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Objectives: Fear of falling (FoF) is a common problem among older adults. It can lead to reduced quality of life and less physical activity, which increases fall risk. Earlier work has shown that FoF can be a manifestation of executive dysfunction in adults over 50 years, but studies on people over age 75 years are lacking. Executive functions (EFs) are cognitive functions associated with the frontal lobes and the prefrontal cortex. The aim of this study was to assess associations of EFs and FoF among people aged 80 years or older.

Methods: This cross-sectional study was based on data from the Northern Sweden Silver-MONICA study and included 434 participants aged 80 years or older. EFs were assessed with the Frontal Assessment Battery (FAB) and FoF with the Falls Self-Efficacy Scale–International (FES-I). Multivariable linear regression analysis was used to examine associations among EF, FoF, and a comprehensive set of adjustment factors. Pearson correlation analysis was used to evaluate associations of FES-I and the subitems of the FAB.

Results: EFs as measured by FAB were inversely associated with FoF (β = -0.23; 95% confidence interval, -0.42 to -0.03; p = 0.021), even after comprehensive adjustments. The FAB subitems measuring lexical fluency, inhibitory control, sustained attention, self-organization, motor programming, and planning also were inversely associated with FoF.

Conclusions: Lower EF is associated with higher FoF among people aged 80 years or older. This information is important for treating and preventing FoF in this population.

This study explored stress, anxiety, depression, sleep, and somatic ill-health as predictors of burnout symptoms in a general population. The objectives were to identify underlying latent symptom categories of burnout as well as other aspects of mental and somatic health and to examine whether these symptom categories can predict burnout symptoms 3 years later. Longitudinal data with 3-year follow-up time using validated questionnaires from 1722 participants from a general population in northern Sweden were analysed using exploratory factor analysis (EFA) and structural equation modelling (SEM). The EFA showed overlap between instruments and 10 latent categories of symptoms were identified and used as predictors of burnout in SEM analyses. Two SEM models were tested: one unadjusted and the other adjusting for burnout symptoms at baseline. The symptom categories of anxious tension and gastrointestinal problems were the strongest predictors of burnout symptoms 3 years later, in both models. Sleep problems, depressive symptoms, and self-efficacy for coping with stress were also important predictors in the unadjusted model. One important contribution of this study is the identification of the symptom category anxious tension which may well describe the experiential aspect of stress, incorporating feelings of anxiety, tension, and nervousness. The results indicate that anxious tension includes components that predict burnout symptoms. Gastrointestinal problems were also important predictors of burnout symptoms, and more research is needed to explain the mechanisms of these relationships, several possible mechanisms are proposed in this study. The study found burnout symptoms to be stable over time, potentially masking other symptoms. Anxious tension and gastrointestinal symptoms predicted burnout independently of baseline symptoms, whereas sleep problems, depressive symptoms, and low self-efficacy emerged as predictors only when baseline burnout was not adjusted for.

Objectives: Prospective studies suggest that memory deficits are detectable decades before clinical symptoms of dementia emerge. However, individual differences in long-term memory trajectories prior to diagnosis need to be further elucidated. The aim of the current study was to investigate long-term dementia and mortality risk for individuals with different memory trajectory profiles in a well-characterized population-based sample.

Methods: 1062 adults (aged 45–80 years) who were non-demented at baseline were followed over 23–28 years. Dementia and mortality risk were studied for three previously classified episodic memory trajectory groups: maintained high performance (Maintainers; 26%), average decline (Averages; 64%), and accelerated decline (Decliners; 12%), using multistate modeling to characterize individuals’ transitions from an initial non-demented state, possibly to a state of dementia and/or death.

Results: The memory groups showed considerable intergroup variability in memory profiles, starting 10–15 years prior to dementia diagnosis, and prior to death. A strong relationship between memory trajectory group and dementia risk was found. Specifically, Decliners had more than a fourfold risk of developing dementia compared to Averages. In contrast, Maintainers had a 2.6 times decreased dementia risk compared to Averages, and in addition showed no detectable memory decline prior to dementia diagnosis. A similar pattern of association was found for the memory groups and mortality risk, although only among non-demented.

Conclusion: There was a strong relationship between accelerated memory decline and dementia, further supporting the prognostic value of memory decline. The intergroup differences, however, suggest that mechanisms involved in successful memory aging may delay symptom onset.

Background: Growing evidence show that long term exposure to air pollution increases the risk of dementia.

Objective: The aim of this study was to investigate associations between PM_2.5 exposure and dementia in a low exposure area, and to investigate the role of olfaction and the APOE ε4 allele in these associations.

Methods: Data were drawn from the Betula project, a longitudinal study on aging, memory, and dementia in Sweden. Odor identification ability was assessed using the Scandinavian Odor Identification Test (SOIT). Annual mean PM_2.5 concentrations were obtained from a dispersion-model and matched at the participants’ residential address. Proportional hazard regression was used to calculate hazard ratios.

Results: Of 1,846 participants, 348 developed dementia during the 21-year follow-up period. The average annual mean PM2.5 exposure at baseline was 6.77 µg/m³, which is 1.77 µg/m³ above the WHO definition of clean air. In a fully adjusted model (adjusted for age, sex, APOE, SOIT, cardiovascular diseases and risk factors, and education) each 1 µg/m³ difference in annual mean PM_2.5-concentration was associated with a hazard ratio of 1.23 for dementia (95% CI: 1.01–1.50). Analyses stratified by APOE status (ε4 carriers versus non-carriers), and odor identification ability (high versus low), showed associations only for ε4 carriers, and for low performance on odor identification ability.

Conclusion: PM_2.5 was associated with an increased risk of dementia in this low pollution setting. The associations between PM_2.5 and dementia seemed stronger in APOE carriers and those with below average odor identification ability.

The aim of this study was to investigate occupational cognitive complexity of main lifetime occupation in relation to level and 15-year change in episodic memory recall in a sample of older adults (≥ 65 years, n = 780). We used latent growth curve modelling with occupational cognitive complexity (O*NET indicators) as independent variable. Subgroup analyses in a sample of middle-aged (mean: 49.9 years) men (n = 260) were additionally performed to investigate if a general cognitive ability (g) factor at age 18 was predictive of future occupational cognitive complexity and cognitive performance in midlife. For the older sample, a higher level of occupational cognitive complexity was related to a higher level of episodic recall (β = 0.15, p < .001), but the association with rate of change (β = 0.03, p = .64) was not statistically significant. In the middle-aged sample, g at age 18 was both directly (β = 0.19, p = .01) and indirectly (via years of education after age 18, ab = 0.19) predictive of midlife levels of occupational cognitive complexity. Cognitive ability at age 18 was also a direct predictor of midlife episodic recall (β = 0.60, p ≤ 0.001). Critically, entry of the early adult g factor attenuated the association between occupational complexity and cognitive level (from β = 0.21, p = .01 to β = 0.12, p = .14). Overall, our results support a pattern of preserved differentiation from early to late adulthood for individuals with different histories of occupational complexity.

It is widely known that the apolipoprotein E (APOE) ε4 allele imposes a higher risk for Alzheimer's disease (AD). Recent evidence suggests that exposure to air pollution is also a risk factor for AD, and results from a few studies indicate that the effect of air pollution on cognitive function and dementia is stronger in APOE ε4 carriers than in non-carriers. Air pollution and interaction with APOE ε4 on AD risk thus merits further attention. We studied dementia incidence over a 15-year period from the longitudinal Betula study in Northern Sweden. As a marker for long-term exposure to traffic-related air pollution, we used modelled annual mean nitrogen oxide levels at the residential address of the participants at start of follow-up. Nitrogen oxide correlate well with fine particulate air pollution levels in the study area. We had full data on air pollution, incidence of AD and vascular dementia (VaD), APOE ε4 carrier status, and relevant confounding factors for 1,567 participants. As expected, air pollution was rather clearly associated with dementia incidence. However, there was no evidence for a modifying effect by APOE ε4 on the association (p-value for interaction > 0.30 for both total dementia (AD+VaD) and AD). The results from this study do not imply that adverse effects of air pollution on dementia incidence is limited to, or stronger in, APOE ε4 carriers than in the total population.

Objectives: The aim of this nationwide study was to examine the association between age at retirement and dementia risk, with a follow-up period of up to 24 years.

Methods/design: This cohort study comprised Swedish citizens born in 1930 who were alive in the year 1990 (n=63,505). The cohort was followed for incidents of dementia through data provided by the Swedish National Patient Register and the Cause of Death Register. Age at retirement and socioeconomic variables were retrieved from Statistics Sweden.

Results: During the follow-up, 5,181 individuals received a dementia diagnosis. Competing risk regression models, adjusted for sex, education, marital status, occupation, and previous history of cardiovascular diseases, showed that later-than-average retirement age was associated with decreased dementia risk.

Conclusions: The present results supports the idea that individuals who retired at an older age has a decrease risk of dementia. However, as this was an observation study, unmeasured factors, such as premorbid cognitive level and genetic predisposition, may have influenced our findings and remains to be elucidated in future studies.

Individual differences in cognitive performance increase with advancing age, reflecting marked cognitive changes in some individuals along with little or no change in others. Genetic and lifestyle factors are assumed to influence cognitive performance in ageing by affecting the magnitude and extent of age-related brain changes (i.e., brain maintenance or atrophy), as well as the ability to recruit compensatory processes. The purpose of this review is to present findings from the Betula study and other longitudinal studies, with a focus on clarifying the role of key biological and environmental factors assumed to underlie individual differences in brain and cognitive ageing. We discuss the vital importance of sampling, analytic methods, consideration of non-ignorable dropout, and related issues for valid conclusions on factors that influence healthy neurocognitive ageing.

Objectives: To examine the effect of perceived loneliness on the development of dementia (all-cause), Alzheimer's disease (AD), and vascular dementia (VaD).

Method: The study comprised 1,905 nondemented participants at baseline, drawn from the longitudinal Betula study in Sweden, with a follow-up time of up to 20 years (mean 11.1 years). Loneliness was measured with a single question: "Do you often feel lonely?".

Results: During the follow-up, 428 developed dementia; 221 had AD, 157 had VaD, and 50 had dementia of other subtypes. The entire dementia group is denoted "all-cause dementia". Cox regression models, adjusted for age, gender, and a baseline report of perceived loneliness, showed increased risk of all-cause dementia (hazard ratio [HR] = 1.46, 95% confidence interval [CI] 1.14–1.89), and AD (HR = 1.69, 95% CI 1.20–2.37), but not VaD (HR = 1.34, 95% CI 0.87–2.08). After adjusting for a range of potential confounders, and excluding participants with dementia onset within the first 5 years of baseline (to consider the possibility of reverse causality), the increased risk for the development of all-cause dementia and AD still remained significant (HR = 1.51, 95% CI 1.01–2.25 for all-cause dementia; HR = 2.50, 95% CI 1.44–4.36 for AD).

Discussion: The results suggest that perceived loneliness is an important risk factor for all-cause dementia and especially for AD, but not for VaD. These results underscore the importance of paying attention to subjective reports of loneliness among the elderly adults and identifying potential intervention strategies that can reduce loneliness.

High mental demands at work was examined as a possible protective factor to reduce the risk of dementia in 1,277 initially dementia-free participants, aged 60 years and older. The cohort was followed for a mean of 13.6 years. During follow-up, 376 participants developed all-cause dementia (Alzheimer’s disease = 199; vascular dementia = 145). The association between mental demands at work and dementia was analyzed with Cox hazard models, adjusted for a range of covariates. The results revealed no significant association between mental demands at work and incidence of dementia. Based on the measures used in this study, it was concluded that high mental demands at work may not reduce the risk of dementia later on in life.