| 1. |
- Hassing, Linda, 1967, et al.
(författare)
-
Overweight in midlife and risk of dementia: a 40-year follow-up study
- 2009
-
Ingår i: International Journal of Obesity. - : Springer. ; 33:8, s. 893-898
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: This study examines whether overweight in midlife increases dementia risk later in life. Methods: In 1963 body mass index was assessed in 1152 participants of The Swedish Twin Registry, at the age of 45–65 years. These participants were later screened for dementia in a prospective study with up to 40 years follow-up. A total of 312 participants were diagnosed with dementia. Results: Logistic regression analyses adjusted for demographic factors, smoking and alcohol habits, indicated that men and women categorized as overweight in their midlife had an elevated risk of dementia (OR=1.59; 95% CI: 1.21–2.07, P=0.002), Alzheimer's disease (OR=1.71; 95% CI: 1.24–2.35, P=0.003), and vascular dementia (OR=1.55; 95% CI: 0.98–2.47, P=0.059). Further adjustments for diabetes and vascular diseases did not substantially affect the associations, except for vascular dementia (OR=1.36; 95% CI: 0.82–2.56, P=0.116), reflecting the significance of diabetes and vascular diseases in the etiology of vascular dementia. There was no significant interaction between overweight and APOE alt epsilon4 status, indicating that having both risk factors does not have a multiplicative effect with regard to dementia risk. Conclusions: This study gives further support to the notion that overweight in midlife increases later risk of dementia. The risk is increased for both Alzheimer's disease and vascular dementia, and follows the same pattern for men and women. Keywords: BMI, alzheimer's disease, vascular dementia, dementia, overweight, obesity
|
|
| 2. |
- Johansson, Boo, et al.
(författare)
-
Cognitive abilities in late life, proximity to death and distance from birth
- 2006
-
Ingår i: Cognitive abilities in late life, proximity to death and distance from birth. Paper presented at the 18th Nordic Congress in Gerontology, Jyväskylä, Finland..
-
Konferensbidrag (refereegranskat)abstract
- Intra-individual change and continuity in cognitive abilities were examined as a conditional function of distance from birth (chronological age) and death in two Swedish population-based samples drawn from the H70 (70+; age-homogenous design) and the OCTO Twin (80+; age-heterogeneous design) studies. Examined cognitive domains included mental speed, memory, fluid, and crystallized abilities Three alternative time-based modelling approaches were used to fit the data a) an age-related approach b) a time-to–death-related approach, and c) a dual time structure component ap-proach including both age- and death-related time components. The death-related time structure accounts better for the data and age-related changes were largely attenuated when accounting for death-related changes, but death-related changes were relatively unaffected by the age-related sources of variance. The results emphasize that the reliance on age as a basic time structure in cognitive aging re-search can be doubtful and the importance of identifying diseases, co-morbidity and other health-related factors that account for cognitive decline in later life. Future studies need to identify and evaluate more specifically the time-related processes that increase the likelihood of death and produce decline in brain and cognitive functioning in later life.
|
|
| 3. |
- Piccinin, M, et al.
(författare)
-
Cross-national coordinated analysis (IALSA) of age, sex, and education effects on change in MMSE scores
- 2006
-
Ingår i: 59th Annual Scientific Meeting of the Gerontological Society of America, Dallas, TX, USA..
-
Konferensbidrag (refereegranskat)abstract
- In a cross-national, multi-study (ALSA, CLS, H-70, HOPE, NAS, OCTO-Twin, LASA) analysis, we systematically address concerns regarding the effect of educational attainment on Mini-Mental Status Exam (MMSE) scores in a descriptive comparison of between-person dif-ferences and within-person age changes. We describe the coordinated analysis process and the first results from the IALSA network. Marked country and birth cohort differences in educa-tional attainment required a flexible modeling approach: median years in school ranged from 6 in LASA and the older Swedish cohorts to 12 in CLS and NAS. For studies with similarly coded education, higher educated participants scored higher and showed less decline. Ignoring the impact of declining health, on average, at age 80, men with six years of education scored between 25 and 27 on the MMSE and declined about 0.3 points per year. Older individuals tend to score lower and decline at a faster rate. Gender differences were mixed.
|
|
| 4. |
- Sacuiu, Simona, 1971, et al.
(författare)
-
Cognitive performance 10-18 years before stroke
- 2005
-
Ingår i: Second Congress of the International Society for Vascular, Behavioural, and Cognitive Disorders (VasCog), Firenze, Italy..
-
Konferensbidrag (refereegranskat)
|
|
| 5. |
- Sacuiu, Simona, 1971, et al.
(författare)
-
The pattern of cognitive symptoms predicts time to dementia onset.
- 2009
-
Ingår i: Alzheimer's & dementia : the journal of the Alzheimer's Association. - : Wiley. - 1552-5279 .- 1552-5260. ; 5:3, s. 199-206
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Few studies have examined whether cognitive symptom patterns differ by age and length of time before dementia onset. Our objective was to investigate whether different patterns of cognitive symptoms at ages 70, 75, and 79 years predict short-term (< or =5 years) and long-term (>5 years) dementia onset. METHODS: A representative sample of 382 nondemented 70-year-olds from Gothenburg, Sweden was examined periodically up to age 90 years. Information on dementia in those lost to follow-up was obtained from medical records. Cognitive assessments at ages 70, 75, and 79 years included psychiatric and psychometric examinations. Four patterns of cognitive performance were examined in relation to dementia onset: (1) unimpaired cognition, (2) isolated low memory, (3) low non-memory, and (4) global low cognitive performance. RESULTS: Short-term onset was predicted by global low performance at ages 70, 75, and 79 years and by low non-memory performance at ages 70 and 75. Isolated low memory was not a short-term predictor at any examination, but it predicted long-term onset at ages 70 and 75 years. CONCLUSIONS: A global pattern of low cognitive performance predicts short-term but not long-term onset of dementia, whereas isolated low memory performance predicts dementia only in the long-term. Our findings also suggest that preclinical symptoms of dementia might differ by age.
|
|
| 6. |
- Thorvaldsson, Valgeir, 1976, et al.
(författare)
-
Age- and time-to death-based interrelationships between perceptual speed and memory in the oldest-old
- 2005
-
Ingår i: The 58th Scientific Meeting with the American Gerontological Society.
-
Konferensbidrag (refereegranskat)abstract
- In this study interrelationships between changes in memory and perceptual speed were examined, across ages 85 to 99, in the Swedish population-based panel study (Gothenburg H-70). Bivariate extensions of the random coefficients model were evaluated by fitting both age- and time-to-death-based models. The findings indicated a significant difference in the nature of age- and time-to-death-based changes. Correlations between performance status at age 85 and time of death was high (.74 and .79 respectively). The age-based between-person correlation was high (.86) but attenuated in the time-to-death-based model (.59). Coupled changes in both models were significant but low (.15 and .18), probably reflecting long inter-measurements intervals and attrition due to death. These findings indicate the importance of modelling cognitive changes within a theoretically directed time structure. Aggregation of health heterogeneous age samples will influence inferences of within-person changes and interrelationship between changes
|
|
| 7. |
- Thorvaldsson, Valgeir, 1976, et al.
(författare)
-
Aging and Late Life Terminal Decline in Perceptual Speed: A Comparison of Alternative Modelling Approaches
- 2006
-
Ingår i: European Psychologist. - : Hogrefe Publishing Group. - 1016-9040 .- 1878-531X. ; 11:3, s. 196-203
-
Tidskriftsartikel (refereegranskat)abstract
- Individual changes in perceptual speed were modelled as a conditional function of age and time-to-death. Alternative time-structured models were evaluated in a Swedish population-based, age-homogeneous sample (Gothenburg H70; N = 764) of individuals assessed at ages 70, 75, 79, 85, 88, 90, 92, 95, 97, and 99. Modelling time as proximity to death accounted bet-ter for the heterogeneity of individual changes than an age-based time structure. Time-to-death was a significant predictor of individual differences in rates of change in the age-based model but age did not significantly predict individual differences in rates of change in model structured by proximity to death. In both the age-based and death-based time-structured mod-els, accelerated changes prior to time of death were observed and provide support for the ter-minal decline hypothesis. Identification of health-related factors and other sources of causal heterogeneity of aging-related change can make productive use of alternative time specifica-tions that emphasize congruency between within-person change processes and aggregate population change
|
|
| 8. |
- Thorvaldsson, Valgeir, 1976
(författare)
-
Change and variability in cognitive performance in old age. Effects of retest, terminal decline, and pre-clinical dementia.
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The focus of the presented studies was to provide population estimates of change and variability in cognitive performance in old age. Data was drawn from the Gerontological and Geriatric Population Studies in Gothenburg, Sweden (H70). In study I retest effects were evaluated on level of performance in five cognitive abilities. In 1971, the total population of 70-years-olds, living in the city of Gothenburg was identified. One-third of them were invited to participate in the study with repeated measurements at ages 70, 75, 79, 81, 85, 88, 90, 92, 95, 97, 99, and 100. In 1985, the remaining survivors of the two-thirds, not invited at baseline, were invited, with measurements at ages 85, 88, 90, 92, 95, 97, 99 and 100. This design allows evaluation of retest effects at age 85. Comparisons revealed a trend toward retest effects on two tests. The study demonstrates how a design-based approach can provide valuable insights into continuous learning processes embedded in population average aging trajectories not confounded with cohort and mortality-related selective attrition. In study II the hypothesis of terminal decline was tested in perceptual speed. Terminal decline refers to acceleration in cognitive decline preceding death. Several growth models were fit to the data (N = 764) that varied in the specification of time. Time to death accounted better for the data as compared with chronological age and there was a substantial acceleration in decline preceding death. Age of death was a significant moderator of between-person differences on age-related change but not on death-related change. The results indicate, 1) support for the terminal decline hypotheses, 2) mortality selection over time, and 3) that terminal decline occurs across ages. In study III onset and rate of terminal decline on cognitive abilities were identified. A death-related change-point modeling procedure, including an automated piecewise linear approach, were fit to the data (N = 288 non-demented). A profile likelihood method was used to draw inferences of the change points. The results indicate onset of terminal decline 6.6 years before death for verbal ability, 7.8 years for spatial ability, and 14.8 years for perceptual speed. Substantial acceleration in cognitive decline is present many years prior to death among non-demented individuals. Time of onset and rate of terminal decline however varies across cognitive abilities. In study IV onset and rate of acceleration in cognitive decline preceding diagnosis of dementia was identified. A pre-clinical-dementia change-point modeling procedure was fit to the data (N = 113 cases and 272 non-cases). The results indicate onset of pre-clinical decline 5.8 years before diagnosis for verbal ability, 9.0 years for spatial ability, and 11.5 years for perceptual speed. Cognitive decline preceding diagnosis of dementia can be discerned from normal aging many years prior to clinical diagnosis. Overall, the findings suggest integration of terminal decline, pre-clinical dementia, and subsequent population composition changes in analyses of change and variability in cognitive performance in old age.
|
|
| 9. |
|
|
| 10. |
- Thorvaldsson, Valgeir, 1976, et al.
(författare)
-
Effects of repeated testing in a longitudinal age-homogeneous study of cognitive aging
- 2006
-
Ingår i: Journal of Gerontology: Psychological Sciences. ; , s. 348-354
-
Tidskriftsartikel (refereegranskat)abstract
- Estimates of gains related to repeated test exposure (retest effects) and within-person cogni-tive changes are confounded in most longitudinal studies because of the nonindependent time structures underlying both processes. Recently developed statistical approaches rely on be-tween-person age differences to estimate effects of repeated testing. This study, however, demonstrates how retest effects can be evaluated at the group level in an age-homogeneous population-based study by use of a sampling-based design approach in which level and change of cognitive performance of previous participants, measured at ages 70, 75, 79, 81, 85, 88, 90, 92, 95, 97, and 99 years, were compared with performances of survivors of a rep-resentative sample identified and drawn from the same original population cohort but invited for the first time at age 85 with subsequent measurements at ages 88, 90, 92, 95, 97, and 99. The comparisons revealed a trend toward retest effects on two out of five cognitive meas-urements. The study demonstrates how a design-based approach can provide valuable in-sights into continuous learning processes embedded in population average aging trajectories that are not confounded with cohort and mortality-related selective attrition
|
|
| 11. |
- Thorvaldsson, Valgeir, 1976, et al.
(författare)
-
Estimating the effects of repeated test exposure by a design-based sampling approach
- 2006
-
Ingår i: The 2006 Cognitive Aging Conference, Atlanta, GA, USA..
-
Konferensbidrag (refereegranskat)abstract
- Estimates of gains related to repeated test exposure and aging-related within-person cognitive changes are confounded in most longitudinal studies because of the nonindependent time structures underlying both processes. Statistical approaches for estimating separate retest effects rely on between-person age differences to estimate effects of repeated testing. This study demonstrates how retest effects can be evaluated at the group-level using a sampling-based design approach where level and change of cognitive performance of previous participants in an age-homogeneous population-based study, measurement at ages 70, 75, 79, 81, 85, 88, 90, 92, 95, 97, and 99, were compared with performances of survivors of a representative sample identified and drawn from of the same original population cohort but invited from the first time at age 85 with subsequent measurements at age 88, 90, 92, 95, 97, and 99. The comparisons revealed a small trend toward retest effects on most of the cognitive measurements. The study demonstrates how a design-based approach can provide valuable insights into continuous learning processes embedded in population average aging trajectories that are not confounded with cohort and mortality-related selective attrition. Implicit assumptions of both statistical and design-based approaches are discussed.
|
|
| 12. |
|
|
| 13. |
- Thorvaldsson, Valgeir, 1976, et al.
(författare)
-
Onset of cognitive decline in pre-clinical dementia: Findings from the longitudinal H-70 study in Göteborg
- 2007
-
Ingår i: XI Congress of the International Federation of Psychiatric Epidemiology, Göteborg, Sweden (abstract nr. OR-19.4)..
-
Konferensbidrag (refereegranskat)abstract
- Background/Objective: To identify an average time of onset when pathological pre-clinical dementia changes occur and can be differentiated from normal cognitive aging changes. Method: Mixed linear models with varying change-points were fit to the cognitive test data from the population-based age-homogeneous sample drawn from the Gerontological and Geriatric Population Studies in Göteborg, Sweden (H70). The analyses included an initial examination at age 70 and multiple subsequent follow-ups until diagnosis of dementia or death. A profile likelihood method was used to determine average change-points based on intra-individual analyses and independent of performance level of the respective cognitive test. Results: Varying but significant change points were identified on all tests indicating different influences of pathological and normal changes across various cognitive abilities. Conclusions: Cognitive decline preceding diagnosis of dementia can be discerned from normal cognitive aging changes years prior to time of a clinical diagnosis.
|
|
| 14. |
- Thorvaldsson, Valgeir, 1976, et al.
(författare)
-
Onset of terminal decline in cognitive abilities in individuals without dementia.
- 2008
-
Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 1526-632X .- 0028-3878. ; 71:12, s. 882-7
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To identify time of onset and rate of mortality-related change (terminal decline) in cognitive abilities in later life. METHOD: The sample consisted of 288 individuals without dementia (born 1901-1902) drawn from the population of Göteborg, Sweden. Participants were followed from age 70 until death, with up to 12 measurement occasions on three cognitive abilities. Change-point analysis was performed using an automated piecewise linear mixed modeling approach to identify the inflection point indicating accelerated within-person change related to mortality. A profile likelihood method was used to identify the change point that best fit the data for each of three cognitive abilities. RESULTS: Onset of terminal decline was identified 6.6 years prior to death for verbal ability, 7.8 years for spatial ability, and 14.8 years for perceptual speed. CONCLUSIONS: There is substantial acceleration in cognitive decline many years prior to death among individuals without dementia. Time of onset and rate of terminal decline vary considerably across cognitive abilities.
|
|
| 15. |
- Thorvaldsson, Valgeir, 1976, et al.
(författare)
-
Time of Onset in Acceleration of Cognitive Decline in Pre-Clinical Dementia. A Report from the H70 Study
- 2007
-
Ingår i: At the 60th Annual Scientific Meeting “The Era of Global Aging: Challenges and Opportunities”. The Gerontologist, vol 47, Spical issue II, Oct. 2007.
-
Konferensbidrag (refereegranskat)abstract
- The main objectives of this study were to describe change in cognitive function prior to diagnoses of dementia. We fit a sequence of mixed linear models with a varying change-point to data drawn from the Gerontological and Geriatric Population Studies in Gothenburg, Sweden (non-cases =272, cases =113). Initial examination was at age 70 with subsequent follow-ups at ages 75, 79, 81, 85, 88, 90, 92, 95, 97, and 99, or until diagnosis or death. A profile likelihood method was used to select the best fitting models and make inferences of the change points. The results demonstrate cross-domain variation in average time of onset of acceleration in decline as well as differences in rate of change prior and post the change point. Cognitive decline preceding diagnosis of dementia can be discerned from normal aging many years prior to clinical diagnosis.
|
|
