| 1. |
- Dahl, Anna, et al.
(författare)
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Identification of dementia in epidemiological research : A study on the usefulness of various data sources
- 2007
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Ingår i: Aging Clinical and Experimental Research. - : Springer Nature Switzerland AG. - 1594-0667 .- 1720-8319. ; 19:5, s. 381-389
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Prevalence and incidence ratios of dementia in epidemiological studies vary according to the data source used. Medical records, cognitive tests, and registry information are sources frequently used to differentiate dementia from normal aging. The aim of the present study was to compare the identification of dementia from these different sources with that from consensus diagnosis. Methods: 498 elderly people (age range 70–81 at baseline) enrolled in a Swedish population-based longitudinal twin study (Gender) were evaluated on physical and mental health and interviewed for their socio-demographic background three times during an eight-year period. Reviews of medical records and the Swedish Discharge Registry (DR) were conducted. The 10th percentile was used to differentiate between dementia and non-dementia in all cognitive tests. Scores of 24 or below on the Mini-Mental State Examination (MMSE) (range 1–30) indicated dementia. A consensus conference diagnosed dementia on the basis of total information. The consensus diagnosis was used as the gold standard. Results: MMSE scores (sensitivity 64%, specificity 96%, kappa 0.65) and the review of medical records (sensitivity 57%, specificity 99%, kappa 0.65) were good sources for dementia identification. The precision of medical records increased when recordings of cognitive impairment were included (sensitivity 83%, specificity 98%, kappa 0.84). The discharge registry had low sensitivity (26%) and kappa coefficient (0.31). Conclusions: The present study shows that both review of medical records and MMSE scores are good although not perfect identifiers of dementia. The discharge registry is an uncertain source of dementia identification.
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| 2. |
- Dahl, Anna, 1975-
(författare)
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Body mass index, cognitive ability, and dementia : prospective associations and methodological issues in late life
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aims of the present study were to investigate the association between overweight and cognitive ability and dementia, and to evaluate the usefulness of self-reported body mass index (BMI) in late life and various data sources commonly used in epidemiological studies to identify persons with dementia. Data were drawn from three population-based studies: the Swedish Adoption/Twin Study of Aging (SATSA), Aging in Women and Men: A Longitudinal Study of Gender Differences in Health Behaviour and Health among Elderly (the Gender Study), and the Finnish Lieto Study. In Study I, the agreement between self-reported and measured BMI over time was evaluated among 774 men and women, ages 40 to 88 years at baseline (mean age 63.9) participating in both the questionnaire phase and in-person testing of SATSA. Latent growth curve (LGC) modeling showed a small but significant increase between self-reported and measured BMI (0.02 kg/m2/y) over time, which would probably not affect the results if self-reported BMI were used as a continuous variable in longitudinal research. In Study II, the agreement between dementia diagnoses from various sources and dementia diagnoses set at a consensus conference was evaluated. Among the 498 elderly people ages 70 to 81 at baseline (mean age 74.5) enrolled in the Gender Study, 87 were diagnosed with dementia during an eight-year period. Review of medical records and nurse evaluations yielded the highest sensitivity (0.83 and 0.80, respectively) and a high specificity (0.98 and 0.96), indicating that these sources might be good proxies of dementia, while data extraction from the Swedish Inpatient Discharge Registry underestimated the prevalence of dementia (sensitivity 0.26). In Study III, the association between being overweight in midlife and cognitive ability in late life was examined in SATSA. The 781 participants ages 25 to 63 at baseline (mean age 41.6) in 1963 or 1973 self-reported their height and weight. From 1986 until 2002, they were assessed five times using a cognitive test battery. LGC models showed that people with higher midlife BMI scores had significantly lower cognitive ability and a significantly steeper decline than their thinner counterparts, an association that persisted when those who developed dementia during the study period were excluded from the analysis. This finding indicates that being overweight might affect cognitive ability independently of dementia. In Study IV, the association between BMI and dementia risk in older persons was described among 605 persons without dementia and ages 65 to 92 at baseline (mean age 70.8) in the Lieto Study. Among these, 86 persons were diagnosed with dementia during eight years of follow-up. Cox regression analyses indicated that for each unit increase in BMI score, the risk of dementia decreased 8% (hazard ratio = 0.92, 95% confidence interval = 0.87–0.97) and the association remained significant when individuals who developed dementia during the first four years of follow-up were excluded from the analyses. This result suggests that low BMI scores are present almost a decade before clinical dementia onset.
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| 3. |
- Hassing, Linda, 1967, et al.
(författare)
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Overweight in midlife and risk of dementia: a 40-year follow-up study
- 2009
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Ingår i: International Journal of Obesity. - : Springer. ; 33:8, s. 893-898
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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
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| 4. |
- Reynolds, Chandra A, et al.
(författare)
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A survey of ABCA1 sequence variation confirms association with dementia.
- 2009
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Ingår i: Human mutation. - : Hindawi Limited. - 1098-1004 .- 1059-7794. ; 30:9, s. 1348-54
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Tidskriftsartikel (refereegranskat)abstract
- We and others have conducted targeted genetic association analyses of ABCA1 in relation to Alzheimer disease risk with a resultant mixture of both support and refutation, but all previous studies have been based upon only a few markers. Here, a detailed survey of genetic variation in the ABCA1 region has been performed in a total of 1,567 Swedish dementia cases (including 1,275 with Alzheimer disease) and 2,203 controls, providing evidence of association with maximum significance at marker rs2230805 (odds ratio [OR]=1.39; 95% confidence interval [CI] 1.23-1.57, p=7.7x10(-8)). Haplotype-based tests confirmed association of this genomic region after excluding rs2230805, and imputation did not reveal additional markers with greater support. Significantly associating markers reside in two distinct linkage disequilibrium blocks with maxima near the promoter and in the terminal exon of a truncated ABCA1 splice form. The putative risk allele of rs2230805 was also found to be associated with reduced cerebrospinal fluid levels of beta-amyloid. The strongest evidence of association was obtained when all forms of dementia were considered together, but effect sizes were similar when only confirmed Alzheimer disease cases were assessed. Results further implicate ABCA1 in dementia, reinforcing the putative involvement of lipid transport in neurodegenerative disease.
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| 5. |
- Dahl, Anna K., 1975-, et al.
(författare)
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Overweight and obesity in old age are not associated with greater dementia risk
- 2008
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Ingår i: Journal of The American Geriatrics Society. - : John Wiley & Sons. - 0002-8614 .- 1532-5415. ; 56:12, s. 2261-2266
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To describe the association between body mass index (BMI) and dementia risk in older persons.DESIGN: Prospective population‐based study, with 8 years of follow‐up.SETTING: The municipality of Lieto, Finland, 1990/91 and 1998/99.PARTICIPANTS: Six hundred five men and women without dementia aged 65 to 92 at baseline (mean age 70.8).MEASUREMENTS: Weight and height were measured at baseline and at the 8‐year follow‐up. Dementia was clinically assessed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria.RESULTS: Eighty‐six persons were diagnosed with dementia. Cox regression analyses, adjusted for age, sex, education, cardiovascular diseases, smoking, and alcohol use, indicated that, for each unit increase in BMI score, the risk of dementia decreased 8% (hazard ratio (HR)=0.92, 95% confidence interval (CI)=0.87–0.97). This association remained significant when individuals who developed dementia early during the first 4 years of follow‐up were excluded from the analyses (HR=0.93, 95% CI=0.86–0.99). Women with high BMI scores had a lower dementia risk (HR=0.90, 95% CI=0.84–0.96). Men with high BMI scores also tended to have a lower dementia risk, although the association did not reach significance (HR=0.95, 95% CI=0.84–1.07).CONCLUSION: Older persons with higher BMI scores have less dementia risk than their counterparts with lower BMI scores. High BMI scores in late life should not necessarily be considered to be a risk factor for dementia.
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