Family member deaths across adulthood predict Alzheimer's disease risk: The Cache County Study

Effect modifications of BMI transition and trajectory in the associations of adverse childhood experiences with new-onset dementia and its subtypes in older US adults

Background

Adverse childhood experiences (ACEs) and dementia are associated and comorbid with obesity. However, according to emerging research, the role of obesity in the association between ACEs and dementia seems controversial.

Aims

This analysis aimed to explore the associations between ACEs and different dementia subtypes and the effect modification of long-term body mass index (BMI).

Methods

Data were obtained from the US Health and Retirement Study. Six ACEs were categorised as 0, 1 and 2 or more. All-cause dementia, Alzheimer's disease (AD) and other dementias were defined by self-reported or proxy-reported physician diagnosis. Cox proportional hazards regression was used to explore the associations of ACEs with new-onset all-cause dementia, AD and other dementias from 2010 to 2020. Effect modification of BMI in 2010 and BMI transition and trajectory (fitted by group-based trajectory modelling) from 2004 to 2010 were assessed.

Results

15 282 participants with a mean age of 67.0 years (58.0-75.0) were included in the 2010 data analysis. Significant interactions of ACEs with baseline BMI, BMI transition and BMI trajectory in their associations with new-onset all-cause dementia and AD were observed (all p<0.05). For instance, positive associations of two or more ACEs (vs none) with all-cause dementia and AD were found in those with a BMI trajectory of maintaining ≥30 kg/m2 (maintain obesity) rather than a decline to or maintaining <25 kg/m2 (decline to or maintain normal weight), with hazard ratios (HRs) of 1.87 (95% confidence interval (CI): 1.45 to 2.42) and 1.85 (95% CI: 1.22 to 2.80), respectively.

Conclusions

ACEs were associated with dementia and AD in US adults with long-term abnormally elevated BMI but not with long-term normal or decreasing BMI. Integrated weight management throughout life could prevent dementia among those with childhood adversity.

Childhood socio-economic circumstances and dementia: prospective register-based cohort study of adulthood socio-economic and cardiovascular health mediators

Background

This study analysed the association between childhood socio-economic circumstances and the risk of dementia, and investigated the mediating role of potentially modifiable risk factors including adulthood socio-economic position and cardiovascular health.

Methods

We used a 10% sample of the 1950 Finnish population census linked with subsequent population and health registers (n = 95 381). Information of socio-economic characteristics, family structure and housing conditions at the age of 0–15 years was obtained from the 1950 census. We identified cohort members who developed dementia in 2000–2018 using national hospital, medication and death registers. Discrete time survival analysis using logistic regression and mediation analysis applying the Karlson–Holm–Breen (KHB) method were employed.

Results

An excess risk of dementia was observed for household crowding [odds ratio (OR) = 1.10; 95% CI 1.02–1.18 for 3 to &lt;4 persons per heated room; OR = 1.19; 95% CI 1.11–1.27 for ≥4 persons], single-father family (OR = 1.27; 95% CI 1.07–1.51) and eastern and northern region of residence (OR = 1.19; 95% CI 1.10–1.28). The effects of single-father family and region of residence were mostly direct with adulthood characteristics mediating 14% and 29% of the total effect, respectively. The largest indirect effect was observed for household crowding mediated through adulthood socio-economic position (47–65%).

Conclusions

The study shows that childhood socio-economic circumstances are associated with dementia, and that the underlying mechanisms only partly relate to adulthood socio-economic position and cardiovascular health. Socio-economic and health interventions targeted at families with children may carry long-term benefits by contributing to a lower dementia risk in later life.

The Relationship Between Adverse Childhood Experiences and Alzheimer's Disease: A Systematic Review

Background

Alzheimer's disease is a global health concern, and with no present cure, prevention is critical. Exposure to adverse childhood experiences may increase the risk of developing Alzheimer's disease. This systematic review was conducted to synthesize the evidence on the associations between adverse childhood experiences (<18 years) and the risk of Alzheimer's disease in adulthood.

Methods

A search strategy was developed and conducted to identify articles investigating the associations between exposure to adverse childhood experiences and the onset of Alzheimer's disease by searching key databases (CINAHL, MEDLINE and PsycInfo). Two reviewers independently determined the eligibility of studies according to pre-determined criteria, and assessed the methodological quality using the US National Heart, Lung and Blood Institute 14-item checklist for observational cohort and cross-sectional studies, respectively. Due to limited studies, a descriptive synthesis was performed. The protocol for this review is published in BMJ Open and registered with PROSPERO (CRD42020191439).

Results

Our search yielded 781 articles, of which three (two separate analyses from the same cohort study and one cross-sectional study) met the predetermined eligibility criteria. The methodological quality assessment yielded an overall mean score of 78.9% (range 66.6 – 84.6%). All studies found adverse childhood experiences were associated with an increased risk of Alzheimer's disease. However, there was a limited number of available studies to inform the synthesis.

Conclusions

Adverse childhood experiences appear to be associated with an increased risk of Alzheimer's disease, although, further research is needed.

Registration and Protocol

The protocol for this review is registered with PROSPERO (CRD42020191439) and published with BMJ Open (Corney et al., 2021).

Sibling Deaths, Racial/Ethnic Disadvantage, and Dementia in Later Life

OBJECTIVES

Sibling loss is understudied in the bereavement and health literature. The present study considers whether experiencing the death of siblings in mid-to-late life is associated with subsequent dementia risk and how differential exposure to sibling losses by race/ethnicity may contribute to racial/ethnic disparities in dementia risk.

METHODS

We use discrete-time hazard regression models, a formal mediation test, and a counterfactual simulation to reveal how sibling loss in mid-to-late life affects dementia incidence and whether unequal exposures by race/ethnicity mediate the racial/ethnic disparities in dementia. We analyze data from the Health and Retirement Study (2000-2016). The sample includes 13,589 respondents (10,607 non-Hispanic White, 1,761 non-Hispanic Black, and 1,158 Hispanic adults) aged 65 years and older in 2000 who show no evidence of dementia at baseline.

RESULTS

Discrete-time hazard regression results show that sibling loss in mid-to-late life is associated with up to 54% higher risk for dementia. Sibling loss contributes to Black-White disparities in dementia risk. In addition, a simulation analysis shows that dementia rates would be 14% lower for Black adults if they experienced the lower rates of sibling loss experienced by White adults. This pattern was not observed among Hispanic adults.

DISCUSSION

The death of a sibling in mid-to-late life is a stressor that is associated with increased dementia risk. Black adults are disadvantaged in that they are more likely than Whites to experience the death of siblings, and such losses contribute to the already substantial racial/ethnic disadvantage in dementia.

Parental Death and Cognitive Impairment: An Examination by Gender and Race-ethnicity

OBJECTIVES

We provide the first nationally representative longitudinal study of cognitive impairment in relation to parental death from childhood through early adulthood, midlife, and later adulthood, with attention to heterogeneity in the experience of parental death.

METHOD

We analyzed data from the Health and Retirement Study (2000-2016). The sample included 13,392 respondents, contributing 72,860 person-periods. Cognitive impairment was assessed using the modified version of the Telephone Interview for Cognitive Status (TICS). Discrete-time hazard regression models were estimated to predict the odds of cognitive impairment.

RESULTS

Both exposure and timing of parental death were related to risk of cognitive impairment in late life and associations vary by gender. The detrimental effect of a father's death was comparable for daughters and sons although exposure to mother's death had stronger effects on daughter's than son's risk of cognitive impairment. Father's death at younger ages had the strongest effect on sons' late-life risk of cognitive impairment whereas mother's death in middle adulthood had the strongest effect on daughters' risk. We found no significant racial-ethnic variation in the association between parental death and cognitive impairment.

DISCUSSION

It is important to explore the gender-specific pathways through which parental death leads to increased risk of cognitive impairment so that effective interventions can be implemented to reduce risk.

Accuracy of general hospital dementia diagnoses in England: Sensitivity, specificity, and predictors of diagnostic accuracy 2008-2016

INTRODUCTION

Recognizing dementia in general hospitals allows for tailored care. We aimed to assess hospital dementia diagnosis accuracy, changes over time, and predictors of correct identification.

METHOD

Retrospective cohort study of people over 65 years, using data from a large mental health care database as gold standard, linked to 2008-2016 English hospital data.

RESULTS

In 21,387 people who had 138,455 admissions, we found sensitivity and specificity of dementia recording, respectively, to be 78.0% and 92.0% for each person's complete records, and 63.3% and 96.6% for each nonelective admission. Diagnostic sensitivity increased between 2008 and 16. Accurate general hospital recording of the presence of dementia was lower in ethnic minority groups, younger, single people, and those with physical illness.

DISCUSSION

Dementia diagnosis recording in general hospitals is increasing but remains less likely in some groups. Clinicians should be aware of this inequity and have a higher index of clinical suspicion in these groups.