Social Activities and Risk of Dementia in Community-Dwelling Older People: Gender-Specific Findings From a Prospective Cohort Study

OBJECTIVES

This study examines the gender-specific associations between a wide range of social activities and dementia risk.

METHODS

A prospective cohort study was conducted involving community-dwelling older Australians (≥70 years) without significant cognitive impairment at enrolment. During the first year of enrolment, we assessed 25 self-reported social activities covering various aspects, including support from relatives and friends, community participation, social interactions with surroundings, and loneliness. Dementia diagnosis followed DSM-IV criteria, adjudicated by an international expert panel. To estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations between social activities and dementia, we performed Cox proportional hazards models, adjusting for age, educational attainment, baseline global cognition, and depressive symptoms.

RESULTS

Among 9,936 participants who completed all social activity questionnaires (median [IQR] age: 73.4 [71.6-77.1] years; 47.4% men), dementia was diagnosed in 3.8% of men (n = 181/4,705) and 2.6% of women (n = 138/5,231) over a median 6.4 years (IQR: 5.3-7.6, range: 0.2-10.1) follow-up. Gender-specific relationships emerged: caregiving for a person with illness/disability in women (HR: 0.65, 95% CI: 0.42-0.99), and having ≥9 relatives feeling close to call for help in men (HR: 0.56, 95% CI: 0.33-0.96; reference <9 relatives) were associated with reduced dementia risk. Unexpectedly, in women, having ≥5 friends with whom they felt comfortable discussing private matters were associated with a greater dementia risk (HR: 1.69, 95% CI: 1.10-2.59; reference ≤2 friends). Imputed models further identified that babysitting/childminding was associated with lower dementia risk in men (HR: 0.75, 95% CI: 0.56-0.99). No other social activities showed significant associations with dementia.

DISCUSSION

This study provides evidence of social activities influencing dementia risk. Further investigations are required to uncover the mechanisms driving these observed relationships.

Associations of body habitus and its changes with incident dementia in older adults

BACKGROUND

This study examined the associations of body mass index (BMI) and waist circumference (WC), as well as their short- and long-term changes over time, with incident dementia in older individuals.

METHODS

Data came from 18,837 community-dwelling individuals aged 65+ years from Australia and the United States, who were relatively healthy without major cognitive impairment at enrolment. Anthropometric measures were prospectively assessed at baseline, as well as change and variability from baseline to year two (three time-points). In a subgroup (n = 11,176), self-reported weight at age 18 and 70+ years was investigated. Dementia cases satisfied DSM-IV criteria. Cox regression was used to examine the associations between anthropometric measures and incident risk of dementia.

RESULTS

Compared to normal weight, an overweight (HR: 0.67, 95%CI: 0.57-0.79, p < 0.001) or obese BMI (HR: 0.73, 95%CI: 0.60-0.89, p = 0.002), or a larger WC (elevated, HR: 0.71, 95%CI: 0.58-0.86, p < 0.001; highly elevated, HR: 0.65, 95%CI: 0.55-0.78, p < 0.001; relative to low) at baseline was associated with lower dementia risk. In contrast, substantial increases in BMI (>5%) over 2 years after baseline were associated with higher dementia risk (HR: 1.49, 95% CI: 1.17-1.91, p = 0.001). Increased dementia risk was also seen with an underweight BMI at baseline and a 2-year BMI decrease (>5%), but these associations appeared only in the first 4 years of follow-up. Compared to normal weight at both age 18 and 70+ years, being obese at both times was associated with increased dementia risk (HR: 2.27, 95%CI: 1.22-4.24, p = 0.01), while obesity only at age 70+ years was associated with decreased risk (HR: 0.70, 95%CI: 0.51-0.95, p = 0.02).

CONCLUSIONS

Our findings suggest that long-term obesity and weight gain in later life may be risk factors for dementia. Being underweight or having substantial weight loss in old age may be early markers of pre-clinical dementia.

Association Between Triglycerides and Risk of Dementia in Community-Dwelling Older Adults: A Prospective Cohort Study

BACKGROUND AND OBJECTIVES

It has been suggested that higher triglyceride levels were associated with a lower risk of Alzheimer disease. This study aimed to examine the association of triglycerides with dementia and cognition change in community-dwelling older adults.

METHODS

This prospective longitudinal study used data from the Aspirin in Reducing Events in the Elderly (ASPREE) randomized trial of adults aged 65 years or older without dementia or previous cardiovascular events at enrollment. The main outcome was incident dementia. Other outcomes included changes in composite cognition and domain-specific cognition (global cognition, memory, language and executive function, and psychomotor speed). The association between baseline triglycerides and dementia risk was estimated using Cox proportional hazard models adjusting for relevant risk factors. Linear mixed models were used to investigate cognitive change. The analysis was repeated in a subcohort of participants with available APOE-ε4 genetic data with additional adjustment for APOE-ε4 carrier status and an external cohort (UK Biobank) with similar selection criteria applied.

RESULTS

This study included 18,294 ASPREE participants and 68,200 UK Biobank participants (mean age: 75.1 and 66.9 years; female: 56.3% and 52.7%; median [interquartile range] triglyceride: 106 [80-142] mg/dL and 139 [101-193] mg/dL), with dementia recorded in 823 and 2,778 individuals over a median follow-up of 6.4 and 12.5 years, respectively. Higher triglyceride levels were associated with lower dementia risk in the entire ASPREE cohort (hazard ratio [HR] with doubling of triglyceride: 0.82, 95% CI 0.72-0.94). Findings were similar in the subcohort of participants with APOE-ε4 genetic data (n = 13,976) and in the UK Biobank cohort (HR was 0.82 and 0.83, respectively, all p ≤ 0.01). Higher triglycerides were also associated with slower decline in composite cognition and memory over time (p ≤ 0.05).

DISCUSSION

Older adults with higher triglyceride levels within the normal to high-normal range had a lower dementia risk and slower cognitive decline over time compared with individuals with lower triglyceride levels. Higher triglyceride levels may be reflective of better overall health and/or lifestyle behaviors that would protect against dementia development. Future studies are warranted to investigate whether specific components within the total circulating pool of plasma triglycerides may promote better cognitive function, with the hope of informing the development of new preventive strategies.

Lifestyle Enrichment in Later Life and Its Association With Dementia Risk

Importance

Lifestyles enriched with socially and mentally stimulating activities in older age may help build cognitive reserve and reduce dementia risk.

Objective

To investigate the association of leisure activities and social networks with dementia risk among older individuals.

Design, Setting, and Participants

This longitudinal prospective cohort study used population-based data from the ASPREE Longitudinal Study of Older Persons (ALSOP) for March 1, 2010, to November 30, 2020. Community-dwelling individuals in Australia aged 70 years or older who were generally healthy and without major cognitive impairment at enrollment were recruited to the ALSOP study between March 1, 2010, and December 31, 2014. Data were analyzed from December 1, 2022, to March 31, 2023.

Exposures

A total of 19 measures of leisure activities and social networks assessed at baseline were classified using exploratory factor analysis.

Main Outcomes and Measures

Dementia was adjudicated by an international expert panel according to Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria. Cox proportional hazards regression examined dementia risk over 10 years, adjusting for education, socioeconomic status, and a range of health-related factors.

Results

This study included 10 318 participants. Their median age was 73.8 (IQR, 71.6-77.2) years at baseline, more than half (52.6%) were women, and most self-identified as White (98.0%). In adusted analyses, more frequent engagement in adult literacy activities (eg, writing letters or journaling, using a computer, and taking education classes) and in active mental activities (eg, playing games, cards, or chess and doing crosswords or puzzles) was associated with an 11.0% (adjusted hazard ratio [AHR], 0.89 [95% CI, 0.85-0.93]) and a 9.0% (AHR, 0.91 [95% CI, 0.87-0.95]) lower risk of dementia, respectively. To a lesser extent, engagement in creative artistic activities (craftwork, woodwork, or metalwork and painting or drawing) (AHR, 0.93 [95% CI, 0.88-0.99]) and in passive mental activities (reading books, newspapers, or magazines; watching television; and listening to music or the radio) (AHR, 0.93 [95% CI, 0.86-0.99]) was also associated with reduced dementia risk. In contrast, interpersonal networks, social activities, and external outings were not associated with dementia risk in this sample.

Conclusions and Relevance

These results suggest that engagement in adult literacy, creative art, and active and passive mental activities may help reduce dementia risk in late life. In addition, these findings may guide policies for geriatric care and interventions targeting dementia prevention for older adults.

Grip strength, gait speed, and trajectories of cognitive function in community-dwelling older adults: A prospective study

Introduction

This study investigated whether grip strength and gait speed predict cognitive aging trajectories and examined potential sex-specific associations.

Methods

Community-dwelling older adults (n = 19,114) were followed for up to 7 years, with regular assessment of global function, episodic memory, psychomotor speed, and executive function. Group-based multi-trajectory modeling identified joint cognitive trajectories. Multinomial logistic regression examined the association of grip strength and gait speed at baseline with cognitive trajectories.

Results

High performers (14.3%, n = 2298) and low performers (4.0%, n = 642) were compared to the average performers (21.8%, n = 3492). Grip strength and gait speed were positively associated with high performance and negatively with low performance (P-values < 0.01). The association between grip strength and high performance was stronger in women (interaction P < 0.001), while gait speed was a stronger predictor of low performance in men (interaction P < 0.05).

Discussion

Grip strength and gait speed are associated with cognitive trajectories in older age, but with sex differences.

Highlights

There is inter-individual variability in late-life cognitive trajectories.Grip strength and gait speed predicted cognitive trajectories in older age.However, sex-specific associations were identified.In women, grip strength strongly predicted high, compared to average, trajectory.In men, gait speed was a stronger predictor of low cognitive performance trajectory.

Association of covert brain infarcts and white matter hyperintensities with risk of hip fracture in older adults: the Cardiovascular Health Study

Covert brain infarcts and white matter hyperintensities (WMHs), incidental markers of brain microvascular disease commonly seen on brain MRIs in older adults, have been associated with falls and lower bone mineral density. We found covert infarcts and WMHs may also be associated with an increased risk of future hip fracture.

INTRODUCTION

To determine whether covert infarcts and white matter hyperintensities (WMHs) are associated with increased risk of incident hip fracture.

METHODS

A prospective cohort of 3373 community-dwelling adults aged ≥ 65 years enrolled in the Cardiovascular Health Study with a brain MRI (1992-1993) was analyzed. Covert infarcts were categorized by number of infarcts and largest infarct size. WMH burden was assessed by radiologists and graded qualitatively from 0 (no WMHs) to 9 (extensive).

RESULTS

Participants had 465 incident hip fractures during a mean follow-up of 12.8 years. The demographic-adjusted hazard of incident hip fracture was 32% higher among participants with ≥ 1 covert infarct compared to those without infarcts (hazard ratio (HR) 1.32; 95% CI, 1.08-1.62). The hazard of incident hip fracture was similar after further adjustment for medications and medical history (HR = 1.34; 95% CI, 1.08-1.65), but attenuated following additional adjustment for functional status, frailty, and falls (HR = 1.25; 95% CI, 0.99-1.57). Fully adjusted hazard of incident hip fracture per increase in infarct number was 1.10 (95% CI, 0.98-1.23); risk in individuals whose largest infarct was ≥ 20 mm versus 3 to < 20 mm was similar. Compared with WMH grades 0-1, the demographic-adjusted hazard of hip fracture was 1.34 (95% CI, 1.09-1.66) and 1.83 (95% CI, 1.37-2.46), respectively, for WMH grades 2-3 and 4-9. The hazard was similar following adjustment for medications and medical history (grades 2-3: HR = 1.32; 95% CI, 1.05-1.64; grades 4-9: HR = 1.69; 95% CI, 1.23-2.30), but attenuated following additional adjustment for functional status, frailty, and falls (grades 2-3: HR = 1.24; 95% CI, 0.98-1.56; grades 4-9: HR = 1.34; 95% CI, 0.95-1.90).

CONCLUSION

Older, community-dwelling adults with covert infarcts or WMHs may be at increased risk of hip fracture.

Cognitive impairment, perceived medication adherence, and high-risk medication use in patients with reduced kidney function: A cross-sectional analysis

Background and Aims

Reduced estimated glomerular filtration rate (eGFR < 60 ml/min/1.73 m2) is a risk factor for cognitive impairment (CI) and medication nonadherence. However, the association between CI and medication adherence in adults with reduced eGFR has not been adequately examined. Our pragmatic objectives were to assess the cross-sectional relationship between CI and self-reported medication adherence, medication number, and use of potentially high-risk medications among adults with reduced eGFR.

Methods

An observational cohort study of the epidemiology of CI in community-dwelling adults aged 45 years or older with reduced eGFR.

Results

Our analytic cohort consisted of 420 participants (202 with CI; mean age: 69.7 years) with reduced eGFR, at least one prescription medication, and nonmissing medication adherence data. Participants with CI had four times greater unadjusted odds of reporting good medication adherence than participants without CI (self-report of missing medications <4 days/month; odds ratio [OR]: 4.04, 95% confidence interval [CI]:​​​​​ 1.62-10.10). This difference persisted following adjustment for demographic factors and comorbidities (OR: 5.50, 95% CI: 1.86-16.28). Participants with CI were no more likely than participants without CI to report forgetfulness as a reason for missing medication doses. Participants with CI were, on average, taking more total (mean: 13.3 vs. 11.5, median: 12 vs. 11) and more high-risk (mean: 5.0 vs. 4.2, median: 5 vs. 4) medications than those without CI; these differences were attenuated and no longer significant following adjustment for demographics and comorbidities.

Conclusion

Given the well-documented association between CI and medication nonadherence, better self-reported medication adherence among those with CI may represent perceptions of adherence rather than actual adherence. Participants with CI were, on average, taking more total and more high-risk medications than those without CI, suggesting a possible increased risk for adverse drug events. Our results highlight the potential risks of relying on self-reported medication adherence in reduced eGFR patients with CI.

Cognitive Trajectories in Community-Dwelling Older Adults and Incident Dementia, Disability and Death: A 10-Year Longitudinal Study

Objective

The inter-individual variability in cognitive changes may be early indicators of major health events. We aimed to determine whether late-life cognitive trajectories were associated with incident dementia, persistent physical disability and all-cause mortality.

Methods

Data came from a cohort of older community-dwelling individuals aged 70 years or above in Australia and the United States. Global cognition, verbal fluency, episodic memory and psychomotor speed were assessed regularly at up to seven waves between 2010 and 2017. Dementia, disability in activities of daily living, and death were adjudicated between 2017 and 2020. Latent classes of cognitive trajectories over seven years were determined using group-based trajectory modeling. Multivariable logistic regression was used for the prospective associations between cognitive trajectories and these outcomes.

Results

Cognitive trajectories were defined for 16,174 participants (mean age: 78.9 years; 56.7% female) who were alive and without incident dementia or disability by 2017, among which 14,655 participants were included in the association analysis. Between three and five trajectory classes were identified depending on the cognitive test. Cognitive trajectories were strongly associated with the risk of dementia. For example, compared to those in the highest-functioning trajectory, the worst performers of episodic memory had a 37-fold increased risk of dementia (95% CI: 17.23–82.64). The lowest trajectories of both global cognition and episodic memory also predicted increased mortality risk (OR: 1.80, 95% CI: 1.28–2.52; OR: 1.61, 95% CI: 1.09–2.36, respectively), while only slow psychomotor speed was marginally associated with physical disability (OR: 2.39, 95% CI: 0.99–5.77).

Conclusions

In older individuals, cognitive trajectories appear to be early indicators of clinically relevant health outcomes. Systematic cognitive assessments as part of routine geriatric evaluation may facilitate early identification and interventions for those individuals at highest risk.

Benefits and Harms of Prescription Drugs and Supplements for Treatment of Clinical Alzheimer-Type Dementia

BACKGROUND

Effects of drug treatment of clinical Alzheimer-type dementia (CATD) are uncertain.

PURPOSE

To summarize evidence on the effects of prescription drugs and supplements for CATD treatment.

DATA SOURCES

Electronic bibliographic databases (inception to November 2019), ClinicalTrials.gov (to November 2019), and systematic review bibliographies.

STUDY SELECTION

English-language trials of prescription drug and supplement treatment in older adults with CATD that report cognition, function, global measures, behavioral and psychological symptoms of dementia (BPSD), or harms. Minimum treatment was 24 weeks (≥2 weeks for selected BPSD).

DATA EXTRACTION

Studies with low or medium risk of bias (ROB) were analyzed. Two reviewers rated ROB. One reviewer extracted data; another verified extraction accuracy.

DATA SYNTHESIS

Fifty-five studies reporting non-BPSD outcomes (most ≤26 weeks) and 12 reporting BPSD (most ≤12 weeks) were analyzed. Across CATD severity, mostly low-strength evidence suggested that, compared with placebo, cholinesterase inhibitors produced small average improvements in cognition (median standardized mean difference [SMD], 0.30 [range, 0.24 to 0.52]), no difference to small improvement in function (median SMD, 0.19 [range, -0.10 to 0.22]), no difference in the likelihood of at least moderate improvement in global clinical impression (median absolute risk difference, 4% [range, 2% to 4%]), and increased withdrawals due to adverse events. In adults with moderate to severe CATD receiving cholinesterase inhibitors, low- to insufficient-strength evidence suggested that, compared with placebo, add-on memantine inconsistently improved cognition and improved global clinical impression but not function. Evidence was mostly insufficient about prescription drugs for BPSD and about supplements for all outcomes.

LIMITATION

Most drugs had few trials without high ROB, especially for supplements, active drug comparisons, BPSD, and longer trials.

CONCLUSION

Cholinesterase inhibitors and memantine slightly reduced short-term cognitive decline, and cholinesterase inhibitors slightly reduced reported functional decline, but differences versus placebo were of uncertain clinical importance. Evidence was mostly insufficient on drug treatment of BPSD and on supplements for all outcomes.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (PROSPERO: CRD42018117897).