Living Alone During Old Age and the Risk of Dementia: Assessing the Cumulative Risk of Living Alone

Low income, being without employment, and living alone: how they are associated with cognitive functioning-Results from the German national cohort (NAKO)

Aim was to investigate to what extent cognitive functioning differs by three socioeconomic conditions: low income, being without employment, and living alone. A total of N = 158,144 participants of the population-based German National Cohort (NAKO) provided data on socioeconomic conditions and completed cognitive tests. Multivariable confounder-adjusted regression analyses indicated that cognitive functioning was lower in those with low income (b = -0.21) compared to not having low income, living alone (b = -0.04) compared to not living alone, and being without employment (b = -0.09) compared to being employed. An interaction with age indicated that the difference in cognitive functioning was getting larger with age between the income groups and living alone status groups. Accordingly, the three conditions appear independently associated with poorer cognitive functioning. Pathways of how cognitive health in this population group can be improved need to be explored.

All-cause and cause-specific mortality risks in individuals with diabetes living alone: A large-scale population-based cohort study

AIMS

The rise in one-person households is a global trend. We aimed to investigate mortality risk in individuals with diabetes living alone (IDLA) using a large-scale population-based database.

METHODS

A total of 2,447,557 adults with type 2 diabetes were identified from the Korean National Health Information Database. One-person households were defined based on the number of registered family members. The risks of all-cause and cause-specific mortalities were estimated using a multivariable Cox proportional hazards regression model.

RESULTS

During a median follow-up period of 6.0 years, 191,084 deaths (7.8 %) occurred. IDLA had a higher risk of mortality compared to those not living alone after adjusting for potential confounders (HR 1.20, 95 % CI: 1.18-1.22). This association was more prominent in younger individuals, men, and those with low income, and it was dependent on the duration of living alone. The risks of cause-specific mortality were all significantly higher in the IDLA group compared with the non-IDLA group. Adherence to favorable lifestyle behaviors was associated with a significant reduction in all-cause mortality, particularly in IDLA.

CONCLUSIONS

The elevated risk of mortality in IDLA highlights the need for tailored medical interventions and social assistance, particularly for those with unhealthy lifestyles or low income.

Social Isolation and Hospitalization in Community-Dwelling Older Adults by Dementia Status

BACKGROUND

Social isolation is a well-known risk factor for poor health outcomes, including incident dementia, yet its associations with outcomes among persons living with dementia are understudied. We examined the association between social isolation and hospitalization among a nationally representative sample of older adults with and without dementia.

METHODS

This observational cohort study included 5 533 community-dwelling Medicare beneficiaries from the 2015 and 2016 National Health and Aging Trends Study (NHATS). Using multivariable logistic regression analyses, we examined associations between social isolation and hospitalization in the following year, examining differences by dementia status. Social isolation was measured using a 4-item typology. Dementia was identified using a prespecified classification in NHATS.

RESULTS

20.7% of older adults were socially isolated. Social isolation was more prevalent among persons with dementia (35.4%) than among those without dementia (19.0%) (p < .001). Among persons with dementia, social isolation was associated with 1.68 greater odds of hospitalization (confidence interval [CI]: 1.23-2.28), translating into a 9% average increase in the predicted probability of hospitalization for persons with dementia who were socially isolated compared to those who were not (p = .001). In the combined sample that included persons with and without dementia, there was a significant moderation effect of dementia on the association between social isolation and hospitalization (odds ratio: 1.70; CI: 1.19-2.43).

CONCLUSIONS

For persons with dementia, social isolation is prevalent and associated with greater odds of subsequent hospitalization. Efforts to reduce acute healthcare utilization should explore ways to bolster social connection to improve health outcomes among persons with dementia.

Identification of profiles associated with conversions between the Alzheimer's disease stages, using a machine learning approach

BACKGROUND

The identification of factors involved in the conversion across the different Alzheimer's disease (AD) stages is crucial to prevent or slow the disease progression. We aimed to assess the factors and their combination associated with the conversion across the AD stages, from mild cognitive impairment to dementia, at a mild, moderate or severe stage and to identify profiles associated with earliest/latest conversion across the AD stages.

METHODS

In this study conducted on the real-life MEMORA cohort data collected from January 1, 2013, and December 31, 2019, three cohorts were selected depending on the baseline neurocognitive stage from a consecutive sample of patients attending a memory center, aged between 50 and 90 years old, with a diagnosis of AD during the follow-up, and with at least 2 visits at 6 months to 1 year of interval. A machine learning approach was used to assess the relationship between factors including socio-demographic characteristics, comorbidities and history of diseases, prescription of drugs, and geriatric hospitalizations, and the censored time to conversion from mild cognitive impairment to AD dementia, from the mild stage of dementia to the moderate or severe stages of AD dementia, and from the moderate stage of AD dementia to the severe stage. Profiles of earliest/latest conversion compared to median time to conversion across stages were identified. The median time to conversion was estimated with a Kaplan-Meier estimator.

RESULTS

Overall, 2891 patients were included (mean age 77±9 years old, 65% women). The median time of follow-up was 28 months for mild cognitive impairment (MCI) patients, 33 months for mild AD dementia and 30 months for moderate AD dementia. Among the 1264 patients at MCI stage, 61% converted to AD dementia (median time to conversion: 25 months). Among the 1142 patients with mild AD dementia, 59% converted to moderate/severe stage (median time: 23 months) and among the 1332 patients with moderate AD dementia, 23% converted to severe stage (Q3 time to conversion: 22 months). Among the studied factors, cardiovascular comorbidities, anxiety, social isolation, osteoporosis, and hearing disorders were identified as being associated with earlier conversion across stages. Symptomatic treatment i.e. cholinesterase inhibitors for AD was associated with later conversion from mild stage of dementia to moderate/severe stages.

CONCLUSION

This study based on a machine learning approach allowed to identify potentially modifiable factors associated with conversion across AD stages for which timely interventions may be implemented to delay disease progression.

Association between household size and risk of incident dementia in the UK Biobank study

Currently, the relationship between household size and incident dementia, along with the underlying neurobiological mechanisms, remains unclear. This prospective cohort study was based on UK Biobank participants aged ≥ 50 years without a history of dementia. The linear and non-linear longitudinal association was assessed using Cox proportional hazards regression and restricted cubic spline models. Additionally, the potential mechanisms driven by brain structures were investigated by linear regression models. We included 275,629 participants (mean age at baseline 60.45 years [SD 5.39]). Over a mean follow-up of 9.5 years, 6031 individuals developed all-cause dementia. Multivariable analyses revealed that smaller household size was associated with an increased risk of all-cause dementia (HR, 1.06; 95% CI 1.02-1.09), vascular dementia (HR, 1.08; 95% CI 1.01-1.15), and non-Alzheimer's disease non-vascular dementia (HR, 1.09; 95% CI 1.03-1.14). No significant association was observed for Alzheimer's disease. Restricted cubic splines demonstrated a reversed J-shaped relationship between household size and all-cause and cause-specific dementia. Additionally, substantial associations existed between household size and brain structures. Our findings suggest that small household size is a risk factor for dementia. Additionally, brain structural differences related to household size support these associations. Household size may thus be a potential modifiable risk factor for dementia.

Neighborhood Features and Cognitive Function: Moderating Roles of Individual Socioeconomic Status

INTRODUCTION

There is an interest in exploring the associations between neighborhood characteristics and individual cognitive function; however, little is known about whether these relationships can be modified by individual socioeconomic status, such as educational attainment and income.

METHODS

Drawing from the 2010-2018 Health and Retirement Study, this study analyzed 10,621 older respondents (aged 65+) with a total of 33,931 person-waves. These respondents did not have dementia in 2010 and stayed in the same neighborhood throughout the study period. Cognitive function was measured with a 27-point indicator biennially, and neighborhood characteristics (i.e., walkability, concentrated disadvantage, and social isolation) were assessed in 2010. All analyses were performed in 2023.

RESULTS

Cognitive function is positively associated with neighborhood walkability and negatively related to concentrated disadvantage, suggesting that exposures to these neighborhood characteristics have long-lasting impacts on cognitive function. Furthermore, individual socioeconomic status modifies the relationship between neighborhood characteristics and cognitive function. Compared with those graduating from college, respondents without a bachelor's degree consistently have lower cognitive function but the educational gap in cognitive function narrows with increases in walkability (b= -0.152, SE=0.092), and widens when neighborhood concentrated disadvantage (b=0.212, SE=0.070) or social isolation (b=0.315, SE=0.125) rises. The income gap in cognitive function shrinks with increases in walkability (b= -0.063, SE=0.027).

CONCLUSIONS

The moderating role of socioeconomic status indicates that low-socioeconomic status older adults who also live in disadvantaged neighborhoods face a higher risk of poor cognitive function. Low-education and low-income aging adults may have the most to gain from investments to improve neighborhood characteristics.

Association of living alone and living alone time with hypertension among Chinese men aged 80 years and older: a cohort study

Objective

There is little evidence of the influence of living alone on hypertension risk among men 80 years or older. Additionally, the influence of living alone duration on hypertension risk lacks thorough investigation. Hence, this cohort study examines living alone and its duration's link to hypertension risk in this specific group.

Methods

We included 2009 older men aged ≥80 years without hypertension from the Chinese Longitudinal Healthy Longevity Survey in the 2008 wave. Follow-up was conducted in the 2011 wave. Multivariable Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) to assess hypertension risk related to living alone and living alone time.

Results

We included 2,009 older men, with a mean age of 90.7 years (standard deviation: 6.8). Over a median follow-up of 2.9 (1.3-3.0) years, 573 participants (28.5%) developed hypertension. Living alone was significantly associated with a higher hypertension risk than living with family (HR: 1.42; 95% CI 1.11-1.80). When compared to living with family, the hypertension risk was increased in the first quartile of living alone time (0-6.1 years) (HR: 1.76; 95% CI 1.16-2.66), the second quartile (6.1-10.6 years) (HR: 1.56; 95% CI 1.07-2.29), and the third quartile (10.6-19.3 years) (HR: 1.66; 95% CI 1.08-2.55). Surprisingly, no significant association was found in the fourth quartile (≥19.3 years) with hypertension risk. Stratified and Interaction analyses indicated no significant interaction effects between subgroups. Sensitivity analyses yielded consistent results.

Conclusion

Living alone was independently associated with an increased risk of hypertension in older men. The highest risk was found in those with the least time alone. These findings imply that social isolation and lack of companionship could be pivotal in hypertension development. Furthermore, the study highlights the need to consider living alone duration when assessing its impact on health outcomes.