| 1. |
- Beam, Christopher R., et al.
(författare)
-
Estimating Likelihood of Dementia in the Absence of Diagnostic Data : A Latent Dementia Index in 10 Genetically Informed Studies
- 2022
-
Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 90:3, s. 1187-1201
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Epidemiological research on dementia is hampered by differences across studies in how dementia is classified, especially where clinical diagnoses of dementia may not be available. OBJECTIVE: We apply structural equation modeling to estimate dementia likelihood across heterogeneous samples within a multi-study consortium and use the twin design of the sample to validate the results. METHODS: Using 10 twin studies, we implement a latent variable approach that aligns different tests available in each study to assess cognitive, memory, and functional ability. The model separates general cognitive ability from components indicative of dementia. We examine the validity of this continuous latent dementia index (LDI). We then identify cut-off points along the LDI distributions in each study and align them across studies to distinguish individuals with and without probable dementia. Finally, we validate the LDI by determining its heritability and estimating genetic and environmental correlations between the LDI and clinically diagnosed dementia where available. RESULTS: Results indicate that coordinated estimation of LDI across 10 studies has validity against clinically diagnosed dementia. The LDI can be fit to heterogeneous sets of memory, other cognitive, and functional ability variables to extract a score reflective of likelihood of dementia that can be interpreted similarly across studies despite diverse study designs and sampling characteristics. Finally, the same genetic sources of variance strongly contribute to both the LDI and clinical diagnosis. CONCLUSION: This latent dementia indicator approach may serve as a model for other research consortia confronted with similar data integration challenges.
|
|
| 2. |
- Bokenberger, Kathleen, et al.
(författare)
-
Association between sleep characteristics and incident dementia accounting for baseline cognitive status : A prospective population-based study
- 2017
-
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
-
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.
|
|
| 3. |
- Bokenberger, Kathleen, et al.
(författare)
-
The Type A behavior pattern and cardiovascular disease as predictors of dementia
- 2014
-
Ingår i: Health Psychology. - : American Psychological Association (APA). - 0278-6133 .- 1930-7810. ; 33:12, s. 1593-1601
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Research has suggested that greater psychophysiological reactivity to stress increases risk of dementia and that those with the Type A behavior pattern (TABP) are predisposed to elevated stress reactivity and cardiovascular disease (CVD), but no study has evaluated the associations among TABP, CVD, and dementia, prospectively. Hence, the present study aimed to investigate dementia risk in relation to TABP and CVD.Methods: A population-based cohort of 1,069 persons with a baseline mean age of 64.81 years from the Swedish Twin Registry was followed consecutively for up to 23 years. Based on self-reported items, TABP was measured using 6 scales: Ambition, Stress, Hard-driving, Neuroticism, Cynicism, and Paranoia. CVD was self-reported and dementia was diagnosed adhering to Diagnostic and Statistical Manual of Mental Disorders, third edition, revised (DSM-III-R) or Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria.Results: TABP was generally not associated with dementia risk. However, significant interaction effects of stress, paranoia, and cynicism with CVD on dementia risk were observed. That is, for those with CVD, high scores on stress, paranoia, and cynicism were associated with increased risk of dementia (hazard ratio [HR] = 1.43, 95% confidence interval [CI] = 0.95-2.15; HR = 1.39, 95% CI = 0.83-2.33; HR = 1.25, 95% CI = 0.76-2.06, respectively), whereas for those who did not have CVD, high scores on these measures appeared to be protective (HR = 0.76, 95% CI = 0.50-1.14; HR = 0.55, 95% CI = 0.34-0.89; HR = 0.50, 95% CI = 0.29-0.84, respectively).Conclusion: Some features of TABP confer an increased risk for dementia in those with CVD, whereas those without CVD are protected. When evaluating the risk of dementia, CVD and personality traits should be taken into consideration.
|
|
| 4. |
- Dahl, Anna, et al.
(författare)
-
Being overweight in midlife is associated with lower cognitive ability and steeper cognitive decline in late life.
- 2010
-
Ingår i: The journals of gerontology. Series A, Biological sciences and medical sciences. - : Oxford University Press (OUP). - 1758-535X .- 1079-5006. ; 65:1, s. 57-62
-
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.
|
|
| 5. |
|
|
| 6. |
- Dahl, Anna, et al.
(författare)
-
Body mass index across midlife and cognitive change in late life
- 2013
-
Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 37
-
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.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Dahl, Anna, et al.
(författare)
-
Overweight and dementia : a time-varying effect
- 2010
-
Konferensbidrag (refereegranskat)abstract
- Objectives: The negative effects of overweight on cardiometabolic health is well-known. An increasing body of evidence extends the negative effects of midlife overweight to dementia. However, a different picture emerge when overweight is assessed in late life. The time-varying effect of weight status on dementia was evaluated in two prospective Nordic population-based studies. Methods: The participants included in the Swedish Twin Registry self-reported their height and weight in 1963 (mean age 52.5 years). About 25 years later these twins were either included in the SATSA study (50 years and older) or the OCTO-Twin study (80 years and older). Dementia was consequently screened for and diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria presently used at the time of diagnoses. The participants weight and height was assessed at baseline of the Finnish Lieto Study (mean age 70.8) and dementia was screened for and diagnosed according to the DSM-IV criteria eight years later. Results: Logistic regression analyses indicated that midlife overweight was associated with a greater risk of all cause dementia, odds ratio 1.55 (95% confidence interval (CI) = 1.18-2.04), when demographic and cardiometabolic risk factors and diseases were controlled for. However, Cox regression analyses indicated that for each unit increase in BMI score in late life, the risk of dementia decreased 8% (hazard ratio = 0.92, 95% CI = 0.87–0.97), when demographic and cardiometabolic risk factors and diseases were controlled for. The association remained significant when individuals who developed dementia during the first four years of follow-up were excluded from the analyses. Conclusions: Our results indicate there might be a time-varying effect of weight status on dementia. Preclinical dementia might blur the association between weight status and dementia in late life. This needs to be further analysed in studies following the same sample over the life course.
|
|
| 10. |
- Emery, Charles F., et al.
(författare)
-
Evidence of bi-directional associations between depressive symptoms and body mass among older adults
- 2020
-
Ingår i: The journals of gerontology. Series B, Psychological sciences and social sciences. - : Oxford University Press. - 1079-5014 .- 1758-5368. ; 75:8, s. 1689-1698
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Body fat, measured with body mass index (BMI), and obesity are associated with depressive symptoms. Among younger adults there is stronger evidence of obesity leading to depressive symptoms than of depressive symptoms leading to obesity, but the temporal relationship is unknown among older adults. This study utilized dual-change-score models (DCSMs) to determine the directional relationship between body mass and depressive symptoms among older adults.METHOD: Participants (n=1743) from the Swedish Twin Registry (baseline age range 50-96 years) completed at least one assessment of BMI (nurse measurement of height and weight) and the Center for Epidemiologic Studies-Depression scale (CESD). More than half the sample completed three or more assessments, scheduled at intervals of 2-4 years. DCSMs modeled the relationship of BMI and CESD across age, both independently and as part of bivariate relationships.RESULTS: Depressive symptoms contributed to subsequent changes in BMI after age 70, while BMI contributed to subsequent changes in depressive symptoms after age 82. Thus, there is a reciprocal relationship that may change with age. The effect was more pronounced for women.DISCUSSION: The association of BMI and depressive symptoms is bi-directional among older adults, and it appears to be affected by both age and sex.
|
|
