| 1. |
- Pan, Kuan-Yu, et al.
(författare)
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Psychosocial working conditions, trajectories of disability, and the mediating role of cognitive decline and chronic diseases : A population-based cohort study
- 2019
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Ingår i: PLoS Medicine. - : Public Library of Science (PLoS). - 1549-1277 .- 1549-1676. ; 16:9
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Tidskriftsartikel (refereegranskat)abstract
- Background Unfavorable psychosocial working conditions have been associated with cognitive decline and chronic diseases, both of which may subsequently accelerate functional dependence. This study aimed to investigate the association between job demand-control-support combinations and trajectories of disability in later life and to further explore the role of cognitive decline and the co-occurrence of chronic diseases in mediating this association. Methods and findings In this cohort study, 2,937 community dwellers aged 60+ years (mean age 73 +/- 10.6; 62.9% female) residing in the Kungsholmen District of Stockholm, Sweden, participated in the baseline survey (2001-2004) and were followed up to 12 years. Lifelong occupational history was obtained through a standardized interview; job demands, job control, and social support at work in the longest-held occupation were graded with a psychosocial job-exposure matrix. Job control, demands, and social support were dichotomized using the median values from the matrix, respectively, to further generate demand-control-support combinations. Disability was measured by summing the number of impaired basic and instrumental activities of daily living. Global cognitive function was assessed by Mini-Mental State Examination. Chronic conditions were ascertained by clinical examinations, medical history, and patient clinical records; the total number of chronic diseases was summed. Data were analyzed using linear mixed-effects models and mediation analysis. Age, sex, education, alcohol consumption, smoking, leisure activity engagement, early-life socioeconomic status, occupational characteristic and physical demands, and baseline cognitive function and number of chronic diseases were adjusted for in the analyses. Compared with active jobs (high control/high demands; n = 1,807), high strain (low control/high demands; n = 328), low strain (high control/low demands; n = 495), and passive jobs (low control/low demands; n = 307) were all associated with a faster rate of disability progression (beta = 0.07, 95% CI 0.02-0.13, p = 0.01; beta = 0.10, 95% CI 0.06-0.15, p < 0.001; beta = 0.11, 95% CI 0.05-0.18, p < 0.001). The association between high strain and disability progression was only shown in people with low social support at work (beta = 0.13, 95% CI 0.07-0.19, p < 0.001), but not in those with high social support (beta = 0.004, 95% CI -0.09 to 0.10, p = 0.93). Moreover, we estimated that the association between demand-control status and disability trajectories was mediated 38.5% by cognitive decline and 18.4% by accumulation of chronic diseases during the follow-up period. The limitations of this study include unmeasured confounding, self-reported work experience, and the reliance on a psychosocial job-exposure matrix that does not consider variabilities in individuals' perception on working conditions or job characteristics within occupations. Conclusions Our findings suggest that negative psychosocial working conditions during working life may accelerate disability progression in later life. Notably, social support at work may buffer the detrimental effect of high strain on disability progression. Cognitive decline and chronic-disease accumulation, and especially the former, partially mediate the association of psychosocial working conditions with trajectories of disability. Further studies are required to explore more mechanisms that underlie the association between psychosocial working conditions and disability trajectories. Author summaryWhy was this study done? Work is one of the activities that take up a considerable amount of time in our adult lives, thus potentially making it an important determinant of health, even in later life. Inability to independently carry out daily tasks (defined as disability) can affect older people's quality of life and pose a burden on caregivers and societies. A better understanding of the pathway between midlife working conditions and late-life disability may help the development of preventive strategies. What did the researchers do and find? We studied the association of psychosocial working conditions with the rate of disability progression over 12 years in a cohort of 2,937 individuals aged 60 years and older. We found that unfavorable psychosocial working conditions, including high-strain, low-strain, and passive jobs, were related to a faster rate of disability progression. The association of high-strain jobs with accelerated disability accumulation was only present among people with low social support at work. The decrement in cognitive function and increase in chronic-disease burden, and especially the former, partially explained the relationship between unfavorable working conditions and disability progression in later life. What do these findings mean? Unfavorable psychosocial working conditions during working life are related to the progression of disability in later life. Public health authorities, employers, and employees should all be aware of that. Social support at work is especially important in a high-strain work environment given its capacity to attenuate the impact of high-strain jobs on disability accumulation. Monitoring cognitive function and medical conditions of people with unfavorable working conditions is endorsed by the role of both dimensions, and especially of cognitive dysfunction, in accelerating disability progression in older age.
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| 2. |
- Wang, Rui, et al.
(författare)
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Cognitive Reserve : A Life-Course Perspective
- 2023
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Ingår i: Neurobiological and Psychological Aspects of Brain Recovery. - : Springer Publishing Company. - 9783031249303 - 9783031249297 - 9783031249327 ; , s. 121-135
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The concept of reserve has been developed to account for the discontinuity between the extent of brain damage at its clinical manifestation in the form of cognitive decline or dementia. In this chapter, we discuss contributors to cognitive reserve from various stages of the life-course, including childhood, early adulthood, middle age, and late life. Evidence from observational studies as well as intervention trials is presented and assessed. We conclude by arguing that reserve formation in dementia risk is a life-course process whereby baseline cognitive abilities are subjected to modulation by subsequent experiences at diverse stages over the entire life-course. Variations among individuals in their ability to withstand age-related brain changes are ultimately dependent on their life-time accumulation of mental, physical, and lifestyle inputs into cognitive reserve.
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| 3. |
- Dekhtyar, Serhiy, et al.
(författare)
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A life-course study of cognitive reserve in dementia: Dementia incidence in inpatient registers and mmse test scores in a clinical study in sweden
- 2015
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5279 .- 1552-5260. ; 11:7, s. 200-201
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Tidskriftsartikel (refereegranskat)abstract
- Cognitive reserve helps mitigate the impact of pathology on the clinical expression of dementia. Education and occupational complexity are considered as contributors to reserve, although it has been argued that cognitive reserve is likely formed over the life-course. A life-course model of cognitive reserve in dementia risk has not yet been tested. We apply a life-course model and examine if school grades around age 10, formal educational attainment, and lifetime occupational complexity affect dementia incidence in inpatient registers.
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| 4. |
- Dekhtyar, Serhiy, et al.
(författare)
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Association Between Speed of Multimorbidity Accumulation in Old Age and Life Experiences : A Cohort Study
- 2019
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 188:9, s. 1627-1636
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Tidskriftsartikel (refereegranskat)abstract
- Rapidly accumulating multiple chronic conditions (multimorbidity) during aging are associated with many adverse outcomes. We explored the association between 4 experiences throughout life-childhood socioeconomic circumstances, early-adulthood education, midlife occupational stress, and late-life social network-and the speed of chronic disease accumulation. We followed 2,589 individuals aged >= 60 years from the Swedish National Study on Aging and Care in Kungsholmen for 9 years (2001-2013). Information on life experiences was collected from detailed life-history interviews. Speed of disease accumulation was operationalized as the change in the count of chronic conditions obtained from clinical examinations, medical histories, laboratory data, drug use, and register linkages over 9 years. Linear mixed models were used to analyze the data. Speed of disease accumulation was lower in individuals with more than elementary education (for secondary, beta x time = -0.065, 95% CI: -0.126, -0.004; for university, beta x time = -0.118, 95% CI: -0.185, -0.050); for active occupations compared with high-strain jobs (beta x time = -0.078, 95% CI: -0.138, -0.017); and for richer social networks (for moderate tertile, beta x time = -0.102, 95% CI: -0.149, -0.055; for highest tertile, beta x time = -0.135, 95% CI: -0.182, -0.088). The association between childhood circumstances and speed of disease accumulation was attenuated by later-life experiences. Diverse experiences throughout life might decelerate chronic disease accumulation during aging.
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| 5. |
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| 6. |
- Dekhtyar, Serhiy, et al.
(författare)
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Associations of head circumference at birth with earlylife school performance and later-life occupational prestige
- 2015
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Ingår i: Longitudinal and Life Course Studies. - : Bristol University Press. - 1757-9597. ; 6:1, s. 26-42
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Tidskriftsartikel (refereegranskat)abstract
- Head circumference at birth has been suggested as a marker of foetal brain development. New-borns with small head size have been shown to have lower intelligence scores in childhood. It is, however, unclear whether this relationship extends into adult life, and more importantly, whether adult status attainment and lifetime success is affected as a result. Furthermore it is unclear how social origin at birth attenuates the relationship between foetal brain development, childhood cognitive outcomes, and lifetime status attainment. Using the Uppsala Birth Cohort Multigenerational Study, a unique population-based database of 14,192 individuals followed from birth into advanced old age, we demonstrate that those born with small head circumference experience reductions in both early-life school performance and lifetime occupational prestige. These effects are not subject to modification by parental social class: small head size at birth is associated with lower grades and lower occupational prestige among individuals born into both advantaged and disadvantaged social classes. Employing causal mediation analysis, we also demonstrate that the link between head circumference at birth and adult occupational prestige is mainly the result of a direct effect, although a portion of this effect is also mediated by early-life school performance which also contributes to occupational attainment trajectories. These findings demonstrate the importance of early-life environments for cognitive development as well as lifetime status attainment.
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| 7. |
- Dekhtyar, Serhiy, et al.
(författare)
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Childhood school performance, education and occupational complexity : a life-course study of dementia in the Kungsholmen Project
- 2016
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 45:4, s. 1207-1215
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cognitive reserve hypothesis predicts that intellectually demanding activities over the life course protect against dementia. We investigate if childhood school performance remains associated with dementia once education and occupational complexity are taken into account. Methods: A cohort of 440 individuals aged 75+ from the Kungsholmen Project was followed up for 9 years to detect dementia. To measure early-life contributors to reserve, we used grades at age 9-10 extracted from the school archives. Data on formal education and occupational complexity were collected at baseline and first follow-up. Dementia was ascertained through comprehensive clinical examination. Cox models estimated the relationship between life-course cognitive reserve measures and dementia. Results: Dementia risk was elevated [hazard ratio (HR): 1.54, 95% confidence interval (CI): 1.03 to 2.29] in individuals with low early-life school grades after adjustment for formal educational attainment and occupational complexity. Secondary education was associated with a lower risk of dementia (HR: 0.72, 95% CI: 0.50 to 1.03), although the effects of post-secondary and university degrees were indistinguishable from baseline. Occupational complexity with data and things was not related to dementia. However, an association was found between high occupational complexity with people and dementia, albeit only in women (HR: 0.39, 95% CI: 0.14 to 0.99). The pattern of results remained unchanged after adjustment for genetic susceptibility, comorbidities and depressive symptoms. Conclusion: Low early-life school performance is associated with an elevated risk of dementia, independent of subsequent educational and occupational attainment.
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| 8. |
- Dekhtyar, Serhiy, et al.
(författare)
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Genetic risk of dementia mitigated by cognitive reserve : A cohort study
- 2019
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Ingår i: Annals of Neurology. - : Wiley. - 0364-5134 .- 1531-8249. ; 86:1, s. 68-78
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Tidskriftsartikel (refereegranskat)abstract
- Objective We investigated whether cognitive reserve modifies the risk of dementia attributable to apolipoprotein epsilon 4 (APOE-epsilon 4), a well-known genetic risk factor for dementia. Methods We followed 2,556 cognitively intact participants aged >= 60 years from the ongoing prospective community-based Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). Dementia was ascertained through clinical and neuropsychological assessments and diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria. Structural equation modeling was used to generate a cognitive reserve indicator from 4 previously validated contributors: early life education, midlife substantive work complexity, late life leisure activities, and late life social networks. Cox proportional hazard models estimated dementia risk in relation to cognitive reserve indicator. The interaction between the cognitive reserve indicator and APOE-epsilon 4 was assessed on multiplicative and additive scales. Results After an average of 6.3 years (range = 2.1-10.7) of follow-up, 232 dementia cases were ascertained. Relative to individuals in the lowest tertile of cognitive reserve indicator, those with moderate and high reserve were at a reduced risk of dementia. There was no multiplicative interaction between APOE-epsilon 4 status and cognitive reserve indicator (p = 0.113). Additive interaction was statistically significant. Relative to APOE-epsilon 4 carriers with low cognitive reserve, epsilon 4 carriers with high reserve had a reduced risk of dementia (hazard ratio [HR] = 0.28, 95% confidence interval [CI] = 0.13-0.59). The magnitude of risk reduction was similar in epsilon 4 noncarriers with a high cognitive reserve indicator (HR = 0.24, 95% CI = 0.15-0.40). Interpretation Lifelong engagement in reserve-enhancing activities attenuates the risk of dementia attributable to APOE-epsilon 4. Promoting cognitive reserve might be especially effective in subpopulations with high genetic risk of dementia. ANN NEUROL 2019
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| 9. |
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| 10. |
- Marseglia, Anna, et al.
(författare)
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Social Health and Cognitive Change in Old Age : Role of Brain Reserve
- 2023
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Ingår i: Annals of Neurology. - : John Wiley & Sons. - 0364-5134 .- 1531-8249. ; 93:4, s. 844-855
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Individual aspects of social health (SH; eg, network, engagement, support) have been linked to cognitive health. However, their combined effect and the role of the structural properties of the brain (brain reserve [BR]) remain unclear. We investigated the interplay of SH and BR on cognitive change in older adults.Methods: Within the Swedish National Study on Aging and Care–Kungsholmen, 368 dementia-free adults aged ≥60 years with baseline brain magnetic resonance imaging were followed over 12 years to assess cognitive change. A measure of global cognition was computed at each of the 5 waves of assessment by averaging domain-specific Z scores for episodic memory, perceptual speed, semantic memory, and letter and category fluency. An SH composite score was computed at baseline by combining leisure activities and social network. BR was proxied by total brain tissue volume (TBTV). Linear mixed models (adjusted for sociodemographic, vascular, and genetic factors) were used to estimate cognitive trajectories in relation to SH and TBTV. Interaction analysis and stratification were used to examine the interplay between SH and TBTV.Results: Moderate–good SH (n = 245; vs poor, β-slope = 0.01, 95% confidence interval [CI] = 0.002–0.02, p = 0.018) and moderate-to-large TBTV (n = 245; vs small, β-slope = 0.03, 95% CI = 0.02–0.04, p < 0.001) were separately associated with slower cognitive decline. In stratified analysis, moderate–good SH was associated with higher cognitive levels (but not change) only in participants with moderate-to-large TBTV (β-intercept = 0.21, 95% CI = 0.06–0.37, p < 0.01; interaction SH * TBTV, p < 0.05).Interpretation: Our findings highlight the interplay between SH and BR that likely unfolds throughout the entire life course to shape old-age cognitive outcomes. ANN NEUROL 2023
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