| 1. |
- Bai, Ge, et al.
(författare)
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Frailty and the risk of dementia : is the association explained by shared environmental and genetic factors?
- 2021
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Ingår i: BMC Medicine. - : BioMed Central. - 1741-7015. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Frailty has been identified as a risk factor for cognitive impairment and dementia. However, it is not known whether familial factors, such as genetics and shared environmental factors, underlie this association. We analyzed the association between frailty and the risk of dementia in a large twin cohort and examined the role of familial factors in the association. Methods The Rockwood frailty index (FI) based on 44 health deficits was used to assess frailty. The population-level association between FI and the risk of all-cause dementia was analyzed in 41,550 participants of the Screening Across the Lifespan Twin (SALT) study (full sample, aged 41-97 years at baseline), using Cox and competing risk models. A subsample of 10,487 SALT participants aged 65 and older who received a cognitive assessment (cognitive sample) was used in a sensitivity analysis to assess the effect of baseline cognitive level on the FI-dementia association. To analyze the influence of familial effects on the FI-dementia association, a within-pair analysis was performed. The within-pair model was also used to assess whether the risk conferred by frailty varies by age at FI assessment. Results A total of 3183 individuals were diagnosed with dementia during the 19-year follow-up. A 10% increase in FI was associated with an increased risk of dementia (hazard ratio [HR] 1.17 (95% confidence interval [CI] 1.07, 1.18)) in the full sample adjusted for age, sex, education, and tobacco use. A significant association was likewise found in the cognitive sample, with an HR of 1.13 (95% CI 1.09, 1.20), adjusted for age, sex, and cognitive level at baseline. The associations were not attenuated when adjusted for APOE e4 carrier status or considering the competing risk of death. After adjusting for familial effects, we found no evidence for statistically significant attenuation of the effect. The risk conferred by higher FI on dementia was constant after age 50 until very old age. Conclusions A higher level of frailty predicts the risk of dementia and the association appears independent of familial factors. Targeting frailty might thus contribute to preventing or delaying dementia.
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| 2. |
- Bai, Ge, et al.
(författare)
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Frailty trajectories in three longitudinal studies of aging : Is the level or the rate of change more predictive of mortality?
- 2021
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Ingår i: Age and Ageing. - : Oxford University Press. - 0002-0729 .- 1468-2834. ; 50:6, s. 2174-2182
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: frailty shows an upward trajectory with age, and higher levels increase the risk of mortality. However, it is less known whether the shape of frailty trajectories differs by age at death or whether the rate of change in frailty is associated with mortality.OBJECTIVES: to assess population frailty trajectories by age at death and to analyse whether the current level of the frailty index (FI) i.e. the most recent measurement or the person-specific rate of change is more predictive of mortality.METHODS: 3,689 individuals from three population-based cohorts with up to 15 repeated measurements of the Rockwood frailty index were analysed. The FI trajectories were assessed by stratifying the sample into four age-at-death groups: <70, 70-80, 80-90 and >90 years. Generalised survival models were used in the survival analysis.RESULTS: the FI trajectories by age at death showed that those who died at <70 years had a steadily increasing trajectory throughout the 40 years before death, whereas those who died at the oldest ages only accrued deficits from age ~75 onwards. Higher level of FI was independently associated with increased risk of mortality (hazard ratio 1.68, 95% confidence interval 1.47-1.91), whereas the rate of change was no longer significant after accounting for the current FI level. The effect of the FI level did not weaken with time elapsed since the last measurement.CONCLUSIONS: Frailty trajectories differ as a function of age-at-death category. The current level of FI is a stronger marker for risk stratification than the rate of change.
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| 3. |
- Bannon, Brittany L., et al.
(författare)
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Confirmatory factor analysis of illness behavior in the Swedish Adoption/Twin Study of Aging (SATSA)
- 2017
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Ingår i: Annals of Behavioral Medicine. - : Springer. - 0883-6612 .- 1532-4796. ; 51:Suppl. 1, s. S2654-S2655
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Tidskriftsartikel (refereegranskat)abstract
- Background: Illness behaviors—or affective, cognitive, and behavioral responses to symptoms of illness—predict patient outcomes, including symptom exacerbation and functional recovery, and they account for a large proportion of U.S. healthcare costs. Although priorcross-sectional work has examined illness behaviors like symptom reporting in isolation, the measurement of illness behavior using a longitudinal, multi-indicator approach has yet to be explored.Aim: We evaluated illness behavior as a latent, developmental construct in the Swedish Adoption/Twin Study of Aging (SATSA).Method: Participants were up to 1,886 individuals (from 1,223 twin pairs) ages 29 to 102 years (Mage baseline = 62.32 years; SD =13.69; 59% Female). Illness behavior indicators included somatic complaints, non-prescription medication use, pain-related disability and perceived illness complications. The psychomotor retardation subscale of the CES-D was used to index somatic complaints, and medication use was a simple composite of 9 dichotomous items on participants’ use of non-prescription medications, such as over-the-counter analgesics, in the previous month. Pain-related disability included a simple composite of three dichotomous items on the presence of neck,back, or shoulder pain that prevented participants from performing daily tasks or activities. Perceived illness disability was a composite of difference scores, calculated from subtracting a physician panel’s objective ratings of disability for each of 35 medical conditions (on a 3-pointscale; 1= Little or no disability; 3= Severe disability) from participants’ self-ratings of how much each of the same endorsed medical conditions interfered with their daily lives (on the same 3-point scale; 1= Not at all; 3= A lot). Positive composite scores reflected higher perceived disability relative to what was expected from the objective ratings, whereas a composite score of zero reflected “accuracy” or agreement in perceived illness complications. Confirmatory Factor Analysis (CFA) was used to evaluate invariance in the loadings of these four indicatorson a latent illness behavior factor across four questionnaire waves (1987-2004).Findings: Confirmatory factor analyses revealed moderate factor loadings of the four indicators (standardized loadings ranged from .49 to .52, all ps < .0001). Also, practical fit indices from the nested model comparisons suggested strong factorial invariance in the loadings across time (CFI = .96; TLI = .95, RMSEA= .03, 90% CI: [.026, .035]).Conclusion: Illness behavior as a latent, multi-indicator construct represents a promising focus for longitudinal work on behavior change and maintenance.
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| 4. |
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| 5. |
- Bokenberger, Kathleen, et al.
(författare)
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Association between sleep characteristics and incident dementia accounting for baseline cognitive status : A prospective population-based study
- 2017
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Ingår i: The journals of gerontology. Series A, Biological sciences and medical sciences. - : Oxford University Press. - 1079-5006 .- 1758-535X. ; 72:1, s. 134-139
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Tidskriftsartikel (refereegranskat)abstract
- Background: While research has shown that sleep disorders are prevalent among people with dementia, the temporal relationship is unclear. We investigated whether atypical sleep characteristics were associated with incident dementia while accounting for baseline cognitive functioning.Methods: Screening Across the Lifespan Twin Study (SALT) participants were 11,247 individuals from the Swedish Twin Registry who were at least 65 years at baseline (1998-2002). Sleep and baseline cognitive functioning were assessed via the SALT telephone screening interview. Data on dementia diagnoses came from national health registers. Cox regression was performed to estimate hazard ratios (HR) for dementia.Results: After 17 years of follow-up, 1,850 dementia cases were identified. Short (≤ 6 hours) and extended (> 9 hours) time-in-bed (TIB) compared to the middle reference group (HR=1.40, 95% CI=1.06-1.85, HR=1.11, 95% CI=1.00-1.24, respectively) and rising at 8:00AM or later compared to earlier rising (HR=1.12, 95% CI=1.01-1.24) were associated with higher dementia incidence. Bedtime, sleep quality, restorative sleep, and heavy snoring were not significant predictors. Findings stratified by baseline cognitive status indicated that the association between short TIB and dementia remained in those cognitively intact at the start.Conclusions: Short and extended TIB as well as delayed rising among older adults predicted increased dementia incidence in the following 17 years. The pattern of findings suggests that extended TIB and late rising represent prodromal features whereas short TIB appeared to be a risk factor for dementia.
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| 6. |
- Bokenberger, Kathleen, et al.
(författare)
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Shift work and cognitive aging : A longitudinal study
- 2017
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Nordic Association of Occupational Safety and Health (NOROSH). - 0355-3140 .- 1795-990X. ; 43:5, s. 485-493
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The few studies of shift work and late life cognitive functioning have yielded mixed findings. The aim of the present study is to estimate the association between shift-work experience and change in cognitive performance before and after retirement age among older adults who were gainfully employed.Methods Five hundred and ninety five participants with no dementia were followed up for a mean of 17.6 standard deviation (SD) 8.8 years from a Swedish population-based sample. Participants had self-reported information on any type of shift-work experience (ever/never) in 1984 and measures of cognitive performance (verbal, spatial, memory, processing speed, and general cognitive ability) from up to 9 waves of cognitive assessments during 1986–2012. Night work history (ever/never) from 1998–2002 was available from a subsample (N=320). Early adult cognitive test scores were available for 77 men.Results In latent growth curve modeling, there were no main effects of "any-type" or night shift work on the mean scores or rate of change in any of the cognitive domains. An interaction effect between any-type shift work and education on cognitive performance at retirement was noted. Lower-educated shift workers performed better on cognitive tests than lower-educated day workers at retirement. Sensitivity analyses, however, indicated that the interactions appeared to be driven by selection effects. Lower-educated day workers demonstrated poorer cognitive ability in early adulthood than lower-educated shift workers, who may have selected jobs entailing higher cognitive demand.Conclusion There was no difference in late-life cognitive aging between individuals with a history of working shifts compared to those who had typical day work schedules during midlife.
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| 7. |
- Dahl, Anna, 1975-, et al.
(författare)
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Being overweight in midlife is associated with lower cognitive ability and steeper cognitive decline in late life
- 2010
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Ingår i: The journals of gerontology. Series A, Biological sciences and medical sciences. - : Oxford University Press. - 1079-5006 .- 1758-535X. ; 65A:1, s. 57-62
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Although an increasing body of evidence links being overweight in midlife with an increased risk for dementia in late life, no studies have examined the association between being overweight in midlife and cognitive ability in late life. Our aim was to examine the association between being overweight in midlife as measured by body mass index (BMI) and cognitive ability assessed over time. METHODS: Participants in the Swedish Adoption/Twin Study Aging were derived from a population-based sample. The participants completed baseline surveys in 1963 or 1973 (mean age 41.6 years, range 25-63 years). The surveys included questions about height, weight, diseases, and lifestyle factors. Beginning in 1986, the same individuals were assessed on neuropsychological tests every 3 years (except in 1995) until 2002. During the study period, 781 individuals who were 50 years and older (60% women) had at least one complete neuropsychological assessment. A composite score of general cognitive ability was derived from the cognitive test battery for each measurement occasion. RESULTS: Latent growth curve models adjusted for twinness showed that persons with higher midlife BMI scores had significantly lower general cognitive ability and significantly steeper longitudinal decline than their thinner counterparts. The association did not change substantially when persons who developed dementia during the study period were excluded from the analysis. CONCLUSIONS: Higher midlife BMI scores precede lower general cognitive ability and steeper cognitive decline in both men and women. The association does not seem to be mediated by an increased risk for dementia
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| 8. |
- Dahl, Anna, et al.
(författare)
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Body mass index across midlife and cognitive change in late life
- 2013
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 37, s. 296-302
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: High midlife body mass index (BMI) has been linked to a greater risk of dementia in late life, but few have studied the effect of BMI across midlife on cognitive abilities and cognitive change in a dementia-free sample. METHODS: We investigated the association between BMI, measured twice across midlife (mean age 40 and 61 years, respectively), and cognitive change in four domains across two decades in the Swedish Adoption/Twin Study of Aging. RESULTS: Latent growth curve models fitted to data from 657 non-demented participants showed that persons who were overweight/obese in early midlife had significantly lower cognitive performance across domains in late life and significantly steeper decline in perceptual speed, adjusting for cardio-metabolic factors. Both underweight and overweight/obesity in late midlife were associated with lower cognitive abilities in late life. However, the association between underweight and low cognitive abilities did not remain significant when weight decline between early and late midlife was controlled for. CONCLUSION: There is a negative effect on cognitive abilities later in life related to being overweight/obese across midlife. Moreover, weight decline across midlife rather than low weight in late midlife per se was associated with low cognitive abilities. Weight patterns across midlife may be prodromal markers of late life cognitive health.
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| 9. |
- Dahl, Anna K., et al.
(författare)
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Agreement between self-reported and measured height, weight and body mass index in old age : a longitudinal study with 20 years of follow-up
- 2010
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Ingår i: Age and Ageing. - : Oxford University Press. - 0002-0729 .- 1468-2834. ; 39:4, s. 445-451
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Tidskriftsartikel (refereegranskat)abstract
- Background: self-reported body mass index (BMI) based on self-reported height and weight is a widely used measure of adiposity in epidemiological research. Knowledge about the accuracy of these measures in late life is scarce.Objective: the study aimed to evaluate the accuracy and changes in accuracy of self-reported height, weight and BMI calculated from self-reported height and weight in late life.Design: a longitudinal population-based study with five times of follow-up was conducted.Participants: seven hundred seventy-four community-living men and women, aged 40–88 at baseline (mean age 63.9), included in The Swedish Adoption/Twin Study of Aging.Methods: participants self-reported their height and weight in a questionnaire, and height and weight were measured by experienced research nurses at an in-person testing five times during a 20-year period. BMI was calculated as weight (kilogramme)/height (metre)2.Results: latent growth curve modelling showed an increase in the mean difference between self-reported and measured values over time for height (0.038 cm/year) and BMI (0.016 kg/m2/year), but not for weight.Conclusions: there is a very small increase in the mean difference between self-reported and measured BMI with ageing, which probably would not affect the results when self-reported BMI is used as a continuous variable in longitudinal studies.
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| 10. |
- Dahl, Anna K, et al.
(författare)
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Is Self-reported Body Mass Index Less Reliable in Late Life?
- 2010
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Konferensbidrag (refereegranskat)abstract
- Objectives: Self-reported Body Mass Index (BMI) based on self-reported height and weight is a widely used measure of adiposity in epidemiological research. Knowledge about the accuracy of these measures in late life is scarce, and especially if there is intra-individual changes over time. Methods: Seven hundred seventy-four men and women, aged 40 to 88 at baseline (mean age 63.9), in The Swedish Adoption/Twin Study of Aging self-reported and had their height and weight measured by experienced research nurses five times during a twenty year period. BMI was calculated as weight (kilos)/height (meter)2. Results: There was significant correlation between self-reported and measured height (0.97-0.98), weight (0.97-0.98), and BMI (0.93-0.95) at each measurement occasion, and substantial agreement for BMI as a categorical variable (Kappa coefficient 0.72-0.81). Latent growth curve modeling showed an increase in the mean difference between self-reported and measured values over time for height (0.04 cm/year) and BMI (0.02 kg/m2/year), but not for weight. Conclusions: There is a very small significant increase in the mean difference between self-reported and measured BMI with aging, mainly due to unawareness of changes in height, which probably would not affect the results when self-reported BMI is used as a continuous variable in longitudinal studies.
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