| 221. |
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| 222. |
- Thorvaldsson, Valgeir, 1976, et al.
(författare)
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Time of Onset in Acceleration of Cognitive Decline in Pre-Clinical Dementia. A Report from the H70 Study
- 2007
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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.
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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.
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| 223. |
- van den Kommer, Tessa N, et al.
(författare)
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Classification models for early identification of persons at risk for dementia in primary care: an evaluation in a sample aged 80 years and older.
- 2009
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 28:6, s. 567-577
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To evaluate previously developed classification models to make implementation in primary care possible and aid early identification of persons at risk for dementia. METHODS: Data were drawn from the OCTO-Twin study. At baseline, 521 persons >or= 80 years of age were nondemented, and for 387 a blood sample was available. Predictors of dementia were collected and analyzed in initially nondemented persons using generalized estimating equations and Cox survival analyses. RESULTS: In the basic model using predictors already known or easily obtained (basic set), the mean 2-year predictive value increased from 6.9 to 28.8% in persons with memory complaints and an MMSE score
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| 224. |
- Vasilopoulos, T, et al.
(författare)
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Genetic Covaration of Grip Strength and General Cognitive Ability in Octogenarian Swedish Twins
- 2007
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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.. ; , s. 465-
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Konferensbidrag (refereegranskat)abstract
- Grip strength is a strong predictor of later-life disability, morbidity and mortality. Likewise, reduced grip strength has been associated with cognitive decline. Using quantitative genetic techniques, we surveyed the contribution of genetic and environmental factors to the relationship between grip strength and general cognitive ability in 100 monozygotic and 131 dizygotic twin pairs. The sample was selected from the longitudinal study, “Origins of Variance in the Old-Old.” For the analysis, a latent general cognitive ability factor was constructed using measures of verbal ability, spatial ability, speed of processing, and memory. Bivariate model fitting revealed that genetic factors accounted for 74% of the phenotypic correlation ( r = .47) between grip strength and general cognitive ability. These results suggest that shared genetic factors underlie the relationship between grip strength and general cognitive ability and may also support the theory that common factors contribute to overall age-related deterioration of cognitive and non-cognitive functioning. Supported by grants from the National Institute on Aging at the National Institutes of Health (AG08861 and AG000276)
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| 225. |
- Vasilopoulos, Terrie, et al.
(författare)
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Stability of genetic influences on pulmonary function in a longitudinal study of octogenarian twins.
- 2010
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Ingår i: American journal of human biology : the official journal of the Human Biology Council. - : Wiley. - 1520-6300 .- 1042-0533. ; 22:3, s. 375-7
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Tidskriftsartikel (refereegranskat)abstract
- Using data from the first four waves of the OCTO-Twin study (twins 80 + years), the present study investigated the stability and change of genetic and environmental contributions to pulmonary function. Using a genetic simplex model, variance in peak expiratory flow (PEF) at each wave was decomposed into additive genetic and nonshared (specific) environmental factors. Additionally, this analysis distinguished the source of these influences, either from previous waves (transmissions) or from novel influences at each wave (innovations). At each time point (except wave 1), the genetic variance was due to genetic transmissions from prior time points. Conversely, the specific environmental variance in PEF at each time point was mainly due to environmental innovations. These results imply that genetic factors contribute to the stability of pulmonary function over time whereas environmental factors contribute to its change.
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| 226. |
- Watermyer, Tamlyn, et al.
(författare)
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Cognitive Dispersion Predicts Grip Strength Trajectories in Men but not Women in a Sample of the Oldest Old Without Dementia
- 2021
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Ingår i: Innovation in Aging. - : Oxford University Press (OUP). - 2399-5300. ; 5:3, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives Grip strength is a reliable marker of biological vitality and it typically demonstrates an expected decline in older adults. According to the common-cause hypothesis, there is also a significant association between cognitive and physical function in older adults. Some specific cognitive functions have been shown to be associated with grip strength trajectories with most research solely focused on cutoff points or mean cognitive performance. In the present study, we examine whether a measure of cognitive dispersion might be more informative. We therefore used an index that quantifies dispersion in cognitive scores across multiple cognitive tests, shown to be associated with detrimental outcomes in older adults. Research Design and Methods Using repeated grip strength measures from men and women aged 80 and older, free of dementia in the OCTO-Twin study, we estimated aging-related grip strength trajectories. We examined the association of cognitive dispersion and mean cognitive function with grip strength level and aging-related rate of change, accounting for known risk factors. Results Cognitive dispersion was associated with grip strength trajectories in men and the association varied by mean cognitive performance, whereas we found no association in women. Discussion and Implications Our results provide evidence of a sex-specific vitality association between cognitive dispersion and aging-related trajectories of grip strength. Our results support the call for integration of sex and gender in health promotion and intervention research.
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| 227. |
- Weman-Josefsson, Karin Anna, 1975-
(författare)
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EXPLORING MOTIVATIONAL MECHANISMS IN EXERCISE BEHAVIOUR : Applying Self-determination theory in a person-centred approach
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Involvement in physical activity (PA) and exercise behaviour is multifaceted and depends on bidirectional correlations between multiple factors; one avenue to increase the understanding of sustainable exercise behaviours would be to employ a motivational perspective. In this thesis, this was done by placing the primary focus on Self-determination theory (SDT) as a person-centred approach to study the motivational mechanisms believed to impact exercise behaviour based on the SDT process model. Study 1, conducted in a cross-sectional design, included 1,091 members of a web-based exercise service. Based on sophisticated mediation analysis, the results support the hypothesized associations between latent constructs and exercise behaviour in the related steps of the SDT process model. Moreover, moderating effects were discovered, demonstrating that these associations could differ in different subgroups based on gender and age. The results of Study 1 thereby represent a first indication that exercise intervention design might benefit from slightly different approaches when addressing different demographical groups like gender and age. Study 2 was conducted in a two-wave RCT design to test an SDT-informed intervention on 64 voluntary participants. Components of Motivational interviewing (MI), the Relapse prevention model (RPM) and Cognitive behavioural therapy (CBT) were used as practical application guidelines to deliver the intervention content. Results showed intervention effects on exercise level, exercise intensity and motivation quality as well as mediating effects of the RAI (Relative Autonomy Index; an index of the degree of self-determination), and identified regulation in relation to exercise behaviour. The experimental group also demonstrated significantly lower levels of extrinsic motivation than the control group post-intervention. Besides strong support for applying the basic tenets of SDT in the exercise domain, there are some main findings in this thesis. First of all, self-determined motivation was found to act as a mediating variable in the relationship between psychological need satisfaction and exercise, and these patterns of indirect effects differed across age and gender. This indicates that mechanisms in the SDT process model could vary (qualitatively) depending on subgroup, which carries potential implications for practice. Second, the results of Study 2 also provide evidence that the mediating mechanisms of the process model could be manipulated in an intervention, e.g. by creating need-supportive environments facilitating internalization and subsequent exercise behaviour. Furthermore, both studies demonstrated that identified regulation plays a prominent role in the motivational processes, supporting the significance of promoting internalization in activities like exercise. Finally, this thesis represents prospective value for the utility of employing a polytheoretical approach in exercise intervention design, more specifically regarding the prosperous outlooks in combining SDT with other theories and methods.
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| 228. |
- Wikby, A, et al.
(författare)
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An immune risk phenotype, cognitive impairment and survival in very late life: The impact of alosta-tic load in Swedish Octo- and Nongenarian humans
- 2005
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Ingår i: Journal Gerontology: Biological Science. ; , s. 556-565
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Tidskriftsartikel (refereegranskat)abstract
- In the previous OCTO longitudinal study, we identified an immune risk pheno-type (IRP) of high CD8 and low CD4 numbers and poor proliferative response. We also demonstrated that cognitive impairment constitutes a major predictor of nonsurvival. In the present NONA longitudinal study, we simultaneously exam-ine in a model of allostatic load IRP and compromised cognition in 4-year survival in a population-based sample (n = 138, 86-94 years). Immune system measure-ments consisted of determinations of T-cell subsets, plasma interleukin 6 and cy-tomegalovirus and Epstein-Barr virus serology. Interleukin 2 responsiveness to concanavalin A, using data from the previous OCTO (octogenarians) immune study, hereafter OCTO immune, was also examined. Cognitive status was rated using a battery of neuropsychological tests. Logistic regression indicated that the IRP and cognitive impairment together predicted 58% of observed deaths. IRP was associated with late differentiated CD8+CD28-CD27- cells (p < .001), de-creased interleukin 2 responsiveness (p < .05) and persistent viral infection (p < .01). Cognitive impairment was associated with increased plasma interleukin 6 (p < .001). IRP individuals with cognitive impairment were all deceased at the fol-low-up, indicating an allostatic overload.
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| 229. |
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| 230. |
- Wikby, A, et al.
(författare)
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The immune risk phenotype is associated with Il-6 in the terminal decline stage: Findings from the Swedish NONA immune longitudinal study of very late life functioning
- 2006
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Ingår i: Mechanisms Ageing and Development. - : Elsevier. ; 127:8, s. 695-704
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Tidskriftsartikel (refereegranskat)abstract
- In the present NONA immune longitudinal study, we further examine the previously identi-fied T cell immune risk phenotype (IRP), relative inflammatory activity, morbidity and 2-year mortality in very old individuals >90 years. T-cell subsets as well as the inflammatory mark-ers IL-6, IL-10, C-reactive protein, transthyretin and albumin were evaluated. IRP and low-grade inflammation predicted 57% of observed deaths and 97% of survival over 2 years, and was not significantly affected by individuals' health status, suggesting that the physiological ageing processes of T-cell immunosenescence and low-grade inflammation are of primary importance in late life survival. IRP non-survivors showed only a minor inflammatory activity at baseline, but had in contrast to survivors developed increased activity at follow-up. The re-sults suggest a sequence of stages for IRP individuals that begin with acquisition of CMV in-fection in earlier life, followed by generation of CD8+CD28- cells to control persistent CMV infection and eventually the development of an IRP. Intriguingly, we also found that rare in-dividuals moved out of the IRP category by a process of immune suppression, including in-creases in IL-6 and IL-10 and decreases in the number of CD3+CD8+CD28- cells. The fur-ther characterisation of these exceptional individuals may allow insight into remedial ap-proaches for those who remain in the IRP category until death
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