How can we best categorize cognitive impairment in nondemented older adults?

Cognitive impairment in public housing residents living in Western New York

PURPOSE

Many older adults in the USA live in public housing facilities and have characteristics that may place them at risk for cognitive impairment. Cognitive impairment has been largely unexamined in this socioeconomically disadvantaged population, however. We therefore aim to characterize its prevalence and correlates, which may help determine which residents could benefit from additional assistance to optimize their ability to function independently.

METHODS

We interviewed 190 English-speaking public housing residents aged 60 years and older in Rochester, a city in Western New York, to assess socio-demographics, mental health, physical health and disability, coping strategies and social support, and service utilization. The Mini-Cog dementia screen evaluated cognitive status.

RESULTS

Twenty-seven percent of residents screened positive for cognitive impairment. In bivariate analyses, older age, less education, greater duration of residence, worse health, less reliance on adaptive coping strategies, and greater utilization of health services were associated with cognitive impairment; age and worse health remained correlated with cognitive impairment in multivariable analyses. Anxiety, depression, and history of substance misuse were not associated with cognitive impairment.

CONCLUSIONS

The high level of cognitive impairment in public housing could threaten residents' continued ability to live independently. Further examination is needed on how such threats to their independence are best accommodated so that public housing residents at risk for needing higher levels of care can successfully age in place.

Risk profiles of subtypes of mild cognitive impairment: the sydney memory and ageing study

OBJECTIVES

To compare the risk profiles of mild cognitive impairment (MCI) subtypes in a population-based elderly sample.

DESIGN

Cross-sectional study.

SETTING

The population-based Sydney Memory and Ageing Study.

PARTICIPANTS

Seven hundred fifty-seven English-speaking, community-dwelling individuals without dementia aged 70 to 90.

MEASUREMENTS

Comprehensive neuropsychological assessments were used to diagnose MCI and its subtypes, categorized as amnestic (aMCI) or nonamnestic (naMCI) and as single- (sdMCI) or multiple- (mdMCI) domain. Risk profiles were derived from sociodemographic; lifestyle; and cardiac, physical, mental, and general health data. Whole-sample and sex-specific comparisons between aMCI and naMCI and between mdMCI and sdMCI were made using age- (and sex-) adjusted multiple regressions comprising initially significant univariate factors.

RESULTS

Risk factors for MCI were presence of the apolipoprotein E (APOE) ε4 allele, heart disease, high homocysteine, poor odor identification ability, low visual acuity, and lower mental activity. The odds of having naMCI rather than aMCI were lower with greater levels of social activity and greater if taking antihypertensives, the latter particularly in men. The odds of naMCI were greater in men taking antidepressants or with a longer 6-meter walk time and in women with hypertension. The odds of having mdMCI rather than sdMCI were greater in participants with a history of depression or having the APOE ε4 allele. Greater odds of mdMCI were also associated with lower mental activity, particularly for women. For men, the odds of mdMCI were greater with the APOE ε4 allele and lower if diagnosed with high cholesterol.

CONCLUSION

MCI subtypes exhibit distinctive, sex-dependent risk profiles. This is consistent with MCI subtypes having different etiologies and outcomes and supports the idea that subtyping MCI may offer predictive validity and clinical application.

Cognitive and memory training in adults at risk of dementia: a systematic review

BACKGROUND

Effective non-pharmacological cognitive interventions to prevent Alzheimer's dementia or slow its progression are an urgent international priority. The aim of this review was to evaluate cognitive training trials in individuals with mild cognitive impairment (MCI), and evaluate the efficacy of training in memory strategies or cognitive exercises to determine if cognitive training could benefit individuals at risk of developing dementia.

METHODS

A systematic review of eligible trials was undertaken, followed by effect size analysis. Cognitive training was differentiated from other cognitive interventions not meeting generally accepted definitions, and included both cognitive exercises and memory strategies.

RESULTS

Ten studies enrolling a total of 305 subjects met criteria for cognitive training in MCI. Only five of the studies were randomized controlled trials. Meta-analysis was not considered appropriate due to the heterogeneity of interventions. Moderate effects on memory outcomes were identified in seven trials. Cognitive exercises (relative effect sizes ranged from .10 to 1.21) may lead to greater benefits than memory strategies (.88 to -1.18) on memory.

CONCLUSIONS

Previous conclusions of a lack of efficacy for cognitive training in MCI may have been influenced by not clearly defining the intervention. Our systematic review found that cognitive exercises can produce moderate-to-large beneficial effects on memory-related outcomes. However, the number of high quality RCTs remains low, and so further trials must be a priority. Several suggestions for the better design of cognitive training trials are provided.