Anna Sundström

Subjective memory impairment in older adults predicts future dementia independent of baseline memory performance: Evidence from the Betula prospective cohort study.

The objective was to examine whether subjective memory impairment (SMI) predicts all‐cause dementia or Alzheimers disease (AD) in a population‐based study with long‐term follow‐up (median = 10 years).

Fatigue before and after mild traumatic brain injury: Pre-post-injury comparisons in relation to Apolipoprotein E

Primary objective: To assess the incidence of fatigue for persons following a mild traumatic brain injury (MTBI) and to evaluate the relationship between fatigue and APOE genotype. As fatigue is often found to be influenced by anxiety, depression and sleep disturbance, these factors were also measured. Methods and procedures: Thirty-one persons who sustained a MTBI were drawn from a population-based longitudinal study. Each person who sustained a MTBI was matched by age, gender, education and APOE genotype with two non-head injury controls. Self-reported pre- and post-injury incidence of fatigue, anxiety, depression and sleep disturbance was compared within-group and between groups. Results: For the MTBI group, incidence of fatigue was almost twice as common post- than pre-injury, whereas there was no corresponding change in a non-injured control group. Within the MTBI-group, post-injury fatigue was particularly common for carriers of the APOEϵ4 allele. Conclusions: Fatigue is common sequela after a MTBI and especially pronounced for carriers of the APOEϵ4 allele.

The effects of marital status on episodic and semantic memory in healthy middle-aged and old individuals.

The present study examined the influences of marital status on different episodic and semantic memory tasks. A total of 1882 adult men and women participated in a longitudinal project (Betula) on memory, health and aging. The participants were grouped into two age cohorts, 35-60 and 65-85, and studied over a period of 5 years. Episodic memory tasks concerned recognition and recall, whereas semantic memory tasks concerned knowledge and fluency. The results showed, after controlling for education, some diseases, chronological age and leisure activity as covariates, that there were significant differences between married and single individuals in episodic memory, but not in semantic memory. Married people showed significantly better memory performances than singles in both subsystems of episodic memory, that is, recall and recognition. Also, the rate of decline in episodic memory was significantly larger for singles and widowed than other groups over the 5-year time period in both age groups. The findings demonstrate that the positive relation found between marriage and health can be extended to the relation between marriage and cognitive performance. This effect might be explained by the role played by cognitive stimulation in memory and cognition.

Effects of Perceived Long-Term Stress on Subjective and Objective Aspects of Memory and Cognitive Functioning in a Middle-Aged Population-Based Sample

ABSTRACT The longitudinal effects of perceived stress on measures of memory and two other cognitive functions (word fluency, visuospatial ability) in a middle-aged sample (40–60 years, M age = 47.1 years, SD = 6.1 years; n = 192) were examined. A group describing themselves as stressed in general at baseline, and at follow-up measurement 5 and 10 years later (n = 96) was compared with a matched (age, sex) low-stress group (n = 96). The results revealed more depressive symptoms over time in the high-stress group. With regard to memory, a dissociation between subjective and objective measures was observed. Specifically, participants in the high-stress group rated their memory as worse over time as compared with controls, and reported a higher frequency of occurrence of everyday memory failures, effects partly independent of depressive symptoms. However, the groups did not differ in terms of objective episodic memory performance, word fluency or block design performance, with stable levels of performance over time regardless of perceived stress. The lack of effects of stress on cognitive performance is discussed in the light of factors such as stress level, age of the participants, and other individual difference factors.

Marital status and risk of dementia: a nationwide population-based prospective study from Sweden

Objectives To examine the association between marital status and dementia in a cohort of young-old (50–64) and middle-old (65–74) adults, and also whether this may differ by gender. Design Prospective population-based study with follow-up time of up to 10 years. Setting Swedish national register-based study. Participants 2 288 489 individuals, aged 50–74 years, without prior dementia diagnosis at baseline. Dementia was identified using the Swedish National Patient Register and the Cause of Death Register. Outcome measures The influence of marital status on dementia was analysed using Cox proportional hazards models, adjusted stepwise for multiple covariates (model 1: adjusted for age and gender; and model 2: additionally adjusted for having adult children, education, income and prior cardiovascular disease). Results During follow-up, 31 572 individuals in the study were identified as demented. Cox regression showed each non-married subcategory to be associated with a significantly higher risk of dementia than the married group, with the highest risk observed among people in the young-old age group, especially among those who were divorced or single (HRs 1.79 vs 1.71, fully adjusted model). Analyses stratified by gender showed gender differences in the young-old group, with indications of divorced men having a higher relative risk compared with divorced women (HRs 2.1 vs 1.7, only-age adjusted model). However, in the fully adjusted model, these differences were attenuated and there was no longer any significant difference between male and female participants. Conclusions Our results suggest that those living alone as non-marrieds may be at risk for early-onset and late-onset dementia. Although more research is needed to understand the underlying mechanism by which marital status is associated with dementia, this suggests that social relationships should be taken seriously as a risk factor for dementia and that social-based interventions may provide an opportunity to reduce the overall dementia risk.

The relationship between marital and parental status and the risk of dementia.

BACKGROUND This study examines the association between marital and parental status and their individual and combined effect on risk of dementia diseases in a population-based longitudinal study while controlling for a range of potential confounders, including social networks and exposure to stressful negative life events. METHODS A total of 1,609 participants without dementia, aged 65 years and over, were followed for an average period of 8.6 years (SD = 4.8). During follow-up, 354 participants were diagnosed with dementia. Cox regression was used to investigate the effect of marital and parental status on risk of dementia. RESULTS In univariate Cox regression models (adjusted for age as time scale), widowed (hazard ratio (HR) 1.42, 95% confidence interval (CI) = 1.13-1.78), and not having children (HR 1.54, 95% CI = 1.15-2.06) were significantly associated with incident dementia. In multivariate analyses that included simultaneously marital and parental status and covariates that were found to be significant in univariate models (p < 0.10), the HR was 1.30 (95% CI = 1.01-1.66) for widowed, and 1.51 (95% CI = 1.08-2.10) for those not having children. Finally, a group of four combined factors was constructed: married parents (reference), married without children, widowed parents, and widowed without children. The combined effect revealed a 1.3 times higher risk (95% CI = 1.03-1.76) of dementia in widow parents, and a 2.2 times higher risk (95% CI = 1.36-3.60) in widowed persons without children, in relation to married parents. No significant difference was observed for those being married and without children. CONCLUSIONS Our findings suggest that marital- and parental status are important risk factors for developing dementia, with especially increased risk in those being both widowed and without children.

Cognitive Status in Persons with Amalgam-related Complaints

Self-reported cognitive symptoms are frequent in persons with amalgam-related complaints, but few studies have focused on their cognitive function. The aim was to examine a symptom profile and whether participants with amalgam-related complaints have cognitive deficits in comparison with control individuals. We drew 342 participants with amalgam-related complaints and 342 one-to-one matched control individuals from a longitudinal population-based study. For 81 of the participants with amalgam-related complaints and controls, data were available approximately five years before the onset of complaints, making a longitudinal analysis possible. All participants were assessed by a self-reported health questionnaire and a comprehensive cognitive test battery. The participants with amalgam-related complaints reported more symptoms, mainly musculoskeletal and neuropsychological, compared with control individuals (p < 0.001). The results revealed no significant difference between the amalgam and control group, either cross-sectionally or longitudinally, for any of the cognitive tests. These results suggest that cognitive decline is not associated with amalgam-related complaints.

Stressful negative life events and amalgam-related complaints

OBJECTIVES The role of stressful life events in the onset of self-reported amalgam-related complaints is unclear. The aim of this study was to examine the relationship between life events and amalgam-related complaints. METHOD The participants were selected from a longitudinal population-based study. One-to-one matching of 337 participants with amalgam-related complaints to 337 participants without such complaints was performed. For 81 of the participants with amalgam-related complaints and their matched controls, data was also available approximately 5 years before the onset of complaints, making longitudinal analysis possible. All participants completed questionnaires assessing the occurrence of 55 life events. RESULTS The results showed that many participants with amalgam-related complaints experienced negative life events before and at the onset of amalgam-related complaints. They also reported more unexpected and uncontrollable events difficult to adjust to in comparison with controls. The groups did not differ on positive or neutral life events. Somatic illness or surgical operation was the most common life event. Death of a very close family member and a major change in financial situation were also commonly reported. CONCLUSIONS This study indicates that adverse negative life events could play a vital role in understanding and explaining amalgam-related complaints.

Self-reported memory failures : associations with future dementia in a population-based study with long-term follow-up

To examine the association between self‐reported memory failures and incident dementia in individuals aged 60 and older.

Social relationships and risk of dementia: a population-based study.

BACKGROUND The objective was to examine whether aspects of social relationships in old age are associated with all-cause dementia and Alzheimers disease (AD). METHODS We studied 1,715 older adults (≥ 65 years) who were dementia-free at baseline over a period of up to 16 years. Data on living status, contact/visit frequency, satisfaction with contact frequency, and having/not having a close friend were analyzed using Cox proportional hazards regressions with all-cause dementia or AD as the dependent variable. To control for reverse causality and to identify potential long-term effects, we additionally performed analyses with delayed entry. RESULTS We identified 373 incident cases of dementia (207 with AD) during follow-up. The variable visiting/visits from friends was associated with reduced risk of all-cause dementia. Further, a higher value on the relationships index (sum of all variables) was associated with reduced risk of all-cause dementia and AD. However, in analyses with delayed entry, restricted to participants with a survival time of three years or more, none of the social relationship variables was associated with all-cause dementia or AD. CONCLUSIONS The results indicate that certain aspects of social relationships are associated with incident dementia or AD, but also that these associations may reflect reverse causality. Future studies aimed at identifying other factors of a persons social life that may have the potential to postpone dementia should consider the effects of reverse causality.