The combined associations of depression and cognitive impairment with functional disability and mortality in older adults: a population-based study from the NHANES 2011-2014

Association between cognitive impairment and cardiovascular mortality in mature and older adults: A meta-analysis

BACKGROUND

Cognitive impairment contributes significantly to negative health outcomes. This meta-analysis aimed to investigate the association between cognitive impairment and cardiovascular mortality in mature and older adults.

METHODS

PubMed, Web of Science, and Embase databases were searched until February 10, 2024, to identify the association between cognitive impairment and cardiovascular mortality in mature and older adults (aged 50 years and older) from the general population. The adjusted risk estimates from the included studies were extracted and pooled using a random effects model.

RESULTS

Ten studies were included in the meta-analysis, involving 16,765 participants. The pooled hazard ratio (HR) of cardiovascular mortality was 1.75 (95 % confidence interval [CI] 1.44-2.14; I2 = 48.2 %) for individuals with cognitive impairment compared to those without, even after adjusting for common confounding factors. Subgroup analysis revealed that the prognostic value of cognitive impairment may be influenced by the assessment tools used for measuring cognition. Additionally, cognitive impairment significantly predicted cardiovascular mortality in women (HR 2.40; 95 % CI 1.54-3.74; I2 = 45.4 %) but not in men (HR 1.49; 95 % CI 0.99-2.24; I2 = 44.8 %).

CONCLUSIONS

Cognitive impairment is a significant predictor of cardiovascular mortality in mature and older adults from the general population. However, future studies are needed to evaluate the specific impact of cognitive impairment on different genders.

Exploring the role of vitamin D in cognitive function: mediation by depression with diabetes modulation in older U.S. adults, a NHANES weighted analysis

Background

The relationship between vitamin D levels, depressive symptoms, and cognitive function has yet to be definitively understood in the elderly, particularly when considering the impact of chronic diseases. This study focuses on how depression mediates the impact of 25-hydroxyvitamin D3 (25(OH)D3) on cognitive performance in older U.S. adults.

Methods

We analyzed data from 2,745 elderly individuals extracted from the NHANES 2011-2014 cycles, applying weighted processing to account for the complex multi-stage sampling design characteristic of NHANES data. Utilizing weighted data for covariate and model selection, we conducted mediation analyses on both the overall population and subgroup data. Significant mediation pathways were validated using a stratified weighted bootstrap approach. For significant subgroup pathways, we explored interactive mechanisms through interactive mediation analysis.

Results

Mediation analyses, thoroughly accounting for the impact of chronic conditions, revealed significant pathways in both the weighted overall population and the weighted diabetes subgroup. After 1,000 stratified weighted bootstrap replications, the proportion of mediation effects were 10.6% [0.040, 0.268] and 20.9% [0.075, 0.663], respectively. Interactive mediation analysis for diabetes indicated that the interaction between diabetes and depression was not significant in the direct pathway (estimates = 0.050, p = 0.113) but was significant in the mediation pathway, yielding the largest effect size compared to other covariates (estimates = 0.981, p < 0.001).

Conclusion

This study highlights the mediating role of depression in the relationship between vitamin D levels and cognitive function in the elderly, particularly emphasizing diabetes as a key moderator. Our findings suggest targeted interventions addressing both vitamin D sufficiency and depression could significantly benefit cognitive health, especially in diabetic individuals.

Associations of cognitive impairment and functional limitation with all-cause mortality risk in older adults: A population-based study from the National Health and Nutrition Examination Survey

Cognitive impairment and functional limitation are commonly observed in older adults. They have a complex correlation, and both are risk factors for mortality. This prospective cohort study aimed to explore the independent and joint impact of cognitive impairment and functional limitations on all-cause mortality in older adults. A total of 3,759 participants aged ≥ 60 years who had available information on mortality data, cognitive function, physical function, and covariates were enrolled. Cox proportional hazards regression models were employed to assess the independent and joint impacts of cognitive impairment and functional limitation on all-cause mortality. Smoothing curve fitting was used to show the nonlinear relationship between the Digit Symbol Coding (DSC) score and all-cause mortality. An interaction between cognitive impairment and functional limitation was identified when examining their associations with all-cause mortality. Cognitive impairment and functional limitation independently correlated with all-cause mortality risk even after adjusting for covariates and performing mutual adjustments (HR for cognitive impairment: 1.34, 95% CI 1.15-1.56; HR for functional limitation: 1.50, 95% CI 1.32-1.70). When the DSC score was > 18, as the score increased, the risk of death significantly decreased (HR 0.99, 95% CI 0.98-0.99). Participants with both cognitive impairment and functional limitation had the highest hazard ratio for all-cause mortality (HR 1.98, 95%CI 1.63-2.40). In summary, cognitive impairment and functional limitation independently correlated with increased all-cause mortality risk. A higher DSC score was a protective factor reducing the premature mortality risk. Older adults with cognitive impairment and functional limitation demonstrated the highest all-cause mortality risk.

Depression in persons with disabilities: a scoping review

Individuals with disabilities are more vulnerable to depression development than the general population. This study sought to map the evidence on current knowledge of depression, intervention strategies, and assessment tools among people with disabilities. This review was conducted following Arksey and O'Malley's scoping review methodology framework. An electronic search was performed on four English databases: PubMed, Cochrane Library, PsycINFO, and Web of Science. The original search returned 1802 results, with 1,116 from Web of Science, 626 from PubMed, 25 from Cochrane, and 35 from PsycINFO. After removing duplicates, 786 articles were chosen for the title and abstract screening processes. Finally, 112 full-text publications were deemed eligible, with 41 papers being included in this scoping review for analysis. A large proportion (32; 78.04%) of the studies chosen were cross-sectional, 14 (34.14%) of them reported general disability, 12 (29.26%) used a patient health questionnaire (PHQ-9) to measure depression, and 14 (34.14%) had interventions, including cognitive behavioral therapy, psychological counseling, social support, and physical activity. All interventions successfully reduced the severity of the depression. Cognitive behavioral therapies and psychological counseling were widely used interventions that had a significant impact on reducing depression. More randomized controlled trials are required, and they should focus on individuals with specific disabilities to provide disability-specific care that can improve the quality of life for disabled individuals.

The impact of modifiable health metrics on mortality for older adults with low cognitive function

Objectives

Cognitive impairment has emerged as a major contributing factor to mortality for older adults. Identifying the strong modifiable health metrics against mortality is of high priority, especially in this high-risk population.

Methods

This population-based study used data of US adults aged≥60 years old from the National Health and Nutrition Examination Survey 2011-2014 cycles. De-identified data for participants who completed cognitive function test were extracted. Mortality data was obtained by linking to the 2019 public-use linked mortality file.

Results

Participants with low global cognition had higher risk of all-cause mortality (HR = 1.46; 95%CI, 1.04-2.05). The highest prevalence of ideal level of health metrics was observed for sleep duration (54.36% vs. 62.37%), and the lowest was noted for blood pressure (12.06% vs. 21.25%) for participants with low and average to high global cognition, respectively. Ideal status of physical activity and diet quality were significantly associated with all-cause mortality among participants with low global cognition (HR = 0.48, 95%CI: 0.28-0.82; HR = 0.63, 95%CI: 0.43-0.95). The corresponding population-attributable fractions were 26.58 and 15.90%, respectively.

Conclusion

Low cognitive function was associated with increased risk of all-cause death for older adults. Attainment of healthy metrics, especially sufficient physical activity, consuming healthy diet and being never smoked, provided strong protection against death risk.

Cognitive performance and all-cause mortality in community dwellers of Amerindian ancestry living in rural Ecuador: A population-based, longitudinal prospective study

OBJECTIVE

There is limited information on mortality risk in individuals with cognitive impairment living in rural Latin America. In this study, we assess the association between cognitive impairment and all-cause mortality in adults of Amerindian ancestry living in rural Ecuador.

PATIENTS AND METHODS

Middle-aged and older adults enrolled in the population-based Three Villages Study cohort were followed prospectively in order to estimate mortality risk according to their baseline cognitive performance as determined by the Montreal Cognitive Assessment (MoCA). Results were adjusted for demographics, level of education, traditional cardiovascular risk factors, symptoms of depression, severe tooth loss, and oily fish intake (factors previously associated with mortality in the study population).

RESULTS

Analysis included 1022 individuals followed for an average of 7.8 ± 3.4 years. Mean MoCA score was 21.2 ± 5.4 points (median: 22 points), with 334 (32.7%) individuals showing cognitive impairment, as evidenced by a MoCA score ≤ 19 points (the cutoff for poor cognitive performance based on previous studies in the same population). A total of 150 (14.7%) individuals died during the follow-up. Crude mortality rate was 2.87 per 100 person-years (95% C.I.: 2.08 - 3.96). For individuals with normal cognition, the mortality rate was 1.21 (95% C.I.: 0.92 - 1.50) while for those with cognitive impairment the rate increased to 3.48 (95% C.I.: 2.73 - 4.23). A multivariate Cox-proportional hazards model, confirmed that individuals with cognitive impairment had a significantly higher mortality risk than those without cognitive impairment (HR: 1.52; 95% C.I.: 1.05 - 2.18).

CONCLUSIONS

Cognitive impairment is associated with mortality in the study population.