Association of cognitive impairment and grip strength trajectories with mortality among middle-aged and elderly adults

Prevalence of mild cognitive impairment and modifiable risk factors: A cross-sectional study in rural older adults with diabetes

To determine the prevalence and modifiable risk factors for MCI in older adults with T2DM in rural China. This cross-sectional study encompassed 96 villages, employing a cluster sampling approach to recruit eligible older adults with T2DM as study participants. Logistic regression analysis was utilized to identify modifiable risk factors associated with MCI. Average marginal effects were calculated. The discriminatory performance of these risk factors in identifying MCI was evaluated by plotting the receiver operating curve and calculating the value of the area under the curve. A total of 898 older adults with T2DM in our study. The overall prevalence of MCI was 50.22 %. Independent associations with MCI were found in poor self-management ability of diabetes (OR = 0.808, 95 % CI: 0.808, 0.766), depressive symptoms (OR = 3.500, 95 % CI: 1.933, 6.337), moderate (OR = 0.936, 95 % CI: 0.017, 0.075) and high (OR = 0.939, 95 % CI: 0.016, 0.100) levels of physical activity, poorer oral health (OR = 2.660, 95 % CI: 2.226, 3.179), and lower grip strength (OR = 0.913, 95 % CI: 0.870, 0.958). The AUC was 0.967 (95 % CI 0.508-0.470). The prevalence of MCI was high among older adults with T2DM in rural areas of China. The self-management ability of diabetes, depressive symptoms, physical activity, oral health and grip strength were modifiable risk factors of MCI. Targeted interventions should be developed and implemented to address these modifiable risk factors, aiming to enhance cognitive function and mitigate the incidence of MCI in older adults with T2DM.

Cognitive trajectories in older adults and the role of depressive symptoms: A 7-year follow-up study

OBJECTIVES

To examine different trajectories of cognitive changes in elderly adults and explore the mediating role of depressive symptoms.

DESIGN

A 7-year, community-based, prospective cohort study.

SETTING

The downtown neighborhood of Shanghai, China.

PARTICIPANTS

A cohort of 394 older adults, with an average age of 71.8 years, was recruited in 2015 and has been reassessed every two years until 2021.

METHODS

Latent Class Growth Analysis was used to model aging trajectories and Linear Mixed-Effect Models for Repeated Measures were used to estimate the least squares mean changes of cognition between subjects with depression (DEP+) and without (DEP-) across all visits.

RESULTS

Three cognitive trajectories were identified: the "successful aging" (SA) trajectory had the best and most consistent performance (n=229, 55.9%); the "normal aging" (NA) trajectory showed lower but stable cognition (n=141, 37.3%); while the "cognitive decline" (CD) trajectory displayed poor and declining cognition (n=24, 6.8%). Depressive symptoms were found to be influential across all trajectories. In the CD trajectory, the MoCA scores of the DEP+ group increased in within-group comparisons and were significantly higher than those of the DEP- group at visits 1 and 3 in between-group comparisons. A similar trend was observed in the NA trajectory, though it did not reach statistical significance.

CONCLUSIONS

Our research suggests that mild and decreasing depressive symptoms can be a reversible factor that might slow down the irreversible cognitive decline in the elderly. Therefore, we suggest that even mild depressive symptoms in the elderly should be monitored and detected.

Association between grip strength and cognitive impairment in older American adults

BACKGROUND AND AIMS

Exponential population aging has led to an increased prevalence of cognitive impairment worldwide. Hand grip strength, which may be associated with physical activity, could be a useful predictor of cognitive impairment. However, few studies have reported the association, if any, between hand grip strength and cognitive function.

METHODS

We used data obtained from the National Health and Nutrition Examination Survey between 2011-2012 and 2013-2014 to investigate the association between hand grip strength and cognitive impairment. Cognitive impairment was assessed using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), animal fluency (AF), and digit symbol substitution test (DSST) scores. Cutoff values of CERAD < 5, AF < 14, and DSST < 34 were used to define cognitive impairment. In this cross-sectional study, we used odds ratios to determine the potential usefulness of hand grip strength for the prediction of cognitive impairment.

RESULTS

This study included 2,623 participants aged ≥60 years. The DSST results showed that hand grip strength was associated with a low risk of cognitive impairment and that subgroup analysis showed that male sex, 60-69 years of age, and the Non-Hispanic (NH)-White, NH Black, and Asian were associated with a significantly low risk of cognitive impairment. The CERAD test results showed that 70-79 years of age and the NH White were significantly associated with a low risk of cognitive impairment. By following full adjustment, we did not observe statistically significant differences between hand grip strength and cognitive impairment based on the CERAD test. The AF test results showed that >80 years of age, female sex, and the NH White were associated with a significantly low risk of cognitive impairment. The most important finding is that a linear association lies between grip strength and cognitive impairment, as well as a sex-based linear association. Machine learning of the XGBoost model suggests that grip strength is one of the top two most important negative predictor variables.

CONCLUSION

We observed an inverse relationship between hand grip strength and cognitive impairment, which might suggest a shared underlying mechanism that needs to be further investigated using a large-scale prospective clinical trial to validate our findings.

The association between cognitive impairment and 30-day mortality among older Chinese inpatients

Purpose

Although the association between cognitive impairment and mortality has been widely described among community-dwelling older adults, this association in hospitalized patients was limited.

Objectives

This study's purpose was to explore the association between cognitive impairment and 30-day mortality after adjustment of factors among Chinese in-patients.

Methods

This was a large-scale prospective study based on a cohort of patients aged 65 years and older, whose cognitive function was assessed using the Mini-Cog instrument, followed up at 30-days for mortality. Multivariate logistic regression models were used to assess the association between cognitive impairment and 30-day mortality.

Results

There were 9,194 inpatients in our study, with an average age of 72.41 ± 5.72. The prevalence of cognitive impairment using the Mini-Cog instrument was 20.5%. Multivariable analyses showed that patients with cognitive impairment have an increased risk of 30-day mortality, compared to those with normal cognitive function (OR = 2.83,95%CI:1.89–4.24) in an unadjusted model. In the fully adjusted model, Patients with cognitive impairment had an increased risk of 30-day mortality compared to those with normal cognitive function in the completely adjusted model (OR = 1.76,95% CI: 1.14–2.73). Additionally, this association still existed and was robust after performing a stratified analysis of age, gender, frailty and depression, with no significant interaction (P > 0.05).

Conclusions

Our study found that older Chinese in-patients with cognitive impairment have a 1.76-fold risk of 30-day mortality compared to patients with normal cognitive function, suggesting that clinicians and nurses need to early implement cognitive function screening and corresponding interventions to improve clinical outcomes for older in-patients.

Cognitive Trajectories in Community-Dwelling Older Adults and Incident Dementia, Disability and Death: A 10-Year Longitudinal Study

Objective

The inter-individual variability in cognitive changes may be early indicators of major health events. We aimed to determine whether late-life cognitive trajectories were associated with incident dementia, persistent physical disability and all-cause mortality.

Methods

Data came from a cohort of older community-dwelling individuals aged 70 years or above in Australia and the United States. Global cognition, verbal fluency, episodic memory and psychomotor speed were assessed regularly at up to seven waves between 2010 and 2017. Dementia, disability in activities of daily living, and death were adjudicated between 2017 and 2020. Latent classes of cognitive trajectories over seven years were determined using group-based trajectory modeling. Multivariable logistic regression was used for the prospective associations between cognitive trajectories and these outcomes.

Results

Cognitive trajectories were defined for 16,174 participants (mean age: 78.9 years; 56.7% female) who were alive and without incident dementia or disability by 2017, among which 14,655 participants were included in the association analysis. Between three and five trajectory classes were identified depending on the cognitive test. Cognitive trajectories were strongly associated with the risk of dementia. For example, compared to those in the highest-functioning trajectory, the worst performers of episodic memory had a 37-fold increased risk of dementia (95% CI: 17.23–82.64). The lowest trajectories of both global cognition and episodic memory also predicted increased mortality risk (OR: 1.80, 95% CI: 1.28–2.52; OR: 1.61, 95% CI: 1.09–2.36, respectively), while only slow psychomotor speed was marginally associated with physical disability (OR: 2.39, 95% CI: 0.99–5.77).

Conclusions

In older individuals, cognitive trajectories appear to be early indicators of clinically relevant health outcomes. Systematic cognitive assessments as part of routine geriatric evaluation may facilitate early identification and interventions for those individuals at highest risk.

Distinct Cognitive Trajectories in Late Life and Associated Predictors and Outcomes: A Systematic Review

Background

Cognitive aging is a dynamic process in late life with significant heterogeneity across individuals.

Objective

To review the evidence for latent classes of cognitive trajectories and to identify the associated predictors and outcomes.

Methods

A systematic search was performed in MEDLINE and EMBASE for articles that identified two or more cognitive trajectories in adults. The study was conducted following the PRISMA statement.

Results

Thirty-seven studies were included, ranging from 219 to 9,704 participants, with a mean age of 60 to 93.4 years. Most studies (n = 30) identified distinct cognitive trajectories using latent class growth analysis. The trajectory profile commonly consisted of three to four classes with progressively decreasing baseline and increasing rate of decline-a 'stable-high' class characterized as maintenance of cognitive function at high level, a 'minor-decline' class or 'stable-medium' class that declines gradually over time, and a 'rapid-decline' class with the steepest downward slope. Generally, membership of better classes was predicted by younger age, being female, more years of education, better health, healthier lifestyle, higher social engagement and lack of genetic risk variants. Some factors (e.g., education) were found to be associated with cognitive function over time only within individual classes.

Conclusion

Cognitive aging in late life is a dynamic process with significant inter-individual variability. However, it remains unclear whether similar patterns of cognitive aging are observed across all cognitive domains. Further research into unique factors which promote the maintenance of high-cognitive function is needed to help inform public policy.