Vascular Health and Genetic Risk Affect Mild Cognitive Impairment Status and 4-Year Stability: Evidence From the Victoria Longitudinal Study

Association of Unhealthy Lifestyle and Genetic Risk Factors With Mild Cognitive Impairment in Chinese Older Adults

Importance

Apolipoprotein E polymorphism ε4 (APOE ε4) and methylenetetrahydrofolate reductase (MTHFR) TT genotype are genetic risk factors of mild cognitive impairment (MCI), but whether this risk can be changed by modifiable lifestyle factors is unknown.

Objective

To explore whether unhealthy lifestyle (unhealthy dietary intake, current smoking, nonlimited alcohol consumption, and irregular physical activities) is associated with a higher risk of age-related MCI considering genetic risk.

Design, Setting, and Participants

This population-based cohort study used data from Tianjin Elderly Nutrition and Cognition (TENC) study participants, recruited from March 1, 2018, through June 30, 2021, and followed up until November 30, 2022. Participants were Chinese adults aged 60 years or older who completed the neuropsychological assessments, general physical examinations, and a personal interview.

Exposures

Healthy lifestyle was defined according to the Chinese Dietary Guidelines 2022, including healthy diet, regular physical activity, limited alcohol consumption, and no current smoking, categorized into healthy and unhealthy lifestyles according to weighted standardized lifestyle score. Genetic risk was defined by MTHFR TT genotype and APOE ε4, categorized into low and high genetic risk according to weighted standardized genetic risk score.

Main Outcomes and Measures

The main outcome was newly diagnosed MCI as identified using a modified version of Petersen criteria. Hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazard regression models.

Results

A total of 4665 participants were included (mean [SD] age, 67.9 [4.9] years; 2546 female [54.6%] and 2119 male [45.4%]); 653 participants with new-onset MCI (mean [SD] age, 68.4 [5.4] years; 267 female [40.9%] and 386 male [59.1%]) were identified after a median follow-up of 3.11 years (range, 0.82-4.61 years). Individuals with a low genetic risk and an unhealthy lifestyle (HR, 3.01; 95% CI, 2.38-3.79), a high genetic risk and a healthy lifestyle (HR, 2.65; 95% CI, 2.03-3.44), and a high genetic risk and an unhealthy lifestyle (HR, 3.58; 95% CI, 2.73-4.69) had a higher risk of MCI compared with participants with a low genetic risk and a healthy lifestyle. There was a synergistic interaction between lifestyle categories and genetic risk (β = 3.58; 95% CI, 2.73-4.69).

Conclusions and Relevance

In this cohort study of TENC participants, the findings show that unhealthy lifestyle and high genetic risk were significantly associated with a higher risk of MCI among Chinese older adults. Unhealthy lifestyle factors were associated with a higher risk of MCI regardless of genetic risk, and lifestyle and genetic risk had synergistic interactions. These findings could contribute to the development of dietary guidelines and the prevention of early-stage dementia.

Personality associations with lung function and dyspnea: Evidence from six studies

OBJECTIVE

The present study examined the association between Five Factor Model personality traits and lung function and dyspnea.

METHODS

Participants were middle aged and older adults aged 34-103 years old (N > 25,000) from the Midlife in the United States Study (MIDUS), the Health and Retirement Study (HRS), the English Longitudinal Study of Ageing (ELSA), the National Health and Aging Trends Survey (NHATS), and the Wisconsin Longitudinal Study graduate (WLSG) and sibling (WLSS) samples. Data on peak expiratory flow (PEF), dyspnea, personality traits, smoking, physical activity, body mass index (BMI), emotional/psychiatric problems, and demographic factors were obtained in each sample.

RESULTS

A meta-analysis indicated that higher neuroticism was related to lower PEF, higher risk of PEF less than 80% of predicted value, and higher risk of dyspnea. In contrast, higher extraversion and conscientiousness were associated with higher PEF, lower likelihood of PEF lower than 80% of the predicted value, and lower risk of dyspnea. Higher openness was related to higher PEF and lower risk of PEF less than 80%, whereas agreeableness was related to higher PEF and lower risk of dyspnea. Smoking, physical activity, BMI and emotional/psychiatric problems partially accounted for these associations. There was little evidence that lung disease moderated the association between personality and PEF and dyspnea.

CONCLUSIONS

Across cohorts, this study found replicable evidence that personality is associated with lung function and associated symptomatology.

Using multivariate base rates of low scores to understand early cognitive declines on the uniform data set 3.0 Neuropsychological Battery

OBJECTIVE

Low neuropsychological test scores are commonly observed even in cognitively healthy older adults. For batteries designed to assess for and track cognitive decline in older adults, documenting the multivariate base rates (MBRs) of low scores is important to differentiate expected from abnormal low score patterns. Additionally, it is important for our understanding of mild cognitive impairment and preclinical declines to and determine how such score patterns predict future clinical states.

METHOD

The current study utilized Uniform Data Set Neuropsychological Battery 3.0 (UDS3NB) data for 5,870 English-speaking, older adult participants from the National Alzheimer's Coordinating Center from 39 Alzheimer's disease Research Centers from March 2015 to December 2018. MBRs of low scores were identified for 2,608 cognitively healthy participants that had completed all cognitive measures. The association of abnormal MBR patterns with subsequent conversion to mild cognitive impairment and dementia were explored.

RESULTS

Depending on the operationalization of "low" score, the MBR of demographically adjusted scores ranged from 1.40 to 79.2%. Posttest probabilities using MBR methods to predict dementia status at 2-year follow up ranged from .06 to .33, while posttest probabilities for conversion to mild cognitive impairment (MCI) ranged from .12-.32.

CONCLUSIONS

The data confirm that abnormal cognitive test scores are common among cognitively normal older adults. Using MBR criteria may improve our understanding of MCI. They may also be used to enrich clinical trial selection processes through recruitment of at-risk individuals. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Targeted Nutritional Intervention for Patients with Mild Cognitive Impairment: The Cognitive impAiRmEnt Study (CARES) Trial 1

Omega-3 fatty acids (ω-3FAs), carotenoids, and vitamin E are important constituents of a healthy diet. While they are present in brain tissue, studies have shown that these key nutrients are depleted in individuals with mild cognitive impairment (MCI) in comparison to cognitively healthy individuals. Therefore, it is likely that these individuals will benefit from targeted nutritional intervention, given that poor nutrition is one of the many modifiable risk factors for MCI. Evidence to date suggests that these nutritional compounds can work independently to optimize the neurocognitive environment, primarily due to their antioxidant and anti-inflammatory properties. To date, however, no interventional studies have examined the potential synergistic effects of a combination of ω-3FAs, carotenoids and vitamin E on the cognitive function of patients with MCI. Individuals with clinically confirmed MCI consumed an ω-3FA plus carotenoid plus vitamin E formulation or placebo for 12 months. Cognitive performance was determined from tasks that assessed global cognition and episodic memory. Ω-3FAs, carotenoids, and vitamin E were measured in blood. Carotenoid concentrations were also measured in tissue (skin and retina). Individuals consuming the active intervention (n = 6; median [IQR] age 73.5 [69.5–80.5] years; 50% female) exhibited statistically significant improvements (p < 0.05, for all) in tissue carotenoid concentrations, and carotenoid and ω-3FA concentrations in blood. Trends in improvements in episodic memory and global cognition were also observed in this group. In contrast, the placebo group (n = 7; median [IQR] 72 (69.5–75.5) years; 89% female) remained unchanged or worsened for all measurements (p > 0.05). Despite a small sample size, this exploratory study is the first of its kind to identify trends in improved cognitive performance in individuals with MCI following supplementation with ω-3FAs, carotenoids, and vitamin E.

Contrasting olfaction, vision, and audition as predictors of cognitive change and impairment in non-demented older adults

OBJECTIVE

This study examines the relative utility of a particular class of noninvasive functional biomarkers-sensory functions-for detecting those at risk of cognitive decline and impairment. Three central research objectives were examined including whether (a) olfactory function, vision, and audition exhibited significant longitudinal declines in nondemented older adults; (b) multiwave change for these sensory function indicators predicted risk of mild cognitive impairment (MCI); and (c) change within persons for each sensory measure shared dynamic time-varying associations with within-person change in cognitive functioning.

METHOD

A longitudinal sample (n = 408) from the Victoria Longitudinal Study was assembled. Three cognitive status subgroups were identified: not impaired cognitively, single-assessment MCI, and multiple-assessment MCI.

RESULTS

We tested independent predictive associations, contrasting change in sensory function as predictors of cognitive decline and impairment, utilizing both linear mixed models and logistic regression analysis. Olfaction and, to a lesser extent, vision were identified as the most robust predictors of cognitive status and decline; audition showed little predictive influence.

CONCLUSIONS

These findings underscore the potential utility of deficits in olfactory function, in particular, as an early marker of age- and pathology-related cognitive decline. Functional biomarkers may represent potential candidates for use in the early stages of a multistep screening approach for detecting those at risk of cognitive impairment, as well as for targeted intervention. (PsycINFO Database Record

Factors for predicting reversion from mild cognitive impairment to normal cognition: A meta-analysis

OBJECTIVE

Subjects with mild cognitive impairment (MCI) may revert to normal cognition (NC), but predictive factors are under study. We therefore sought to identify factors which could help in predicting reversion from MCI to NC.

METHODS

Relevant studies were retrieved from PubMed, EMBASE, Cochrane Library, MEDLINE, Web of Science, EBSCO, and OVID. According to the inclusion and exclusion criteria, high-quality assessments of relevant literatures were conducted, followed by data extraction and meta-analysis with Stata 12.0 software.

RESULTS

A total of 17 studies with 6829 participants were included in the meta-analysis. The overall reversion rate is 27.57%. Positive predictive factors were found in younger age (SMD = -0.345, 95% CI, -0.501 to -0.189), higher education level (SMD = 0.337, 95% CI, 0.117-0.558), no APOE ε4 allele (OR = 0.728, 95% CI, 0.575-0.922), no hypertension (OR = 0.826, 95% CI, 0.692-0.987), no stroke (OR = 0.696, 95% CI, 0.507-0.953), and higher Mini-Mental State Examination (MMSE) score (SMD = 0.707, 95% CI, 0.461-0.953).

CONCLUSION

Individuals who are at young age, have higher education level and MMSE score, and have no APOEe4 allele, no hypertension, and no stroke had a high probability to revert from MCI to NC.

Associations of APOE ε4 With Health and Financial Literacy Among Community-Based Older Adults Without Dementia

Objectives

Older adults often exhibit low health and financial literacy, but the reasons why remain unclear. One possibility is that those older adults at high risk for developing dementia demonstrate low literacy even in the absence of marked cognitive impairment. We therefore examined associations of health and financial literacy with the APOE ε4 allele, the chief genetic risk factor for Alzheimer's disease, among older adults without dementia.

Method

Participants were 487 older adults without dementia enrolled in the Rush Memory and Aging Project (mean age = 83, mean years of education = 15, 77% female, 91% non-Hispanic White). Participants underwent APOE genotyping and assessments of cognition, health literacy, and financial literacy. Health and financial literacy scores were also averaged into a total literacy score.

Results

ε4 was associated with lower total and health literacy, with a trend toward an association with lower financial literacy, after adjustment for age, sex, and education. Associations of ε4 with lower total and health literacy persisted after further adjustment for global cognitive function and 5 specific cognitive domains.

Discussion

ε4 affects literacy even in the absence of clinical dementia and does so relatively independent of performance on traditional cognitive tests.

Physical activity correlates in people with mild cognitive impairment: findings from six low- and middle-income countries

OBJECTIVES

Despite promising research showing that physical activity (PA) might improve cognitive functioning in people with mild cognitive impairment (MCI), people with MCI are less physically active compared with the general population. Therefore, the aim of this study was to assess PA correlates among community-dwelling older people with MCI in six low- and middle-income countries.

DESIGN

Cross-sectional data from the World Health Organization's Study on Global Ageing and Adult Health were analysed.

METHODS

PA level was assessed by the Global Physical Activity Questionnaire. 4854 participants with MCI (mean age 64.4 years; 55.1% females) were grouped into those who do and do not (low PA) meet the 150 min of moderate-to-vigorous PA per week recommendation. Associations between PA and the correlates were examined using multivariable logistic regressions.

RESULTS

The prevalence of low PA was 27.4% (95% confidence interval = 25.0-30.0). In the multivariable analysis, older age and unemployment were the only sociodemographic correlates of low PA. The significant positive correlates of low PA in other domains included depression, being underweight, obesity, asthma, chronic lung disease, hearing problems, visual impairment, slow gait, weak grip strength, poor self-rated health, and lower levels of social cohesion.

CONCLUSIONS

The current data illustrate that a number of sociodemographic and health factors are associated with PA levels among older people with MCI. The promotion of social cohesion may increase the efficacy of public health initiatives while from a health care perspective, somatic co-morbidities, muscle strength and slow gait need to be considered when activating those at risk for dementia.

Personality and Lung Function in Older Adults

OBJECTIVES

Lung disease is a leading cause of disability and death among older adults. We examine whether personality traits are associated with lung function and shortness of breath (dyspnea) in a national cohort with and without chronic obstructive pulmonary disease (COPD).

METHOD

Participants (N = 12,670) from the Health and Retirement Study were tested for peak expiratory flow (PEF) and completed measures of personality, health behaviors, and a medical history.

RESULTS

High neuroticism and low extraversion, openness, agreeableness, and conscientiousness were associated with lower PEF, and higher likelihood of COPD and dyspnea. Conscientiousness had the strongest and most consistent associations, including lower risk of PEF less than 80% of the predicted value (OR = 0.67; 0.62-0.73) and dyspnea (OR = 0.52; 0.47-0.57). Although attenuated, the associations remained significant when accounting for smoking, physical activity, and chronic diseases including cardiovascular and psychiatric disorders. The associations between personality and PEF or dyspnea were similar among those with or without COPD, suggesting that psychological links to lung function are not disease dependent. In longitudinal analyses, high neuroticism (β = -0.019) and low conscientiousness (β = 0.027) predicted steeper declines in PEF.

DISCUSSION

A vulnerable personality profile is common among individuals with limited lung function and COPD, predicts shortness of breath and worsening lung function.

Olfactory evaluation in Mild Cognitive Impairment: correlation with neurocognitive performance and endothelial function

Mild Cognitive Impairment (MCI) is an intermediate condition between normal aging and dementia, associated with an increased risk of progression into the latter within months or years. Olfactory impairment, a well-known biomarker for neurodegeneration, might be present in the condition early, possibly representing a signal for future pathological onset. Our study aimed at evaluating olfactory function in MCI and healthy controls in relation to neurocognitive performance and endothelial function. A total of 85 individuals with MCI and 41 healthy controls, matched for age and gender, were recruited. Olfactory function was assessed by Sniffin' Sticks Extended Test (Burghart, Medizintechnik, GmbH, Wedel, Germany). A comprehensive neurocognitive assessment was performed. Endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery by ultrasound. MCI individuals showed an impaired olfactory function compared to controls. The overall olfactory score is able to predict MCI with a good sensitivity and specificity (70.3 and 77.4% respectively). In MCI, olfactory identification score is correlated with a number of neurocognitive abilities, including overall cognitive status, dementia rating, immediate and delayed memory, visuospatial ability and verbal fluency. FMD was reduced in MCI (2.90 ± 2.15 vs. 3.66 ± 1.96%, P = 0.016) and was positively associated with olfactory identification score (ρ_s =0.219, P = 0.025). The association remained significant after controlling for age, gender, and smoking. In conclusion, olfactory evaluation is able to discriminate between MCI and healthy individuals. Systemic vascular dysfunction might be involved, at least indirectly, in olfactory dysfunction in MCI.