Mild and moderate cognitive impairment and mortality among Brazilian older adults in long-term follow-up: The Bambui Health Aging Study

Role of cognitive impairment in predicting the long-term risk of all-cause mortality: a 20-year prospective cohort study in China

BACKGROUND

There is limited evidence of the relationship between cognitive changes and all-cause mortality. And it has no report of population-attributable fraction (PAF) of mortality due to cognitive impairment in Chinese elderly. In light of this, we comprehensively examined the relationship between cognitive impairment and all-cause mortality after 20-year follow-up among the elderly Chinese.

METHODS

This is an epidemiological survey with a 20-year prospective cohort study design. A total of 9093 participants came from the Chinese Longitudinal Healthy Longevity Survey 1998-2018 waves. Cox proportional hazards regressions were performed to analyze the relationship between baseline cognitive impairment status, the rate of change in the MMSE scores over two years and subsequent all-cause mortality.

RESULTS

We observed a dose-response relationship between cognition and mortality. Compared to those with no impairment, elderly with mild (AHR = 1.11, 95% CI 1.05-1.18), moderate (AHR = 1.22, 95% CI 1.13-1.33) and severe (AHR = 1.30, 95% CI 1.19-1.42) cognitive impairment showed increased mortality risk. Elderly with rapid cognitive decline had 24% higher mortality risk than those with stable cognitive (AHR = 1.24, 95%CI 1.10-1.39). The PAF of mortality due to severe cognitive impairment was 3.69% (95%CI:2.36-5.25%). Impairment in the subdomain of naming foods (AHR = 1.12, 95% CI 1.04-1.21), registration (AHR = 1.18, 95% CI 1.11-1.26), attention and calculation (AHR = 1.13, 95% CI 1.07-1.21), copy figure (AHR = 1.13, 95% CI 1.06-1.20), delayed recall (AHR = 1.14, 95% CI 1.07-1.20) and language (AHR = 1.14, 95% CI 1.05-1.24) were independently associated with increased mortality risk among participants.

CONCLUSION

Baseline cognitive impairment was inversely associated with longevity among the elderly Chinese. The rapid cognitive decline increased all-cause mortality, and this risk would continue for 20 years. These findings underscore the crucial role of early detection and management of cognitive impairment in the elderly.

The association between disability and all-cause mortality in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

There are 1·3 billion people with disabilities globally. On average, they have poorer health than their non-disabled peers, but the extent of increased risk of premature mortality is unknown. We aimed to systematically review the association between disability and mortality in low-income and middle-income countries (LMICs).

METHODS

We searched MEDLINE, Global Health, PsycINFO, and EMBASE from Jan 1, 1990 to Nov 14, 2022. Longitudinal epidemiological studies in any language with a comparator group that measured the association between disability and all-cause mortality in people of any age were eligible for inclusion. Two reviewers independently assessed study eligibility, extracted data, and assessed risk of bias. We used a random-effects meta-analysis to calculate the pooled hazard ratio (HR) for all-cause mortality by disability status. We then conducted meta-analyses separately for different impairment and age groups.

FINDINGS

We identified 6146 unique articles, of which 70 studies (81 cohorts) were included in the systematic review, from 22 countries. There was variability in the methods used to assess and report disability and mortality. The meta-analysis included 54 studies, representing 62 cohorts (comprising 270 571 people with disabilities). Pooled HRs for all-cause mortality were 2·02 (95% CI 1·77-2·30) for people with disabilities versus those without disabilities, with high heterogeneity between studies (τ2=0·23, I2=98%). This association varied by impairment type: from 1·36 (1·17-1·57) for visual impairment to 3·95 (1·60-9·74) for multiple impairments. The association was highest for children younger than 18 years (4·46, [3·01-6·59]) and lower in people aged 15-49 years (2·45 [1·21-4·97]) and people older than 60 years (1·97 [1·65-2·36]).

INTERPRETATION

People with disabilities had a two-fold higher mortality rate than people without disabilities in LMICs. Interventions are needed to improve the health of people with disabilities and reduce their higher mortality rate.

FUNDING

UK National Institute for Health and Care Research; and UK Foreign, Commonwealth and Development Office.

Associations of cognitive impairment and longitudinal change in cognitive function with the risk of fatal stroke in middle-aged to older Chinese

It is unclear whether cognitive impairment and the longitudinal change in cognition are associated with the risk of fatal stroke in aging populations. Based on the Guangzhou Biobank Cohort Study data a sum of 26,064 participants at baseline and all deaths caused by stroke in a mean follow-up of 14.3 years (standard deviation = 3.2) were included, and the Cox proportional hazard regression was used in this prospective cohort study. Cognitive impairment was respectively associated with an increased risk of fatal strokes (the adjusted hazard ratio (aHR) = 1.38, 95% CI1.16-1.64, P < 0.001) and fatal ischaemic stroke (aHR = 1.39, 95% CI1.10-1.77, P = 0.007), compared to median cognition; the Delayed Word Recall Test (DWRT) score was associated with a decreasing trend for the risk of fatal strokes in a restricted cubic spline analysis; the longitudinal DWRT score decline was associated with the increased risks of fatal strokes (aHR = 1.42, 95% CI 1.11-1.82, P = 0.006) and fatal haemorrhagic stroke (aHR = 1.75, 95% CI 1.10-2.78, P = 0.02), compared to the longitudinal DWRT score rise. In summary, cognitive impairment and the longitudinal decline in DWRT scores were associated with the increased risk of fatal strokes; early screening of cognitive function should be conducive to predictive intervention in fatal stroke among relatively healthy middle-aged to older populations.

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.

Patients with Cognitive Impairment in Parkinson's Disease Benefit from Deep Brain Stimulation: A Case-Control Study

Background

Deep brain stimulation (DBS) for Parkinson's disease (PD) is generally contraindicated in persons with dementia but it is frequently performed in people with mild cognitive impairment or normal cognition, and current clinical guidelines are primarily based on these cohorts.

Objectives

To determine if moderately cognitive impaired individuals including those with mild dementia could meaningfully benefit from DBS in terms of motor and non-motor outcomes.

Methods

In this retrospective case-control study, we identified a cohort of 40 patients with PD who exhibited moderate (two or more standard deviations below normative scores) cognitive impairment (CI) during presurgical workup and compared their 1-year clinical outcomes to a cohort of 40 matched patients with normal cognition (NC). The surgery targeted subthalamus, pallidus or motor thalamus, in a unilateral, bilateral or staged approach.

Results

At preoperative baseline, the CI cohort had higher Unified Parkinson's Disease Rating Scale (UPDRS) subscores, but similar levodopa responsiveness compared to the NC cohort. The NC and CI cohorts demonstrated comparable degrees of postoperative improvement in the OFF-medication motor scores, motor fluctuations, and medication reduction. There was no difference in adverse event rates between the two cohorts. Outcomes in the CI cohort did not depend on the target, surgical staging, or impaired cognitive domain.

Conclusions

Moderately cognitively impaired patients with PD can experience meaningful motor benefit and medication reduction with DBS.

Cognitive Frailty is Associated With Elevated Proinflammatory Markers and a Higher Risk of Mortality

BACKGROUND

Cognitive impairment and physical frailty are common among older adults and associated with a higher likelihood of adverse health outcomes. These two conditions frequently coexist in the same individual as cognitive frailty, yet few studies have examined the impact of such comorbidity on clinical outcomes or underlying biological mechanisms.

METHODS

A total of 1,340 older adults (age ≥60 years old) from the Bambui Cohort Study of Ageing, with a total follow-up of 10 years, were included in this study. Frailty was defined by the accumulation of deficit framework and cognitive impairment based on scores on the MMSE less than 22. In addition, serum IL-6 levels were measured by cytometric bead array assay.

RESULTS

Individuals classified with cognitive frailty had significantly higher serum IL-6 levels compared to the robust, cognitively unimpaired group. Those with cognitive frailty (aOR = 1.97 [1.18-3.27] and prefrailty and cognitive impairment (aOR = 1.83 [1.24-2.69]) had the highest mortality risk over 10 years of follow-up. Higher IL-6 levels were also independently associated with a higher mortality rate (aOR = 1.37 [1.23-1.54]).

CONCLUSION

Our study shows that cognitive Frailty indicates a vulnerability state and of increasing mortality risk. Our findings also suggested that proinflammatory abnormalities can be viewed as a central phenomenon underlying common age-related problems (e.g., cognitive impairment and Frailty) and outcomes (e.g., mortality).

Changes in prevalence of cognitive impairment and associated risk factors 2000-2015 in São Paulo, Brazil

INTRODUCTION

Decreases in prevalence of cognitive impairment and dementia over the last two decades have been observed in different countries for cohorts entering older age. This study aimed to assess the cognitive impairment prevalence and explore associated factors among subjects aged >60 living in São Paulo, Brazil.

METHOD

Data came from a population-based Health, Welfare and Aging survey conducted in 2000, 2006, 2010, and 2015. Cognitive impairment was detected using the abbreviated Mini-Mental State Exam corrected by formal education years. In total, there were 5922 respondents in the statistical analyses.

RESULTS

Logistic regression models adjusted for age group, income, race, cardiovascular risk factors, and depression were used to estimate cognitive impairment prevalence. Between 2015 and 2000, respondents were more likely to report formal education, hypertension, diabetes, and overweight/obesity. Moreover, the weighted analyses showed that cognitive impairment prevalence was higher in 2015, even adjusting for sociodemographic and socioeconomic characteristics, cardiovascular risk factors, and depression.

CONCLUSION

In contrast to decreases in cognitive impairment prevalence in other countries and despite increases in educational years, our findings suggest no secular improvements in cognitive health for the 2015 wave of older adults residing in São Paulo.

Cognitive function assessed by Mini-mental state examination and risk of all-cause mortality: a community-based prospective cohort study

BACKGROUND

The Mini-Mental State Examination (MMSE) is the most widely used instrument to test cognitive functioning. The present study prospectively investigated the association between MMSE scores, MMSE domains, and all-cause mortality.

METHODS

A total of 2134 participants aged 60 years or over, selected from one urban community-dwelling population in China, were enrolled in the study. The cognitive test was performed by use of the MMSE at baseline, and covariates were recorded simultaneously. Cox regression models were used for examining the cognitive function, expressed by different MMSE transformations, and all-cause mortality. After followed up for a median of 10.8 years (ranging from 1.0 to 11.3 years), loss to follow-up was 13.1% and 1854 individuals were finally included in the analyses.

RESULTS

The subjects had the mean (SD) age of 71.01 (7.00) years, and 754 (40.67%) of them were women. Per point increase on MMSE scores was associated a 4% decreased risk of all-cause mortality [hazard ratio (HR): 0.96; 95%confidence interval (CI): 0.93-0.98]; compared to MMSE scores of ≥24, MMSE scores of < 24 was associated with a 43% increased risk of all-cause mortality (HR: 1.43; 95% CI: 1.05-1.95); compared to MMSE scores of 30, MMSE scores of 27-29 (HR: 1.27; 95% CI: 0.89-1.82), 24-26 (HR: 1.30; 95% CI: 0.86-1.99), and < 24 (HR: 1.79; 95% CI: 1.15-2.77) had a graded increase in risk of all-cause mortality (p for trend =0.003). Of MMSE domains, orientation to time (HR: 2.00; 95% CI: 1.29-3.11), attention and calculation (HR: 1.49; 95% CI: 1.16-1.92), recall (HR: 2.59; 95% CI: 1.22-5.47), and language (HR: 1.68; 95% CI: 1.25-2.26) were significantly associated with all-cause mortality in the unadjusted model; for one increase in the number of impaired MMSE domains, the unadjusted HR (95% CI) of mortality is 1.51 (1.38, 1.65), and the HR (95% CI) of mortality is 1.12 (1.01, 1.25) with full adjustment; compared to 0 and 1 impaired MMSE domains, the HRs of all-cause mortality associated with 2, 3, 4, and ≥ 5 impaired MMSE domains were 1.14 (95% CI: 0.84-1.54), 1.50 (95% CI: 0.98-2.28), 2.14 (95% CI: 1.12-4.09) and 2.29 (95% CI: 1.24-5.04), respectively, and a dose-dependent relationship was significant (p for trend =0.003).

CONCLUSION

Cognitive impairment is associated with the increased risk of all-cause mortality in the Chinese elderly. Similarly, reduced MMSE scores, as well as impaired MMSE domains, are also associated with the increasing risk of all-cause mortality.