001). Age ([odds ratio (OR): 1.05; p < 0.001 in the literates], [OR: 1.06; p < 0.001 in the illiterates]), sex (OR: 0.13; p < 0.001 in the illiterates), history of stroke ([OR: 2.86; p = 0.006 in the literates], [OR: 2.04; p = 0.045 in the illiterates]), and depression ([OR: 1.87; p < 0.001 in the literates], [OR: 1.41; p = 0.008 in the illiterates]) were significantly associated with MCI.

Conclusion

This study highlights the significant associations between age, education, depression, stroke, and MCI in Iranian participants. These findings emphasize the need for targeted interventions in low-literacy populations, mental health screening, and stroke prevention strategies to mitigate the burden of MCI and enhance cognitive health.

Plasma Aβ42:Aβ40 ratio as a biomarker for cognitive impairment in haemodialysis patients: a multicentre study

Background

Mild cognitive impairment (MCI) and dementia are more prevalent in patients undergoing haemodialysis (HD). Although the cerebrospinal fluid amyloid beta (Aβ) and tau (τ) have proven to be valid biomarkers for the diagnosis of Alzheimer's disease (AD) in the general population, the roles of plasma Aβ and τ for the diagnosis of cognitive impairment in HD patients remain unknown.

Methods

We conducted a cross-sectional study including patients receiving HD in three hospitals in Shanghai. All patients completed the Montreal Cognitive Assessment-Basic (MoCA-B). To validate the effectiveness of the MoCA-B score for screening MCI, a subset group underwent neuropsychological batteries. Serum proteomes were compared in HD patients with normal cognitive function and dementia. Plasma Aβ42, Aβ40 and total τ were measured using a single molecule array.

Results

A total of 311 HD patients were enrolled (mean age 63 years, 55% male). The best cut-off score of MoCA-B for differentiating MCI and normal cognition was 24, with an area under the curve of 0.94. Serum proteomics revealed that neurodegenerative pathways related to AD were enriched in HD patients with dementia. The plasma Aβ42:Aβ40 ratio was significantly reduced in patients with MCI and dementia and was independently associated with cognitive function after adjusting for age, sex and education levels.

Conclusions

We validated the MoCA-B as an optimal cognitive function screening instrument for MCI in HD patients. The plasma Aβ42:Aβ40 ratio was a potential biomarker in distinguishing normal cognition, MCI and dementia in HD populations.

Plasma p-tau217, p-tau181, and NfL as early indicators of dementia risk in a community cohort: The Shanghai Aging Study

INTRODUCTION

Blood biomarkers showed values for predicting future cognitive impairment. Evidence from the community-based cohort was limited only in high-income countries.

METHODS

This study included 1857 dementia-free community residents recruited in 2009-2011 and followed up in waves 2014-2016 and 2019-2023 in the Shanghai Aging Study. We intended to explore the relationships of baseline plasma ALZpath phosphorylated tau 217 (p-tau217), p-tau181, neurofilament light chain (NfL) with follow-up incident dementia, Alzheimer's disease (AD), and amyloidosis.

RESULTS

Higher concentrations of plasma p-tau217, p-tau181, and NfL were correlated to higher decline speed of Mini-Mental State Examination score, and higher risk of incident dementia and AD. The p-tau217 demonstrated a significant correlation with longitudinal neocortical amyloid-beta (Aβ) deposition (r = 0.57 [0.30, 0.76]) and a high accuracy differentiating Aβ+ from Aβ- at follow-ups (area under the receiver operating characteristic curve = 0.821 [0.703, 0.940]).

DISCUSSION

Plasma p-tau217 may be an early predictive marker of AD and Aβ pathology in older community-dwelling individuals.Highlights: Plasma p-tau217, p-tau181, and NfL were positively associated with long-term cognitive decline and risk of incident dementia.Plasma p-tau217 showed a better performance distinguishing Aβ+ individuals from Aβ- individuals at follow-ups.Plasma NfL may be a suitable predictor of general cognitive decline in older community-dwelling individuals.

Olfactory function, neurofilament light chain, and cognitive trajectory: A 12-year follow-up of the Shanghai Aging Study

This study aimed to determine whether blood neurofilament light chain (NfL) modifies the association of olfactory dysfunction (OD) with long-term cognitive decline. A total of 1125 non-demented older adults in the Shanghai Aging Study were evaluated for baseline olfaction (12-item Sniffin' Sticks Smell Test) and cognitive trajectory by a 12-year follow-up. Baseline blood NfL was quantified using Single Molecular Array assay, and dichotomized into low and high levels based on the median value of concentration. The Mini-Mental State Examination (MMSE) and Telephone Interview for Cognitive Status-40 were used to assess participants' cognitive function. Cognitive decline was ascertained when dementia was diagnosed or documented in the medical record during follow-up, or the MMSE declining rate (slope) was 1.0 SD larger than the group mean. OD participants presented a steeper trajectory of MMSE score (p interaction = 0.004) and a high risk of cognitive decline (adjusted HR [95% CI], 1.82 [1.11, 2.98]) only in those with high NfL. Participants with combined OD and high NfL showed the highest risk of cognitive decline (adjusted HR, 2.43 [1.20, 4.92]). OD, especially in combination with high blood NfL concentration, may be able to identify individuals who later incur cognitive deterioration.

Higher Adherence to the AMED, DASH, and CHFP Dietary Patterns Is Associated with Better Cognition among Chinese Middle-Aged and Elderly Adults

The available evidence regarding the association between adherence to the Alternate Mediterranean Diet (AMED) and Dietary Approaches to Stop Hypertension (DASH) dietary patterns and cognitive performance exhibits inconsistency, and its applicability within the Asian population remains uncertain. The association between adherence to the Chinese Food Pagoda (CHFP) and cognitive function is also unknown. In this study, we aimed to assess the association between adherence to the AMED, DASH, and CHFP different dietary patterns and cognitive function. The study included 3353 Chinese adults aged 55 years and over from the China Health and Nutrition Survey (CHNS) in 2006. A 24 h dietary recall over three consecutive days was used to collect dietary information. Dietary patterns included AMED, DASH, and CHFP. A subset of items from the Telephone Interview for Cognitive Status-Modified was used for cognitive screening. Poor cognitive performance was defined as a global cognitive function score < 7. Binary logistic regression was used to estimate the association between adherence to the three different dietary patterns and cognitive function. Binary logistic regression analysis showed that there is a negative association between higher adherence to the AMED, DASH, and CHFP and poorer cognitive performance (AMED: OR = 0.594, 95% CI = 0.458-0.771, p < 0.001; DASH: OR = 0.652, 95% CI = 0.504-0.843, p = 0.001; CHFP: OR = 0.599, 95% CI = 0.417-0.861, p = 0.006). There was a significant interaction between each of the three dietary patterns and residential regions (AMED: p for interaction = 0.045; DASH: p for interaction = 0.003; CHFP: p for interaction < 0.001). Higher adherence to the AMED, DASH, and CHFP dietary patterns was inversely associated with poor cognition in Chinese middle-aged and elderly adults, particularly among urban residents.

Head-to-head comparison of plasma and PET imaging ATN markers in subjects with cognitive complaints

BACKGROUND

Gaining more information about the reciprocal associations between different biomarkers within the ATN (Amyloid/Tau/Neurodegeneration) framework across the Alzheimer's disease (AD) spectrum is clinically relevant. We aimed to conduct a comprehensive head-to-head comparison of plasma and positron emission tomography (PET) ATN biomarkers in subjects with cognitive complaints.

METHODS

A hospital-based cohort of subjects with cognitive complaints with a concurrent blood draw and ATN PET imaging (18F-florbetapir for A, 18F-Florzolotau for T, and 18F-fluorodeoxyglucose [18F-FDG] for N) was enrolled (n = 137). The β-amyloid (Aβ) status (positive versus negative) and the severity of cognitive impairment served as the main outcome measures for assessing biomarker performances.

RESULTS

Plasma phosphorylated tau 181 (p-tau181) level was found to be associated with PET imaging of ATN biomarkers in the entire cohort. Plasma p-tau181 level and PET standardized uptake value ratios of AT biomarkers showed a similarly excellent diagnostic performance for distinguishing between Aβ+ and Aβ- subjects. An increased tau burden and glucose hypometabolism were significantly associated with the severity of cognitive impairment in Aβ+ subjects. Additionally, glucose hypometabolism - along with elevated plasma neurofilament light chain level - was related to more severe cognitive impairment in Aβ- subjects.

CONCLUSION

Plasma p-tau181, as well as 18F-florbetapir and 18F-Florzolotau PET imaging can be considered as interchangeable biomarkers in the assessment of Aβ status in symptomatic stages of AD. 18F-Florzolotau and 18F-FDG PET imaging could serve as biomarkers for the severity of cognitive impairment. Our findings have implications for establishing a roadmap to identifying the most suitable ATN biomarkers for clinical use.

Metagenomic association analysis of cognitive impairment in community-dwelling older adults

The gut microbiota is reportedly involved in neurodegenerative disorders, and exploration of differences in the gut microbiota in different cognitive status could provide clues for early detection and intervention in cognitive impairment. Here, we used data from the Taizhou Imaging Study (N = 516), a community-based cohort, to compare the overall structure of the gut microbiota at the species level through metagenomic sequencing, and to explore associations with cognition. Interestingly, bacteria capable of producing short-chain fatty acids (SCFAs), such as Bacteroides massiliensis, Bifidobacterium pseudocatenulatum, Fusicatenibacter saccharivorans and Eggerthella lenta, that can biotransform polyphenols, were positively associated with better cognitive performance (p < 0.05). Although Diallister invisus and Streptococcus gordonii were not obviously related to cognition, the former was dominant in individuals with mild cognitive impairment (MCI), while the later was more abundant in cognitively normal (CN) than MCI groups, and positively associated with cognitive performance (p < 0.05). Functional analysis further supported a potential role of SCFAs and lactic acid in the association between the gut microbiota and cognition. The significant associations persisted after accounting for dietary patterns. Collectively, our results demonstrate an association between the gut microbiota and cognition in the general population, indicating a potential role in cognitive impairment. The findings provide clues for microbiome biomarkers of dementia, and insight for the prevention and treatment of dementia.

Apolipoprotein E ε4 Modifies the Effect of Possible Anticholinergic Drugs on Incident Dementia: The Shanghai Aging Study

OBJECTIVES

To validate the hypothesis that apolipoprotein E (APOE) ε4 modifies the effect of possible anticholinergic drugs (PACDs) on incident dementia among older adults.

DESIGN

A population-based prospective study.

SETTING AND PARTICIPANTS

Dementia-free older adults in an urban community in Shanghai, China.

METHODS

At baseline, PACDs were defined according to the Anticholinergic Cognitive Burden Scale. Standard daily dose (SDD) of PACDs was calculated. A battery of neuropsychological tests was used to assess cognition and the consensus diagnosis was conducted for incident dementia and Alzheimer's disease (AD). Multivariate Cox regression models were used to examine the association between PACD use and the risk of dementia and AD in APOE ε4 carriers and noncarriers.

RESULTS

We followed 1406 dementia-free participants for a median of 5.3 years and defined 117 incident dementia cases, among which 89 were AD. Only in APOE ε4 carriers was PACD use associated with incident dementia [hazard ratio (HR) 5.71; 95% CI 2.04-15.94] and AD (HR 5.73; 95% CI 1.77-18.54); SDD was positively associated with incident dementia (HR 2.42; 95% CI 1.32-4.44) and AD (HR 2.16; 95% CI 1.06-4.41).

CONCLUSIONS AND IMPLICATIONS

Using PACDs requires judicious consideration for the potential risk of dementia and AD in older adults carrying APOE ε4.

Oral microbiome in older adults with mild cognitive impairment

The association between the oral microbiome and mild cognitive impairment (MCI) remains unclear. This study aimed to investigate such an association among Chinese older adults. Participants without dementia were recruited from the community. A battery of neuropsychological tests was administered to evaluate the cognitive function. The diagnosis of MCI was based on Peterson's criteria. The non-stimulated saliva was collected to extract sequences of the oral microbiome. Forty-seven MCI and 47 cognitively normal participants were included. There was significant difference in alpha diversity and insignificant difference in beta diversity between the two groups of participants. Compared with the cognitively normal group, Gemella haemolysans and Streptococcus gordonii were two significantly decreased species while Veillonella unclassified_Veillonella and Fusobacterium sp._HMT_203 were two significantly increased species in the MCI group. The richness of Gemella haemolysans presented the best discriminate value for MCI with the AUC (Area Under Curve) of 0.707, a cut-off value of 0.008 for relative abundance, the sensitivity of 63.8% and specificity of 70.2%. The dysbiosis of oral microbiome and relative abundance of Gemella haemolysans was significantly associated with MCI. Further studies were needed to develop new treatment strategies targeting the oral microbiome for cognitive impairment.

Education, neighborhood environment, and cognitive decline: Findings from two prospective cohort studies of older adults in China

INTRODUCTION

The impacts of education on cognitive decline across different neighborhood environments (NEs) have rarely been studied.

METHODS

We investigated and compared the associations between educational attainment and cognitive decline using data of 1286 participants from the Taizhou Imaging Study (TIS) and the Shanghai Aging Study (SAS).

RESULTS

Compared with low-educated participants, in TIS with disadvantaged NE, high-educated participants manifested a significantly slower decline in global cognition (.062 Z score per year, P < .001), memory (.054 Z score per year, P < .05), and attention (.065 Z score per year, P < .01), whereas in SAS with advanced NE, highly educated individuals exhibited a slower decline only in attention (.028 Z score per year, P < .05).

DISCUSSION

We observed the additive effect of educational attainment and NE on cognitive decline in older adults. Education is especially important for maintaining cognitive health in a disadvantaged environment.

The Joint Effect of Body Mass Index and Serum Lipid Levels on Incident Dementia among Community-Dwelling Older Adults

OBJECTIVES

This study aimed to explore the joint effect of body mass index (BMI) and serum lipids levels on incident dementia.

METHODS

We prospectively followed up with 1,627 dementia-free community residents aged ≥60 for 5.7 years on average. At baseline, weight, and height were measured, and total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were detected in serum. Demographic characteristics were collected through questionnaires. Dementia was based on consensus diagnosis of neurologists and neuropsychologists using DSM-IV criteria. Additive Cox proportional model was used to assess the exposure-response relationship between BMI and serum lipid levels and dementia risk. Interactions and further classifications of BMI and serum lipid levels were further presented by bivariate surface models and decision-tree models.

RESULTS

The joint effects of TC with BMI, TG with BMI, and LDL-C with BMI on the risk of incident dementia shared a similar pattern, different from their independent exposure-response curves. The joint effect of HDL-C with BMI showed an S-surface but without statistical significance. Participants with TC<5.4 mmol/L and BMI<21 kg/m2 (Hazard Ratio(HR) 1.93, 95% Confidence Interval (CI) 1.05-3.53), TC<5.4 mmol/L and BMI≥21 kg/m2 (HR 1.73, 95% CI 1.09-2.72), and TC≥5.4 mmol/L and BMI<21 kg/m2 (HR 4.02, 95% CI 2.10-7.71) were identified to have the increased risk of incident dementia compared to those with TC≥5.4 mmol/L and BMI≥21 kg/m2. Participants with TG<1.7 mmol/L and BMI<21 kg/m2 had an increased risk of incident dementia compared to those with TG≥1.7 mmol/L and BMI≥21 kg/m2 (HR 1.98, 95%CI 1.17-3.3). Participants with LDL-C≥3.3 mmol/L and BMI<21 kg/m2 were identified to have an increased risk of incident dementia compared to those with LDL-C≥3.3 mmol/L and BMI≥21 kg/m2 (HR 3.33, 95%CI 1.64-6.78).

CONCLUSIONS

Our study showed that low BMI combined with low or high levels of serum lipids may increase the risk of dementia among older adults. This finding suggests the potential impacts of these two metabolic indexes on the risk of dementia.

Association between occlusal support and cognitive impairment in older Chinese adults: a community-based study

Introduction

The loss of occlusal support due to tooth loss is associated with systemic diseases. However, there was little about the association between occlusal support and cognitive impairment. The cross-sectional study aimed to investigate their association.

Methods

Cognitive function was assessed and diagnosed in 1,225 community-dwelling adults aged 60 years or older in Jing'an District, Shanghai. Participants were diagnosed with mild cognitive impairment (MCI) by Peterson's criteria, or dementia, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. We determined the number of functional occlusal supporting areas according to Eichner classifications. We used multivariate logistic regression models to analyze the relationship between occlusal support and cognitive impairment and mediation effect models to analyze the mediation effect of age.

Results

Six hundred sixty participants were diagnosed with cognitive impairment, averaging 79.92 years old. After adjusting age, sex, education level, cigarette smoking, alcohol drinking, cardiovascular disease, and diabetes, individuals with poor occlusal support had an OR of 3.674 (95%CI 1.141-11.829) for cognitive impairment compared to those with good occlusal support. Age mediated 66.53% of the association between the number of functional occlusal supporting areas and cognitive impairment.

Discussion

In this study, cognitive impairment was significantly associated with the number of missing teeth, functional occlusal areas, and Eichner classifications with older community residents. Occlusal support should be a significant concern for people with cognitive impairment.

Mild cognitive impairment among rural-dwelling older adults in China: A community-based study

BACKGROUND

Epidemiological studies of mild cognitive impairment (MCI) and subtypes of MCI have rarely focused on rural residents in China.

METHODS

This population-based study included 5068 participants (age ≥60 years) who were living in rural communities. We defined MCI, amnestic MCI (aMCI), and non-amnestic MCI (naMCI) following the Petersen's criteria that integrated neuropsychological assessments with in-person clinical evaluations.

RESULTS

The overall prevalence of MCI, aMCI, and naMCI was 26.48%, 22.30%, and 4.18%, respectively. The prevalence of MCI increased with age. The adjusted odds ratio (OR) of MCI was 0.71 (95% confidence interval [CI] 0.61 to 0.82) for primary school (vs. illiteracy), 0.30 (0.24 to 0.39) for middle school or above, 1.35 (1.09 to 1.67) for being farmers, 0.65 (0.54 to 0.78) for alcohol consumption, 1.43 (1.20 to 1.70) for stroke history, and 1.14 (0.95 to 1.36) for any apolipoprotein E (APOE) ε4 allele (vs ε3/ε3).

CONCLUSIONS

MCI affects over one-fourth of rural older adults in China. Overall MCI was associated with demographic factors, non-alcohol consumption, and stroke, but not with APOE genotype and cardiometabolic factors.

Urbanization and Cognitive Function Among Middle-Aged and Old Adults in China

OBJECTIVES

Our study examined the effect of urbanization on cognitive function and its possible pathways among Chinese middle-aged and older adults independent of the influence of health-selective migration.

METHODS

Using data from the China Health and Retirement Longitudinal Study, we compared cognitive function among three groups (urbanized-rural residents, rural nonmigrants, and urban nonmigrants). Logistic regression and structural equation models were applied to explore the impact of urbanization on cognitive function and the potential mechanisms.

RESULTS

Compared with the urbanized-rural group, urban nonmigrants had better cognitive function, with a significant coefficient of 1.56 (95% CI: 1.22, 1.89) for global cognition scores and 0.37 (95% CI: 0.22, 0.53) for episodic memory scores. The rural nonmigrants had the worst cognitive function (β = -0.79, 95% CI: -1.04, -0.55) and lower scores of mental intactness (β = -0.65, 95% CI: -0.84, -0.57) and episodic memory (β = -0.14, 95% CI: -0.26, -0.03). The association between urbanization and cognitive function was mainly mediated by income and living conditions among middle-aged and older adults.

DISCUSSION

Rural people who experienced planned urbanization in China had higher cognitive scores than rural non-migrants. Urbanization could thus have a beneficial and cumulative effect on cognitive function. Improvements in living conditions and changes in income are the main drivers behind the relationship. However, urbanization could compensate for the negative impact on cognitive function from disadvantaged early-life conditions, but it cannot completely eliminate the gap between urbanized-rural people and urban nonmigrants.

Dietary calcium and magnesium intake and risk for incident dementia: The Shanghai Aging Study

Introduction

Calcium (Ca), magnesium (Mg), or the calcium to magnesium (Ca:Mg) ratio may affect the risk of dementia via complex mechanisms. The aim of this study was to evaluate the association of dietary Ca, Mg, and Ca:Mg ratio with dementia risk at the prospective phase of the Shanghai Aging Study.

Methods

We analyzed data from 1565 dementia-free participants living in an urban community who had measurements of dietary Ca and Mg intake derived from a food frequency questionnaire at baseline and incident dementia during follow-up.

Results

Over the 5-year follow-up, 162 (10.4%) participants were diagnosed with incident dementia by Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria. Participants with the lowest tertile of dietary Ca (<339.1 mg/day) and Mg (<202.1 mg/day) had the highest incidence rates of dementia (3.3/100 person-years for Ca, 3.3/100 person-years for Mg) compared to those with higher Ca and Mg intake. In the subgroup with Ca:Mg ratios ≤ 1.69, Mg intake >267.5 mg/day was related to an increased risk for dementia (adjusted hazard ratio: 3.97, 95% confidence interval: 1.29-12.25).

Conclusions

Our findings suggest that high dietary intake of Mg is associated with an increased risk of dementia mainly among older adults with low Ca:Mg intake ratios. Proper balance of Ca to Mg in the diet may be critical to the relationship between Mg intake and risk of dementia.

Highlights

Participants with the lowest tertile of dietary calcium (Ca) and magnesium (Mg) had the highest incidence rates of dementia.In the subgroup with Ca:Mg ratios ≤1.69, Mg intake >267.5 mg/day was related to an increased risk for dementia.Balance of Ca to Mg in diet may be critical to the relationship between Mg intake and risk of dementia.

Finger Tapping Test for Assessing the Risk of Mild Cognitive Impairment

Aim

A testing method for early diagnosis of Mild cognitive dementia (MCI) that can be easily applied in clinical practice was investigated in this study. We examined whether MCI risk can be determined through finger movements.

Methods

Between 2013 and 2020, 1097 individuals were screened. After applying propensity-score matching to adjust for variability between the groups, 173 individuals each in the mild cognitive impairment and control groups were selected. Thereafter, differences between groups in mean values of parameters extracted from finger tap movements were determined using unpaired t-test and effect size. Furthermore, area under the curve, sensitivity, and specificity were calculated from the receiver operating characteristic curve for parameters with significant difference.

Results

A significant difference was observed, especially in the number of taps in the MCI group compared with that in the control group (p < .001; 95% CI, -12.7 to -8.8; r = 0.51). A cut-off value of 30 taps was applied (sensitivity, 0.77; specificity, 0.67; AUC, 0.79). Significant differences were also observed in rhythm-related parameters.

Conclusions

These parameters might be useful for capturing MCI risk. Finger taps are easily measured and may be suitable for screening large populations. This tool might be used as a supplemental method to increase the sensitivity of traditional cognitive tests.

Prevalence and associated factors of cognitive impairment among the elderly population: A nationwide cross-sectional study in China

Background

Cognitive impairments are associated with increased risk for progression to dementia. In China, limited surveys have been conducted to estimate the national prevalence and risk factors associated with cognitive impairment in China. This study aims to assess the national prevalence and modifiable risk factors for cognitive impairments in the Chinese elderly population.

Methods

This cross-sectional study was based on the 2018 China Health and Retirement Longitudinal Study. The Mini Mental State Examination (MMSE) is recommended to test for cognitive impairment. Univariate and multivariate logistic regression models were used in assessing risk factors for cognitive impairments in the Chinese elderly population.

Results

A total of 3768 participants aged 60 years or older were enrolled in this study. The national prevalence of cognitive impairments was 22.24% in China, and the prevalence of cognitive impairment was higher in the south-west region than in the north region (29.94 vs. 16.53%, p < 0.05). The risk for cognitive impairments was higher in the following participants: not married or not living with spouse relative to married with spouse present (OR = 1.39, 95% CI, 1.15-1.70; p = 0.001), nap duration of ≥ 90 min relative to 30-60 min (OR = 1.54, 95% CI, 1.20-1.98; p = 0.001), sleep duration of ≥ 8 h relative to 6-8 h (OR = 1.73, 95% CI, 1.29-2.31; p < 0.001), and depression relative to no depression (OR = 1.67, 95% CI, 1.41-1.97; p < 0.001). The risk of cognitive impairment was lower in participants living in the urban areas relative to the rural areas (OR = 0.57, 95% CI, 0.47-0.69; p < 0.001) and consuming alcohol once a month relative to never consuming alcohol (OR = 0.69, 95% CI, 0.51-0.94; p = 0.02).

Conclusion

Cognitive impairment prevalence was high in the Chinese elderly population. The potentially modifiable risk factors for cognitive impairment should be further assessed in the development of interventions for the elderly Chinese population.

Interactive Effects of Methionine and Lead Intake on Cognitive Function among Chinese Adults

The association between methionine intake and cognitive function is inconclusive. We aimed to assess the association between methionine intake and cognitive function in Chinese adults and to explore the interaction between methionine and lead intake. Data from 4852 adults aged ≥55 years from the China Health and Nutrition Survey were used. Cognitive function was measured in 1997, 2000, 2004, and 2006. A 3-day, 24-hour recall was used to assess methionine and lead intake from different protein sources. Multivariable mixed linear regression was used in the analyses. Total methionine intake was positively correlated with cognition. There was a significant interaction between animal methionine and lead intakes. In subgroup analyses, across the quartiles of animal methionine intake, the regression coefficients (95% CI) for global cognition were 0.00, 0.57 (0.17 to 0.98), 1.18 (0.73 to 1.62), and 1.80 (1.31 to 2.29), respectively, while they were 0.00, -0.73 (-1.12 to -0.34), -0.83 (-1.26 to -0.41), and -1.72 (-2.22 to -1.22) across the quartiles of plant methionine intake, respectivelyThe association between animal methionine intake and cognition was stronger among adults with a low lead intake. In conclusion, animal methionine and plant methionine intake were positively and inversely associated with cognition, respectively. Lead intake modified the association between animal methionine intake and cognition.

Plasma Aβ42/Aβ40 and p-tau 181 Predict Long-Term Clinical Progression in a Cohort with Amnestic Mild Cognitive Impairment

BACKGROUND

Previous studies reported the value of blood-based biomarkers in predicting Alzheimer disease (AD) progression among individuals with different disease stages. However, evidence regarding the value of these markers in those with amnestic mild cognitive impairment (aMCI) is insufficient.

METHODS

A cohort with 251 aMCI individuals were followed for up to 8 years. Baseline blood biomarkers were measured on a single-molecule array platform. Multipoint clinical diagnosis and domain-specific cognitive functions were assessed to investigate the longitudinal relationship between blood biomarkers and clinical AD progression.

RESULTS

Individuals with low Aβ42/Aβ40 and high p-tau181 at baseline demonstrated the highest AD risk (hazard ratio = 4.83, 95% CI 2.37-9.86), and the most dramatic decline across cognitive domains. Aβ42/Aβ40 and p-tau181, combined with basic characteristics performed the best in predicting AD conversion (AUC = 0.825, 95% CI 0.771-0.878).

CONCLUSIONS

Combining Aβ42/Aβ40 and p-tau181 may be a feasible indicator for AD progression in clinical practice, and a potential composite marker in clinical trials.

Association between physical activity and mild cognitive impairment in community-dwelling older adults: Depression as a mediator

Introduction

Dementia has become a public health priority and is irreversible. Mild cognitive impairment (MCI), an intermediate state between normal cognition and dementia, is the prime time for early diagnosis and intervention. The activities of daily living of dementia patients are usually insufficient. Therefore, continuing to explore the risk factors of MCI, especially the influence of physical activity on MCI and its mechanism can enrich the relevant research fields in China.

Materials and methods

For this cross-sectional study, 2,518 adults aged 60 years or older in Xinzhuang, Minhang District, Shanghai were recruited between July 2019 and April 2019, using a multistage, cluster-sampling method. A binary unconditional logistic regression model was used with MCI status as the dependent variable. Different types of physical activity were separately included in the multifactor model to test their correlations. Sensitivity analysis was performed using BADL as a stratification factor. The mediating effect of depression between physical activity and MCI was examined using the Bootstrap method.

Results

This research includes 271 (10.8%) MCI. Old age (odds ratio 2.967 [95%CI 2.063∼4.269]), having diabetes (1.816 [1.302∼2.534]), and depression (3.012 [2.209∼4.108]) were possible risk factors for MCI. High education level (0.722 [0.523∼0.999]), medium level of physical activity (0.459 [0.326∼0.645]), and high level of physical activity (0.396 [0.270∼0.580]) were possible protective factors. Medium (0.548 [0.396∼0.757]) and high levels (0.557 [0.366∼0.846]) of physical exercise and medium (0.433 [0.318∼0.590]) and high levels (0.487 [0.296∼0.801]) of household chores are possible protective factors of MCI and their significance remained in the mutually adjusted model. Sensitivity analysis showed that physical activity and household chores were possible protective factors in all strata (P < 0.05). Physical exercise and work-related activities showed a protective effect in fully independent older adults, but the effect disappeared in those who cannot be fully independent. Depression played a partially mediating role with an indirect effect of 6.67%.

Discussion

Overall, our results highlight that physical activity is a possible protective factor for MCI. Physical exercise and household chores have strong protective effects and future interventions could be targeted from this perspective. Depression plays a partially mediating role and more attention should be paid to the mental health of older adults.

Dietary Habits Modify the Association of Physical Exercise with Cognitive Impairment in Community-Dwelling Older Adults

Background: Previous studies have confirmed that both healthy diets and physical exercise have preventive effects with respect to cognitive decline with aging. The aim of this study was to investigate whether the associations of physical exercise with cognitive impairment differ in community-dwelling older adults with different dietary habits. Methods: In the 2008/2009 wave of the Chinese Longitudinal Healthy Longevity Survey, 14,966 community-dwelling older adults (≥65 years) were included for analyses. Dietary habits (including daily intake of fruits, vegetables, tea, meat, fish, eggs, food made from beans, salt-preserved vegetables, sugar, garlic, milk products, nut products, mushroom or algae, vitamins and medicinal plants) and physical exercise were assessed. Cognitive impairment was evaluated using the Chinese version of the MMSE in the 2008/2009 and 2011/2012 waves. The effect modifications of physical exercise on cognitive impairment by dietary habits were estimated using logistic regression models. Results: Older adults who practiced physical exercise exhibited a trend of decreased probability of cognitive impairment at baseline and follow-up (OR = 0.92, 95% CI = 0.80–1.06, p = 0.273; OR = 0.83, 95% CI = 0.65–1.05, p = 0.123, respectively) compared with those who did not practice physical exercise. When stratified by dietary habits, physical exercise had a protective effect with respect to prevalent cognitive impairment in older adults who ate fruits (OR = 0.74, 95% CI = 0.58–0.94, p = 0.016), ate food made from beans (OR = 0.76, 95% CI = 0.62–0.93, p = 0.007), did not eat sugar (OR = 0.81, 95% CI = 0.68–0.98, p = 0.028) and ate milk products (OR = 0.75, 95% CI = 0.57–0.97, p = 0.030); in the longitudinal analyses, physical exercise had a protective effect with respect to incident cognitive impairment in older adults who ate fruits (OR = 0.63, 95% CI = 0.41–0.98, p = 0.040) and milk products (OR = 0.57, 95% CI = 0.35–0.94, p = 0.027). Fruits, food made from beans and milk products modified the associations of physical exercise with prevalent cognitive impairment (p values for interaction = 0.008, 0.005 and 0.082, respectively). Conclusions: The associations of physical exercise with cognitive impairment could be modified by certain dietary habits. Physical exercise was not found to be significantly protective with respect to cognitive impairment in older adults unless they had specific dietary habits. Thus, dietary habits should be emphasized when investigating the beneficial effects of physical exercise on cognitive function in community-dwelling older adults.

Selenium Intake and its Interaction with Iron Intake Are Associated with Cognitive Functions in Chinese Adults: A Longitudinal Study

Studies on the relation between selenium intake and cognitive function are inconclusive. This study aimed to examine the associations between dietary selenium intake and cognitive function among Chinese adults and tested the interaction effect of selenium intake and iron intake on cognition. Data from 4852 adults aged 55 years and above who attended the 1991–2006 China Health and Nutrition Survey (CHNS) were used. Cognitive function was assessed through face-to-face interviews in 1997, 2000, 2004, and 2006. A 3-day, 24-hour recall was used to collect dietary selenium intake. Multivariable mixed linear regression and logistic regression were used in the analyses. In fully adjusted regression models, the regression coefficients (95% confidence interval) were 0.00, 0.29 (−0.12–0.70), 0.26 (−0.18–0.70), and 0.50 (0.02–0.97) across the quartiles of selenium intake. In the subgroup analysis, the positive association between selenium intake and cognitive function was only observed in the participants who live in the southern region but not those in the northern region. The selenium-intake-to-iron-intake ratio was inversely associated with low global cognition scores. Furthermore, only those with a normal BMI had a positive association between selenium and cognition. In conclusion, high selenium intake was linked to better cognitive function and a lower risk of cognition decline in Chinese adults among those with low iron intake. A substantial interaction was found between selenium intake and BMI or region.

The Effects of Brain Magnetic Resonance Imaging Indices in the Association of Olfactory Identification and Cognition in Chinese Older Adults

Background

Olfactory identification dysfunction frequently occurs in individuals with cognitive decline; however, a pathological mechanism linking the two has not been discovered. We aimed to study the association between olfactory identification and cognitive function, and determine the effects of brain regions atrophy therein.

Methods

A total of 645 individuals (57.5% were female) from the Taizhou Imaging Study, who underwent cognitive and olfactory identification measurements, were included. A subsample of participants underwent brain magnetic resonance imaging (n = 622). Cognition was assessed with a neuropsychological battery. Olfactory identification was measured using a 12-item Sniffin’ Sticks test. Beta and logistic regressions were used to elucidate the association between olfactory identification and cognition, and the effects of brain regions atrophy in this association.

Results

Dementia was diagnosed in 41 (6.4%) individuals (mean age = 64.8 years), and mild cognitive impairment (MCI) in 157 (24.3%) individuals (mean age = 64.4 years). Olfactory identification was associated with MMSE and MoCA (both P < 0.001) and specific cognitive domains (memory, executive function, visuospatial function, and language; all P < 0.05). Higher olfactory identification was associated with lower likelihood of MCI and dementia (P < 0.05). The amygdala volume was significantly related to olfactory identification, MMSE, MoCA, and language, and could attenuate the association between olfactory identification and cognitive function.

Conclusion

The association between olfactory identification and cognition can be partly attributable to differences in amygdala volume, suggesting that the amygdala could be a shared neural substrate that links olfactory identification and cognitive function. Limitations of this study include that all these results were based on a cross-sectional study.

COVID-19 associated cognitive impairment: A systematic review

INTRODUCTION

COVID-19 has a wide range of clinical manifestations. Neurological manifestations in COVID-19 patients were demonstrated during the pandemic, including cognitive impairment. This study aimed to determine any relationship between COVID-19 and cognitive complaints, such as dementia, mild cognitive impairment (MCI), or subjective cognitive decline (SCD).

METHODS

We performed a systematic review of MEDLINE via Ebsco, Cochrane EMBASE, SCOPUS, and LILACS electronic databases of observational studies with COVID-19 patients confirmed by serology or PCR who developed new cognitive impairment or deteriorated from previous cognitive impairment after infection. This review protocol was recorded on PROSPERO with registration number CRD 42021241590.

RESULTS

A total of 3.520 articles were retrieved and read. Twenty-two studies were selected for our review. A wide range of cognitive assessment tools (n = 25) was used. The most described affected domains in these studies were executive functions, attention, and episodic memory. Thirteen studies showed a pattern of cognitive impairment in processing speed, inattention, or executive dysfunction assessed through working memory.

CONCLUSION

This review highlights the high frequency of cognitive impairment after COVID-19 infection. However, we were unable to differentiate whether the cognitive impairment found corresponded to mild cognitive impairment or dementia through data from selected studies, and this issue serves as one objective of future studies to be addressed on this topic.

Blood copper excess is associated with mild cognitive impairment in elderly Chinese

BACKGROUND

Copper is associated with mild cognitive impairment (MCI). However, there is a lack of relevant population studies with large sample sizes.

AIMS

This study used baseline data from a cohort study to determine the distribution characteristics of MCI in the elderly and to estimate the association between whole blood copper concentrations and MCI.

METHODS

MCI status was screened by the Mini-Mental State Examination (MMSE) scale and Activities of Daily Living (ADL) scale. The concentration of copper in whole blood was determined by Inductively Coupled Plasma Mass Spectrometer (ICP-MS).

RESULTS

A total of 1057 subjects with an average age of 71.82 ± 6.45 years were included in this study. There were 215 patients with MCI, and the prevalence of MCI was 20.34%. After adjusting for general demographic variables, logistic regression analysis showed that the risk of MCI in the elderly with high copper level was 1.354 times higher than that in the elderly with low copper level (OR 1.354, 95% CI 1.047-1.983, P = 0.034).

CONCLUSION

In this study, it was found that the prevalence of MCI was different in gender, age, education level and other aspects, and a higher copper level in the elderly was significantly related to the occurrence of MCI. The association was stronger in older adults and men.

Normative Data for Adult Mandarin-Speaking Populations: A Systematic Review of Performance-Based Neuropsychological Instruments

OBJECTIVES

Normative data are essential for neuropsychological evaluations, but they are scarce for Mandarin-speaking populations, despite Mandarin being the language with the most native speakers. Several normative data studies have been reported in recent years for Mandarin speakers, who reside in different countries/regions (e.g., mainland China, Taiwan, and Singapore, etc.). This review aims to serve as a reference guide to appropriate norms when working with a Mandarin-speaking patient and to guide future endeavors in test validation and development in areas where studies to date fall short.

METHOD

We conducted a systematic review utilizing the PsycInfo, PubMed, and China Knowledge Resource Integrated databases as well as additional literature search through citations. We performed evaluations of the existing norms based on their test selection, cognitive domains covered, sample size, language, regions of participant recruitment, stratification by age/gender/education levels, and reporting of other psychometric properties. We focused on articles that included performance-based tests for adults but excluded those with purely clinical norms or from commercial publishers.

RESULTS

We reviewed 1155 articles found through literature search and identified 43 articles reporting normative data for this population that met our inclusion criteria. Sixty-five distinctive tests and 127 versions were covered. The results are presented within two detailed tables organized by articles and tests, respectively.

CONCLUSIONS

We discussed the strengths and limitations of these normative reports. Practitioners are recommended to utilize normative data that most closely approximate a test-taker's cultural and demographic backgrounds. Limitations of the current review are also discussed.

Decreased Vessel Density in Retinal Capillary Plexus and Thinner Ganglion Cell Complex Associated With Cognitive Impairment

Background

To determine the association of the retinal capillary plexus (RCP) and ganglion cell complex (GCC) with cognitive impairment using optical coherence tomography angiography (OCTA).

Methods

A cross-sectional, community-based study utilizing data from the participants enrolled between August 2019 and January 2020 in the Jidong Eye Cohort Study. We assessed the vessel density in RCP and GCC thickness using OCTA, and cognitive testing using the Montreal Cognitive Assessment (MoCA). Cognitive impairment in this study was defined as MoCA score &lt; 24. We used multivariable analysis to evaluate the association of RCP and GCC with cognitive impairment after adjusting for confounders.

Results

This study analyzed 1555 participants. The mean age of participants was 52.3 (8.4) years, and 861 (55.4%) were women. Cognitive impairment was observed in 268 (17.2%) participants. The adjusted odds ratio (OR) with 95% confidence interval (95% CI) for parafovea vessel density in the deep RCP with cognitive impairment was 1.20 (1.03–1.39). For vessel area and length density surrounding foveal avascular zone with cognitive impairment, the ORs with 95% CIs were 1.23 (1.07–1.41) and 1.30 (1.13–1.49), respectively. For thickness in the superior GCC with cognitive impairment, the OR with 95% CI was 1.16 (1.01–1.32).

Conclusion

Lower vessel density in the RCP and thinner GCC were associated with cognitive impairment. Our results suggest that alterations in the RCP and GCC could provide further evidence when assessing the cognitive function and may even be potentially useful biomarkers in the detection of cognitive impairment.

Association of waist-calf circumference ratio with incident cognitive impairment in older adults

BACKGROUND

The longitudinal relation of central fat and muscle mass with cognitive function remains unclear.

OBJECTIVES

We aimed to evaluate the relation of anthropometric measures, including BMI, waist circumference (WC), calf circumference (CC), and waist-calf circumference ratio (WCR), with incident cognitive impairment in older adults.

METHODS

A total of 3312 participants aged ≥65 y (mean: 81.8 y) who were free of cognitive impairment [the Chinese version of the Mini-Mental State Examination (MMSE) scores ≥24 points] in the Chinese Longitudinal Healthy Longevity Survey were included. The primary outcome was incident cognitive impairment, defined as MMSE scores <24 points at the exit visit. Secondary outcomes were incident cognitive decline, defined as a reduction of MMSE scores ≥3 points at the exit visit, and incident decline in different cognitive domains, defined as a reduction of MMSE scores in the domain ≥15% at the exit visit.

RESULTS

During a median follow-up duration of 3.6 y, 565 (17.1%) participants developed incident cognitive impairment. Overall, with mutual adjustments, higher WC [≥89 cm (fourth quartile) compared with <75 cm (first quartile); adjusted HR: 1.56; 95% CI: 1.19, 2.04] and higher WCR [≥2.9 (fourth quartile) compared with <2.4 (first quartile); adjusted HR: 1.96; 95% CI: 1.52, 2.52] were significantly associated with a higher risk of cognitive impairment, and higher CC [≥34 cm (fourth quartile) compared with <28 cm (first quartile); adjusted HR: 0.44; 95% CI: 0.33, 0.59] was associated with a lower hazard of cognitive impairment. Similar results were found for the secondary outcomes. However, BMI was not significantly associated with the study outcomes.

CONCLUSIONS

High WC and low CC were significantly associated with higher incident cognitive impairment in older adults. Moreover, WCR had a relatively stronger association with cognitive impairment compared with each circumference, suggesting maintaining both higher lean mass and lower central fat in older adults for the prevention of cognitive impairment.

The Incidence and Burden of Risk Factors for Mild Cognitive Impairment in Older Rural Chinese Persons

Objective: The study investigated the prevalence of mild cognitive impairment (MCI), a common cognitive disorder in late life, among rural older residents in China. The associated risk factors were also analyzed. Methods: Two thousand one hundred forty-six older adults aged 60 or more in a rural town of Zhejiang Province, China, were recruited and analyzed. Demographic characteristics were collected by a self-designed questionnaire. Diagnosis of MCI was made by well-trained primary care physicians according to the Petersen criteria. Results: 23.16% of the analyzed sample were diagnosed with MCI, while the prevalence was significantly higher in women, those never married, not employed, and with older age, lower education, diabetes, coronary heart disease and stroke. Stepwise logistic regression indicated that age, education, diabetes, coronary heart disease, and stroke were significant predictive factors of MCI. Conclusion: The prevalence of MCI in rural older residents in China is high, and those with specific demographic characteristics like women, never married, not employed, and with older age, lower education and chronic physical conditions should be more concerned in primary care management. Integrated care approaches managing MCI and comorbid chronic conditions are recommended in future management practices.

Earlier migration, better cognition? The role of urbanization in bridging the urban-rural cognition gaps in middle and older age

OBJECTIVES

With the process of population aging and urbanization, a vast amount of studies have confirmed the increasing urban-rural cognition gaps, while less is known about the extent to which cognition gaps can be explained by urban-rural difference and urbanization status. This study aimed to examine the role of urbanization in bridging the cognition gaps for Chinese middle-aged and older adults.

METHOD

Based on the national representative China Health and Retirement Longitudinal Study (CHARLS) 2015, the Blinder-Oaxaca decomposition method was employed. The method uses stratified linear regression to disaggregate cognition gaps into explained and unexplained differences, as well as the absolute and relative attribution of explanatory factors.

RESULTS

There were significant cognitive differences between urban and rural samples. Migrating to the urban predicts better cognition among the rural-born. A larger environment-related explained gap existed for those fully urbanized and those migrating earlier, indicating that migration can operate through a beneficial and cumulative change in the environment and bridge the urban-rural cognition gap.

CONCLUSION

Public health actions targeting cognitive disparities can benefit from focusing on the unequal distribution in urban-rural social and economic recourses. Areas of priority include promoting their socioeconomic status, physical functioning, social support, and lifestyles.

Enhancement of Aging in Place: An Evolving Understanding of Person-Centered Dementia Care in Home Settings

BACKGROUND

There has been a rich body of literature on informal caregivers of persons with dementia (PWD). However, little has been discussed on how to facilitate person-centered dementia care in home settings with spouses as primary caregivers. We tend to take it for granted that spouses provide person-centered care for PWD. However, being spouses of PWD and living with them for several decades does not necessarily mean that it is easier for them to provide person-centered dementia care and maintain valued and healthy relationships.

OBJECTIVE

The current study aimed to explore dyadic experiences of PWD and their spousal caregivers and develop a culturally and contextually-sensitive understanding of person-centered dementia care in home-based settings.

METHODS

A total of 20 dyads of PWD and their care partners were selected for this study. A trained qualitative interviewer conducted a one-on-one interview with each participant with dementia and their care partners separately. We adopted both conventional and directed content analyses.

RESULTS

Our findings provide examples of care partners provide person-centered care, resulting in a profound positive impact on their wellbeing. Adaptive leadership and collaborative work emerged as a key finding in facilitating person-centered dementia care. Cultural relevancy of person-centered dementia care was also interpreted from the data. The study findings provide implications for the evolving of person-centered dementia care model in home-based settings.

CONCLUSION

Findings from this study highlight the significance of facilitating person-centered dementia care in home-based settings between PWD and their primary family caregivers.

The Relationship Between Low-Density Lipoprotein Cholesterol and Progression of Mild Cognitive Impairment: The Influence of rs6859 in PVRL2

Background: Genome-wide association studies have identified many Alzheimer's disease (AD) genetic-risk single nucleotide polymorphisms (SNPs) and indicated the important role of the cholesterol/lipid metabolism pathway in AD pathogenesis. This study aims to investigate the effects of cholesterol and genetic risk factors on progression of mild cognitive impairment (MCI) to AD. Methods: We prospectively followed 316 MCI participants aged ≥50 years with a baseline cholesterol profile and SNP genotyping data for 4.5 years on average in a sub-cohort of the Shanghai Aging Study. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol in serum were measured at baseline. SNP genotyping was performed using a MassARRAY system. At follow-up, consensus diagnosis of incident dementia and AD were established based on medical, neurological, and neuropsychological examinations. Cox regression models were used to assess the association of cholesterol and SNP with incident AD. Results: The AG/AA genotypes of PVRL2 rs6859 were significantly associated with increased incident AD in MCI participants, compared with GG genotype (adjusted hazard ratio [HR] 2.75, 95% confidence interval [CI] 1.32-5.76, p = .007, false discovery rate-adjusted p = .030). In PVRL2 rs6859 AG/AA carriers, each-1 mmol/L higher level of LDL-C was significantly associated with a 48% decreased risk of AD (adjusted HR 0.52, 95%CI 0.33-0.84, p = .007). Consistent results were obtained when using LDL-C as the categorical variable (P for trend = 0.016). Conclusion: The relationship between LDL-C and progression of MCI may be influenced by genetic variants.

Dietary Patterns Are Associated With Multi-Dimensional Cognitive Functions Among Adults Aged 55 and Older in China

Background

The intake of certain food and nutrients may play a crucial role in cognitive health. However, research on the relationship between dietary patterns and cognitive function is limited. This study aims to investigate the associations between dietary patterns and multi-dimensional cognitive functions, such as global cognitive status and related domain profiles, mild cognitive impairment (MCI), and four major subtypes of Chinese adults.

Methods

Using the baseline data from the Community-based Cohort Study on Nervous System Diseases (2018–2019), we selected 4,309 Chinese adults aged 55 years and older as subjects with complete diet, cognition, and other related data. We collected food data for the past 12 months with a valid semi-quantitative food frequency questionnaire. Diving 49 food items into 13 subgroups, we used factor analysis to derive the main dietary patterns. We evaluated cognitive functions based on the scores of the Montreal Cognitive Assessment (MoCA) and used quantile regression and multivariable logistic regression to examine the relationship between dietary patterns and cognitive-related outcomes.

Results

We identified four dietary patterns, explaining 50.11% of the total variance: “meat-preferred” pattern, “plant-preferred” pattern, “eggs- and dairy-preferred” pattern, and “grain-preferred” pattern. After adjusting for all potential confounders, the “meat-preferred” pattern and the “plant-preferred” pattern were associated with higher scores of global cognition and several cognitive domains (p &lt;0.05), while the “grain-preferred” pattern was associated with lower scores of global cognition (β = −0.36, p &lt;0.05), execution (β = −0.19, p &lt;0.05), visuospatial (β = −0.09, p &lt;0.05), and language (β = −0.05, p &lt;0.05). Adults adhering to the “meat-preferred” pattern and the “plant-preferred” pattern had decreased odds of MCI and some MCI subtypes (p-trend &lt;0.05); in contrast, those in the top quartiles of the “grain-preferred” pattern had increased odds of MCI [adjusted odds ratio (AOR) = 1.34, 95% CI: 1.11–1.63, p-trend = 0.003].

Conclusions

Adhering to the “plant-preferred” pattern and the “meat-preferred” pattern may help improve the multi-dimensional cognitive functions; on the contrary, adhering to the “grain-preferred” pattern may worse cognitive health. More prospective studies in this field are needed to strengthen the evidence.

Association Between Body Mass Index and Incident Dementia Among Community-Dwelling Older Adults: The Shanghai Aging Study

BACKGROUND

The relationship between body mass index (BMI) and dementia is inconclusive. Undesirable loss of fat-free mass is a risk factor for cognitive decline while obesity is also a risk factor for cardio-metabolic disorders among the older adults.

OBJECTIVE

This study aimed to examine the association between BMI and incident all-cause dementia among Chinese older adults using a prospective study.

METHODS

Participants were 1,627 community residents aged 60 or older without dementia from the Shanghai Aging Study. Cox regression models, incorporated with restricted cubic splines, were used to explore a nonlinear association between baseline BMI and risk of all-cause dementia as measured by hazard ratio (HR) using both frequentist and Bayesian approach.

RESULTS

We diagnosed 136 incident dementia cases during the mean follow-up of 5.3 years. Compared with moderate BMI (18.5-24.0 kg/m2), low BMI (<  18.5 kg/m2) were related to an increased risk of dementia with the HR as 3.38 (95% CI 1.50-7.63), while high BMI (≥24.0 kg/m2) showed a decreased risk of dementia without statistical significance (HR = 0.91, 95% CI 0.60 to 1.39). Sensitivity analysis in participants without central obesity indicated that the association was still significant with even higher HR. Bayesian approach presented the similar results.

CONCLUSION

Our result indicates that low BMI may contribute to high risk of incident dementia, even in individuals without central obesity.

Genetic Effects of NDUFAF6 rs6982393 and APOE on Alzheimer’s Disease in Chinese Rural Elderly: A Cross-Sectional Population-Based Study

Purpose

To investigate the associations of genotypes of NDUFAF6 rs6982393 and APOE and their combined genotypes with the risk of Alzheimer’s disease (AD) and mild cognitive impairment (MCI) in Chinese rural elderly.

Methods

This cross-sectional population-based study included 5096 older adults (age ≥60 years, 57.1% female). Genotypes of NDUFAF6 rs6982393 and APOE were detected using the multiple-polymerase chain reaction amplification. We diagnosed AD following the criteria of Diagnostic and Statistical Manual of Mental Disorders, the fourth edition and diagnosed MCI following the Petersen’s criteria MCI. Data were analyzed using the logistic regression model.

Results

The overall prevalence of AD and MCI was 3.57% (95% confidence interval [CI]: 0.040, 0.053) and 22.65% (95% CI: 0.223, 0.247), separately. The TT versus CC/CT genotype of NDUFAF6 rs6982393 was related to a higher risk of AD with the multi-adjusted odds ratio (95% CI) being 1.61 (1.02, 2.54) in the total sample, 3.36 (1.48, 7.60) in those aged 60–69, and 1.24 (0.71, 2.17) in those aged 70 years and above. The interaction between genotype of NDUFAF6 rs6982393 with age groups (60–69 versus ≥70 years) was significant on the risk of AD. The presence of APOE ε4 was not significantly associated with the risk of AD. Carrying both NDUFAF6 TT and APOE ε4 was related to a higher risk of AD with the multi-adjusted odds ratio (95% CI) being 2.69 (1.10, 2.56). In addition, there was no significant association between the above genotypes and MCI.

Conclusion

In Chinese rural elderly, the TT versus CT/CC genotype of NDUFAF6 rs6982393 was associated with an increased likelihood of AD; such an association only existed among young-old adults. Carrying both NDUFAF6 rs6982393-TT and APOE ε4 was related to a higher risk of AD. This finding highlights the importance of considering age and combined genotype in studying the genetic profiles of AD.

Impact of Internet Use on Cognitive Decline in Middle-Aged and Older Adults in China: Longitudinal Observational Study

Background

Given that cognitive decline lacks effective treatment options and has severe implications for healthy aging, internet use may achieve nonpharmacological relief of cognitive decline through cognitive stimulation and social engagement.

Objective

This longitudinal study aimed to investigate the relationship between the diversity, frequency, and type of internet use and cognitive decline, and to provide theoretical support and suggestions for mitigating cognitive decline in middle-aged and older adults.

Methods

Data were obtained from a total of 10,532 survey respondents from the China Family Panel Studies database from wave 3 (2014) and wave 5 (2018) of the survey. Cognitive function was measured using vocabulary tests, and internet use was categorized into five aspects: study, work, socializing, entertainment, and commercial-related activities. Associations between the diversity, frequency, and type of internet use and cognitive decline were estimated by controlling for demographic variables and health status risk factors through fixed-effects models.

Results

After controlling for demographic and health status risk factors, the type and frequency of internet use were found to be associated with cognitive functioning during the subsequent 4-year period, and different types of internet use had different effects on cognitive decline. Frequency of internet use of at least once a week for study (β=0.620, 95% CI 0.061 to 1.180; P=.04), work (β=0.896, 95% CI 0.271 to 1.520; P=.01), and entertainment (β=0.385, 95% CI –0.008 to 0.778; P=.06), as well as less than once a week for social purposes (β=0.860, 95% CI 0.074 to 1.650; P=.06), were associated with better cognitive function. Frequency of internet use of less than once a week for commercial-related activities (β=–0.906, 95% CI –1.480 to –0.337; P=.005) was associated with poorer cognitive function. Using the internet for more than one type of activity (β=0.458, 95% CI 0.065 to 0.850; P=.03) and at least once a week (β=0.436, 95% CI 0.066 to 0.806; P=.02) was associated with better cognitive function.

Conclusions

This study shows that breadth and depth of internet use are positively associated with cognitive function and that different types of internet use have different roles in cognitive decline. The importance of the internet as a nonpharmacological intervention pathway for cognitive decline is emphasized. Future research could explore specific mechanisms of influence.