Adverse events in older adults and the risk of dementia and cognitive decline

Life Events and Incident Dementia: A Prospective Study of 493,787 Individuals Over 16 Years

OBJECTIVES

Life events can be stressful and have a detrimental impact on health, but evidence is inconclusive regarding life events and dementia risk. The present study tests whether life events are associated with incident dementia, whether experiencing multiple events has cumulative effects, and whether the associations vary across age, sex, race/ethnicity, socioeconomic status, and genetic vulnerability.

METHODS

UK Biobank participants (N = 493,787) reported on 6 life events that occurred within the past 2 years: serious illness, injury, assault to yourself or close relative, death of a spouse/partner or close relative, marital separation/divorce, and financial problems. Incident all-cause dementia was ascertained through health records from the UK National Health Service over a 16-year follow-up.

RESULTS

Serious illness, injury, or assault to yourself, marital separation/divorce, and financial difficulties were associated with a higher risk of dementia; serious illness, injury, or assault of a close relative was associated with a lower risk of dementia. When combined, experiencing 3-4 events was associated with a more than 2-fold increase in dementia risk. The association for marital separation/divorce was stronger within the first 5 years of follow-up (consistent with reverse causality). Death of a spouse/partner or close relative was mostly unrelated to dementia risk. With few exceptions, the associations were similar across age, sex, race/ethnicity, socioeconomic status, and apolipoprotein E e4 status groups.

DISCUSSION

Severe illness, injury, or personal assault, marital separation or divorce, and financial hardships may raise risk of dementia, particularly when these events occur together.

Distress Symptoms of Old Age and Mild Cognitive Impairment are Two Distinct Dimensions in Older Adults Without Major Depression

Background

Studies in old adults showed bidirectional interconnections between amnestic mild cognitive impairment (aMCI) and affective symptoms and that adverse childhood experiences (ACE) may affect both factors. Nevertheless, these associations may be confined to older adults with clinical depression.

Aim

To delineate the relationship between clinical symptoms of aMCI and affective symptoms in older adults without major depression (MDD) or dysfunctions in activities of daily living (ADL).

Methods

This case-control study recruited 61 participants with aMCI (diagnosed using Petersen's criteria) and 59 older adults without aMCI and excluded subjects with MDD and ADL dysfunctions.

Results

We uncovered 2 distinct dimensions, namely distress symptoms of old age (DSOA), comprising affective symptoms, perceived stress and neuroticism, and mild cognitive dysfunctions, comprising episodic memory test scores, the total Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. A large part of the variance (37.9%) in DSOA scores was explained by ACE, negative life events (health and financial problems), a subjective feeling of cognitive decline, and education (all positively). ACE and NLE have a highly significant impact on the DSOA score and are not associated with aMCI or its severity. Cluster analysis showed that the diagnosis of aMCI is overinclusive because some subjects with DSOA symptoms may be incorrectly classified as aMCI.

Conclusion

The clinical impact is that clinicians should carefully screen older adults for DSOA after excluding MDD. DSOA might be misinterpreted as aMCI.

Negative Wealth Shock and Cognitive Decline and Dementia in Middle-Aged and Older US Adults

Importance

As a financial hardship, negative wealth shock has been implicated in some adverse health outcomes. However, associations between negative wealth shock and cognitive decline and dementia have not been examined.

Objective

To investigate whether negative wealth shock was associated with cognitive decline and incident dementia among middle-aged and older US adults.

Design, Setting, and Participants

The Health and Retirement Study (HRS) is a prospective cohort study conducted biennially among US adults older than 50 years. Data from the HRS from calendar years 1996 to 2020 were analyzed from July 1 to 31, 2023. The final sample included 8082 participants with complete data of interest.

Exposures

Wealth status was quantified with questionnaires. Negative wealth shock was defined as a loss of 75% or more in total wealth over a 2-year period. Asset poverty was defined as zero or less total net wealth.

Main Outcomes and Measures

Cognitive function was assessed with the modified Telephone Interview for Cognitive Status (TICS-m). Dementia status was determined with TICS-m scores and proxy assessment.

Results

Among 8082 participants included (mean [SD] age, 63.7 [5.7] years; 4179 women [51.7%] and 3903 men [48.3%]; 1111 Black [13.7%], 6689 White [82.7%], and 282 other [3.5%]), 1441 developed incident dementia over a median follow-up time of 14 (IQR, 7-20) years. Compared with participants who had positive wealth without shock, those with negative wealth shock had accelerated cognitive decline (β coefficient, -0.014 [95% CI, -0.027 to -0.001]; P = .03) and increased risks of dementia (hazard ratio [HR], 1.27 [95% CI, 1.11-1.46]; P < .001). Higher dementia risks were also found in participants with asset poverty at baseline (HR, 1.61 [95% CI, 1.30-2.00]; P < .001). Associations were found in White participants (HR, 1.34 [95% CI, 1.14-1.58]; P < .001) and participants younger than 65 years (HR, 1.38 [95% CI, 1.13-1.68]; P = .001) but not in other races and ethnicities or those 65 years or older.

Conclusions and Relevance

In this cohort study, negative wealth shock was associated with accelerated cognitive decline and elevated risks of dementia among middle-aged and older US adults, with modifications by age and ethnicity. These findings should be confirmed by further prospective and interventional studies.

The association between adverse events in later life and mortality in older individuals

Background

Stress can have adverse impacts on health, particularly when it is chronic or resulting from major adverse events. Our study investigated whether relatively common adverse events in older individuals were associated with an increased risk of death, as well as cause-specific death and potential gender differences.

Methods

Participants were 12896 community-dwelling Australians aged ≥70 years at enrolment into the ASPREE (ASPirin in Reducing Events in the Elderly) study and without known life-limiting disease. A questionnaire administered in the year after enrolment, collected information on ten adverse events experienced in the past year. Mortality status was verified by multiple sources including health records and the National Death Index across a maximum of 10 years. Underlying causes of death were determined using clinical information by two adjudicators. Cox-proportional hazards regression models were used to estimate mortality risk.

Results

Two of the ten adverse events were associated with an increased risk of mortality in fully adjusted models. A 69% increased risk of mortality was observed in participants who reported their spouse/partner had recently died (95% CI: 1.19-2.39, P < 0.01). Cancer-related but not cardiovascular deaths also increased. Participants with a seriously ill spouse/partner also had a 23% increased risk of mortality (HR: 1.23, 95% CI: 1.02-1.48, P = 0.03). There was a tendency for these associations to be stronger among men than women.

Limitations

Perceived stress and cortisol were not measured, thus limiting our understanding of the psychological and physiological impacts of adverse events.

Conclusions

Experiencing adverse events in later-life, especially the death of a spouse/partner, may be a risk factor for earlier mortality. These findings may increase public health awareness and better inform initiatives for particular groups, including bereaved men.

Biological Embedding of Early-Life Adversity and a Scoping Review of the Evidence for Intergenerational Epigenetic Transmission of Stress and Trauma in Humans

Severe or chronic stress and trauma can have a detrimental impact on health. Evidence suggests that early-life adversity can become biologically embedded and has the potential to influence health outcomes decades later. Epigenetics is one mechanism that has been implicated in these long-lasting effects. Observational studies in humans indicate that the effects of stress could even persist across generations, although whether or not epigenetic mechanisms are involved remains under debate. Here, we provide an overview of studies in animals and humans that demonstrate the effects of early-life stress on DNA methylation, one of the most widely studied epigenetic mechanisms, and summarize findings from animal models demonstrating the involvement of epigenetics in the transmission of stress across generations. We then describe the results of a scoping review to determine the extent to which the terms intergenerational or transgenerational have been used in human studies investigating the transmission of trauma and stress via epigenetic mechanisms. We end with a discussion of key areas for future research to advance understanding of the role of epigenetics in the legacy effects of stress and trauma.