Are changes in self-rated health associated with memory decline in older adults?

OBJECTIVE: The association between patterns of change in self-rated health (SRH) and memory trajectories in older adults was examined using a systematic approach. METHOD: Data from the Health and Retirement Study (n = 6,016) and the English Longitudinal Study of Ageing (n = 734) were analyzed. Individuals were grouped into five categories according to their pattern of change in SRH over 8 years: stable excellent/very good/good, stable fair/poor, improvement, decline, and fluctuating pattern without a trend. Memory was measured using immediate and delayed recall tests. Kruskal–Wallis, chi-squares tests, and linear mixed models were used to examine the association. RESULTS: Different rates of decline in memory can be identified in the different patterns of change in SRH. Those who had a stable excellent/very good/good pattern had the slowest rate of decline. DISCUSSION: Our findings suggest that SRH status and patterns of change could be used as a marker of cognitive decline in prevention screening programs

Education, occupational class, and cognitive decline in preclinical dementia

We investigated education and occupational influences as markers of cognitive reserve in relation to cognitive performance and decline on multiple fluid and crystallized abilities in preclinical dementia. From the total sample of 702 participants stemming from the OCTO-Twin Study (Sweden), aged 80+ at baseline in 1992-1993, only those who developed dementia during the study period (N = 127) were included in these analyses. Random effects models were used to examine the level of performance at the time of dementia diagnosis and the rates of decline prior to diagnosis. The results demonstrated that both fluid and crystallized abilities decline in preclinical stages, and that education and occupational class have independent moderating roles on the cognitive performance at the time of diagnosis, but not on the rates of decline

An international evaluation of cognitive reserve and memory changes in early old age in ten European countries

BACKGROUND: Cognitive reserve was postulated to explain individual differences in susceptibility to ageing, offering apparent protection to those with higher education. We investigated the association between education and change in memory in early old age. METHODS: Immediate and delayed memory scores from over 10,000 individuals aged 65 years and older, from 10 countries of the Survey of Health, Ageing and Retirement in Europe (SHARE), were modeled as a function of time in the study over an 8-year period, fitting independent latent growth models (LGM). Education was used as a marker of cognitive reserve and evaluated in associations with memory performance and rate of change, while accounting for income, general health, smoking, body mass index (BMI), sex and baseline age. RESULTS: In most countries, more educated individuals performed better on both memory tests at baseline, compared to those less educated. However, education was not protective against faster decline, except for in Spain for both immediate and delayed recall (0.007 (SE=0.003) & 0.006 (SE=0.002), and Switzerland for immediate recall 0.006 (SE=0.003). Interestingly, highly educated Italian respondents had slightly faster declines in immediate recall (-0.006 (SE=0.003)). CONCLUSIONS: We found weak evidence of a protective effect of education on memory change in most European samples, although there was a positive association with memory performance at individuals' baseline assessment

Hierarchy and Speed of Loss in Physical Functioning: A Comparison Across Older U.S. and English Men and Women

Background: We aimed to identify the hierarchy of rates of decline in 16 physical functioning measures in U.S. and English samples, using a systematic and integrative coordinated data analysis approach. Methods: The U.S. sample consisted of 13,612 Health and Retirement Study participants, and the English sample consisted of 5,301 English Longitudinal Study of Ageing participants. Functional loss was ascertained using self-reported difficulties performing 6 activities of daily living and 10 mobility tasks. The variables were standardized, rates of decline were computed, and mean rates of decline were ranked. Mann– Whitney U tests were performed to compare rates of decline between studies. Results: In both studies, the rates of decline followed a similar pattern; difficulty with eating was the activity that showed the slowest decline and climbing several flights of stairs and stooping, kneeling, or crouching the fastest declines. There were statistical differences in the speed of decline in all 16 measures between countries. American women had steeper declines in 10 of the measures than English women. Similar differences were found between American and English men. Conclusions: Reporting difficulties climbing several flights of stairs without resting, and stooping, kneeling, or crouching are the first indicators of functional loss reported in both populations

Gait speed as predictor of transition into cognitive impairment: Findings from three longitudinal studies on aging

Objectives: Very few studies looking at slow gait speed as early marker of cognitive decline investigated the competing risk of death. The current study examines associations between slow gait speed and transitions between cognitive states and death in later life. / Methods: We performed a coordinated analysis of three longitudinal studies with 9 to 25 years of follow-up. Data were used from older adults participating in H70 (Sweden; n = 441; aged ≥70 years), InCHIANTI (Italy; n = 955; aged ≥65 years), and LASA (the Netherlands; n = 2824; aged ≥55 years). Cognitive states were distinguished using the Mini-Mental State Examination. Slow gait speed was defined as the lowest sex-specific quintile at baseline. Multistate models were performed, adjusted for age, sex and education. / Results: Most effect estimates pointed in the same direction, with slow gait speed predicting forward transitions. In two cohort studies, slow gait speed predicted transitioning from mild to severe cognitive impairment (InCHIANTI: HR = 2.08, 95%CI = 1.40–3.07; LASA: HR = 1.33, 95%CI = 1.01–1.75) and transitioning from a cognitively healthy state to death (H70: HR = 3.30, 95%CI = 1.74–6.28; LASA: HR = 1.70, 95%CI = 1.30–2.21). / Conclusions: Screening for slow gait speed may be useful for identifying older adults at risk of adverse outcomes such as cognitive decline and death. However, once in the stage of more advanced cognitive impairment, slow gait speed does not seem to predict transitioning to death anymore

The importance of engaging in physical activity in older adulthood for transitions between cognitive status categories and death: A coordinated analysis of 14 longitudinal studies

Background: Given increasing incidence of cognitive impairment and dementia, further understanding of modifiable factors contributing to increased healthspan is crucial. Extensive literature provides evidence that physical activity (PA) delays the onset of cognitive impairment; however, it is unclear whether engaging in PA in older adulthood is sufficient to influence progression through cognitive status categories. Method: Applying a coordinated analysis approach, this project independently analyzed 14 longitudinal studies (NTotal = 52 039; mean baseline age across studies = 69.9-81.73) from North America and Europe using multistate survival models to estimate the impact of engaging in PA on cognitive status transitions (nonimpaired, mildly impaired, severely impaired) and death. Multinomial regression models were fit to estimate life expectancy (LE) based on American PA recommendations. Meta-analyses provided the pooled effect sizes for the role of PA on each transition and estimated LEs. Results: Controlling for baseline age, sex, education, and chronic conditions, analyses revealed that more PA is significantly associated with decreased risk of transitioning from nonimpaired to mildly impaired cognitive functioning and death, as well as substantially longer LE. Results also provided evidence for a protective effect of PA after onset of cognitive impairment (eg, decreased risk of transitioning from mild-to-severe cognitive impairment; increased likelihood of transitioning backward from severe-to-mild cognitive impairment), though between-study heterogeneity suggests a less robust association. Conclusions: These results yield evidence for the importance of engaging in PA in older adulthood for cognitive health, and a rationale for motivating older adults to engage consistently in PA