The Risk of Dementia May Be Directly Elevated by Traumatic Life Events

 

The Risk of Dementia May Be Directly Elevated by Traumatic Life Events

In a recent publication by BMC Geriatrics, researchers delved into the connection between traumatic life events (TLE) and the heightened risk of all-cause dementia in individuals aged 60 and above.

The comprehensive review incorporated data from 276,570 participants across various studies, with their median age ranging from 50.3 to 77 years and a follow-up period spanning from two to 37 years (averaging at 9.5 years).

Background:

Previous research has posited that experiencing TLEs, encompassing events like real or threatened death, injury, and sexual violence, might be associated with an increased risk of dementia.

The global economic burden of dementia is estimated at a staggering one trillion USD annually. Given projections that over 150 million people will grapple with dementia by 2050, the identification and targeting of modifiable risk factors have become paramount in the quest to mitigate dementia.

While systematic reviews have previously hinted at a link between post-traumatic stress disorder (PTSD) and dementia, none have specifically explored the potential relationship between TLEs and dementia risk.

It is essential to ascertain whether TLEs identified during PTSD diagnosis or diagnosed independently pose a risk factor for dementia. Such understanding could pave the way for interventions aimed at mitigating dementia risk and delaying its onset.

About the Study:

In the present study, researchers conducted a systematic review and a meta-analysis using generic inverse variance random effects to gauge the impact of TLEs on dementia risk, presenting their findings as risk ratios, odds ratios, and hazard ratios (HRs). They employed the Life Events Checklist for DSM-5 (LEC-5) criteria to identify TLEs.

All studies included were original research articles, published in peer-reviewed journals, and employed either case-control or cohort study designs. These studies specified dementia diagnosis as an outcome in study populations comprising at least 60 individuals.

All studies centered on all-cause dementia, covering various degrees of severity, and were conducted across diverse recruitment settings. They excluded cases of early-onset dementia with different etiologies. Information about various TLEs, such as childhood trauma, was sourced from participants, their informants, or medical records.

The search strategy encompassed databases like PsychINFO, Embase, and MEDLINE, covering data from inception to April 20, 2022, using keywords such as "dementia," "risk," and "traumatic events."

The team then imported all the retrieved studies into Covidence systematic review software. Two independent reviewers rigorously screened all articles at each stage, adhering strictly to inclusion and exclusion criteria.

The Newcastle–Ottawa Scale (NOS) was employed to assess the quality of non-randomized epidemiological studies (NOS), considering three domains: selection, comparability, and outcome. Additionally, a funnel plot was utilized to gauge publication bias within the included studies.

Researchers categorized studies as 'Good' if they secured ≥3 stars in the selection and comparability domains and ≥3 stars in the outcome domain. 'Fair' and 'Poor' quality classifications were also assigned when applicable.

Ultimately, the team pooled and analyzed all the studies. Sub-analyses were performed, stratifying by trauma type, and the I2 statistic was employed to measure heterogeneity. Sensitivity analyses were also conducted, incorporating studies reporting HRs and deemed high quality.

Results:

Out of 3,523 studies initially screened, 29 research papers underwent full-text examination. Seven studies were ultimately included in the meta-analysis—a cross-sectional study, three prospective cohort studies, and three retrospective cohort studies.

The pooled results from these seven studies revealed that TLEs were associated with an increased risk of all-cause dementia (HR = 1.21). However, these results exhibited significant heterogeneity (I2 = 78%).

Furthermore, the researchers observed that specific trauma subtypes, such as those occurring during wartime and in childhood, also heightened the risk of all-cause dementia (pooled HR = 1.28), although this was based on a smaller subset of studies (n=3). These results similarly exhibited significant heterogeneity (I2 = 75%).

Conclusions:

Overall, this study underscores the potential modifiability of TLEs as risk factors linked to an elevated risk of all-cause dementia.

Understanding the mechanisms through which TLEs increase susceptibility to dementia may pave the way for targeted interventions aimed at mitigating the impact of trauma, including PTSD, on dementia.

Future research endeavors should delve into the specific factors related to TLEs, including their chronicity and severity, as well as individual factors like age and their association with various dementia subtypes.