| 1. |
- Laukka, Erika J., et al.
(author)
-
Genetic Effects on Old-Age Cognitive Functioning : A Population-Based Study
- 2013
-
In: Psychology and Aging. - : American Psychological Association (APA). - 0882-7974 .- 1939-1498. ; 28:1, s. 262-274
-
Journal article (peer-reviewed)abstract
- Associations between genotypes and cognitive outcomes may provide clues as to which mechanisms cause individual differences in old-age cognitive performance. We investigated the effects of five polymorphisms on cognitive functioning in a population-based sample of 2,694 persons without dementia (60-102 years). A structural equation model (SEM) was fit to the cognitive data, yielding five specific latent factors (perceptual speed, episodic memory, semantic memory, category fluency, and letter fluency), as well as a global cognitive factor. These factors showed the expected associations with chronological age. Genotyping was performed for five single-nucleotide polymorphisms that have been associated with cognitive performance: APOE (rs429358), COMT (rs4680), BDNF (rs6265), KIBRA (rs17070145), and CLSTN2 (rs6439886). After controlling for age, gender, and education, as well as correcting for multiple comparisons, we observed negative effects of being an APOE ε4 carrier on episodic memory and perceptual speed. Furthermore, being a CLSTN2 TT carrier was associated with poorer semantic memory. For the global factor, the same pattern of results was observed. In addition, being a BDNF any A carrier was associated with better cognitive performance. Also, older age was associated with stronger genetic effects of APOE on global cognition. However, this interaction effect was partly driven by the presence of preclinical dementia cases in our sample. Similarly, excluding future dementia cases attenuated the effects of APOE on episodic memory and global cognition, suggesting that part of the effects of APOE on old-age cognitive performance may be driven by dementia-related processes.
|
|
| 2. |
- Marseglia, Anna, et al.
(author)
-
Cognitive Trajectories of Older Adults With Prediabetes and Diabetes : A Population-Based Cohort Study
- 2018
-
In: The journals of gerontology. Series A, Biological sciences and medical sciences. - : Oxford University Press. - 1079-5006 .- 1758-535X. ; 73:3, s. 400-406
-
Journal article (peer-reviewed)abstract
- Background Diabetes has been linked to dementia risk; however, the cognitive trajectories in older adults with diabetes remain unclear. We aimed to investigate the effect of prediabetes and diabetes on cognitive trajectories among cognitively intact older adults in a long-term follow-up study.Methods Within the Swedish Adoption/Twin Study of Aging, 793 cognitively intact older adults aged ≥50 were identified at baseline and followed for up to 23 years. Based on standardized scores from 11 cognitive tests, administered at baseline and up to seven follow-ups, four cognitive domains (verbal abilities, spatial/fluid, memory, perceptual speed) were identified by principal-component analysis. Prediabetes was defined according to blood glucose levels in diabetes-free participants. Diabetes was ascertained based on self-report, hypoglycemic medication use and blood glucose levels. Data were analyzed with linear mixed-effect models adjusting for potential confounders.Results At baseline, 68 participants (8.6%) had prediabetes and 45 (5.7%) had diabetes. Compared to diabetes-free individuals, people with diabetes had a steeper decline over time in perceptual speed and verbal abilities. The annual declines in these domains were greater than the annual decline in memory. Prediabetes was associated with lower performance in memory in middle-age, but also associated with a less steep memory decline over the follow-up.Conclusions Diabetes is associated with a faster decline in perceptual speed and verbal abilities, while prediabetes is associated with lower memory performance in middle-age. However, the detrimental effects of hyperglycemia seem to not affect memory over time.
|
|
| 3. |
- Andel, Ross, et al.
(author)
-
Work-related exposure to extremely low-frequency magnetic fields and dementia: results from the population-based study of dementia in Swedish twins.
- 2010
-
In: The journals of gerontology. Series A, Biological sciences and medical sciences. - : Oxford University Press (OUP). - 1758-535X .- 1079-5006. ; 65:11, s. 1220-7
-
Journal article (peer-reviewed)abstract
- BACKGROUND: We examined the association between extremely low-frequency magnetic fields (EMF) and the risk of dementia and Alzheimer's disease using all 9,508 individuals from the Study of Dementia in Swedish Twins (HARMONY) with valid occupational and diagnostic data. METHODS: Dementia diagnoses were based on telephone screening followed by in-person clinical workup. Main lifetime occupation was coded according to an established EMF exposure matrix. Covariates were age, gender, education, vascular risk factors, and complexity of work. Based on previous research, data were also analyzed separately for cases with disease onset by age 75 years versus later, men versus women, and those with manual versus nonmanual main occupation. We used generalized estimating equations with the entire sample (to adjust for the inclusion of complete twin pairs) and conditional logistic regression with complete twin pairs only. RESULTS: Level of EMF exposure was not significantly associated with dementia or Alzheimer's disease. However, in stratified analyses, medium and high levels of EMF exposure were associated with increased dementia risk compared with low level in cases with onset by age 75 years (odds ratio: 1.94, 95% confidence interval: 1.07-3.65 for medium, odds ratio: 2.01, 95% confidence interval: 1.10-3.65 for high) and in participants with manual occupations (odds ratio: 1.81, 95% confidence interval: 1.06-3.09 for medium, odds ratio: 1.75, 95% confidence interval: 1.00-3.05 for high). Results with 42 twin pairs discordant for dementia did not reach statistical significance. CONCLUSIONS: Occupational EMF exposure appears relevant primarily to dementia with an earlier onset and among former manual workers.
|
|
| 4. |
- Andel, Ross, et al.
(author)
-
Work-Related Stress May Increase the Risk of Vascular Dementia
- 2012
-
In: Journal of The American Geriatrics Society. - : Wiley. - 0002-8614 .- 1532-5415. ; 60:1, s. 60-67
-
Journal article (peer-reviewed)abstract
- OBJECTIVES: To examine job control, job demands, social support at work, and job strain (ratio of demands to control) in relation to risk of any dementia, Alzheimer's disease (AD), and vascular dementia (VaD). DESIGN: Cohort study. SETTING: The population-based Study of Dementia in Swedish Twins. PARTICIPANTS: Two hundred fifty-seven people with dementia (167 AD, 46 VaD) and 9,849 without. MEASUREMENTS: Dementia diagnoses were based on telephone screening for cognitive impairment followed by in-person clinical examination. An established job exposure matrix was matched to main occupation categories to measure work characteristics. RESULTS: In generalized estimating equations (adjusted for the inclusion of complete twin pairs), lower job control was associated with greater risk of any dementia (odds ratio (OR) = 1.17, 95% confidence interval (CI) = 1.04-1.31) and VaD specifically (OR = 1.39, 95% CI = 1.07-1.81). Lower social support at work was associated with greater risk of dementia (OR = 1.15, 95% CI = 1.03-1.28), AD (OR = 1.14, 95% CI = 1.00-1.31), and VaD (OR = 1.28, 95% CI = 1.02-1.60). Greater job strain was associated with greater risk of VaD only (OR = 1.28, 95% CI = 1.02-1.60), especially in combination with low social support (OR = 1.35, 95% CI = 1.11-1.64). Age, sex, and education were controlled for. Work complexity, manual work, and vascular disease did not explain the results. No differences in work-related stress scores were observed in the 54 twin pairs discordant for dementia, although only two pairs included a twin with VaD. CONCLUSION: Work-related stress, including low job control and low social support at work, may increase the risk of dementia, particularly VaD. Modification to work environment, including attention to social context and provision of meaningful roles for employees, may contribute to efforts to promote cognitive health.
|
|
| 5. |
- Brommelhoff, Jessica A, et al.
(author)
-
Depression as a risk factor or prodromal feature for dementia? Findings in a population-based sample of Swedish twins.
- 2009
-
In: Psychology and aging. - : American Psychological Association (APA). - 0882-7974 .- 1939-1498. ; 24:2, s. 373-84
-
Journal article (peer-reviewed)abstract
- This study tested whether history of depression is associated with an increased likelihood of dementia, and whether a first depressive episode earlier in life is associated with increased dementia risk, or whether only depressive episodes close in time to dementia onset are related to dementia. Depression information came from national hospital discharge registries, medical history, and medical records. Dementia was diagnosed clinically. In case-control results, individuals with recent registry-identified depression were 3.9 times more likely than those with no registry-identified depression history to have dementia, whereas registry-identified depression earlier in life was not associated with dementia risk. Each 1-year increase in time between depression onset and dementia onset or equivalent age decreased the likelihood of dementia by 8.4%. In co-twin control analyses, twins with prior depression were 3.0 times more likely to have dementia than their nondepressed twin partners, with a similar age of depression gradient. These findings suggest that after partially controlling for genetic influences, late-life depression for many individuals may be a prodrome rather than a risk factor for dementia.
|
|
| 6. |
- Ferencz, Beata, et al.
(author)
-
The influence of APOE and TOMM40 polymorphisms on hippocampal volume and episodic memory in old age
- 2013
-
In: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 7
-
Journal article (peer-reviewed)abstract
- Mitochondrial dysfunction is implicated in neurodegenerative disorders, such as Alzheimer's disease (AD). Translocase of outer mitochondrial membrane 40 (TOMM40) may be influential in this regard by influencing mitochondrial neurotoxicity. Little is known about the influence of the TOMM40 gene on hippocampal (HC) volume and episodic memory (EM), particularly in healthy older adults. Thus, we sought to discern the influence of TOMM40 single nucleotide polymorphisms (SNPs), which have previously been associated with medial temporal lobe integrity (rs11556505 and rs2075650), on HC volume and EM. The study sample consisted of individuals from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K) who were free of dementia and known neurological disorders, and 6087 years of age (n = 424). EM was measured by using a 16-item word list with a 2-min free recall period and delineation of the HC was performed manually. The influence of Apolipoprotein E (APOE) and TOMM40 was assessed by 2 x 2 ANOVAs and partial correlations. There was no effect of APOE and TOMM40 on EM performance and HC volume. However, partial correlations revealed that HC volume was positively associated with free recall performance (r = 0.21, p < 0.01, r(2) = 0.04). When further stratified for TOMM40, the observed association between HC volume and free recall in APOE epsilon 4 carriers was present in combination with TOMM40 rs11556505 any T (r = 0.28, p < 0.01, R-2 = 0.08) and rs2075650 any G (r = 0.28, p < 0.01, R-2 = 0.08) risk alleles. This pattern might reflect higher reliance on HC volume for adequate EM performance among APOE epsilon 4 carriers with additional TOMM40 risk alleles suggesting that the TOMM40 gene cannot merely be considered a marker of APOE genotype. Nevertheless, neither APOE nor TOMM40 influenced HC volume or EM in this population-based sample of cognitively intact individuals over the age of 60.
|
|
| 7. |
- Gerritsen, L., et al.
(author)
-
The influence of negative life events on hippocampal and amygdala volumes in old age : a life-course perspective
- 2014
-
In: Psychological Medicine. - 0033-2917 .- 1469-8978. ; 45:6, s. 1219-1228
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Psychosocial stress has been related to changes in the nervous system, with both adaptive and maladaptive consequences. The aim of this study was to examine the relationship of negative events experienced throughout the entire lifespan and hippocampal and amygdala volumes in older adults.METHOD: In 466 non-demented old adults (age range 60-96 years, 58% female), hippocampal and amygdala volumes were segmented using Freesurfer. Negative life events and the age at which these events occurred were assessed by means of a structured questionnaire. Using generalized linear models, hippocampal and amygdala volumes were estimated with life events as independent variables. The statistical analyses were adjusted for age, gender, intracranial volume, lifestyle factors, cardiovascular risk factors, depressive symptoms, and cognitive functioning.RESULTS: Total number of negative life events and of late-life events, but not of early-life, early-adulthood, or middle-adulthood events, was related to larger amygdala volume. There were interactions of early-life events with age and gender. Participants who reported two or more early-life events had significantly smaller amygdala and hippocampal volumes with increasing age. Furthermore, smaller hippocampal volume was found in men who reported two or more early-life events, but not in women.CONCLUSIONS: These results suggest that the effect of negative life events on the brain depends on the time when the events occurred, with the strongest effects observed during the critical time periods of early and late life.
|
|
| 8. |
- Hughes, Tiffany F, et al.
(author)
-
Midlife fruit and vegetable consumption and risk of dementia in later life in Swedish twins.
- 2010
-
In: The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry. - 1545-7214 .- 1064-7481. ; 18:5, s. 413-20
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Diet may be associated with risk of dementia and Alzheimer disease (AD). The authors examined the association between fruit and vegetable consumption in midlife and risk for all types of dementia and AD. METHODS: Participants were 3,779 members of the Swedish Twin Registry who completed a diet questionnaire approximately 30 years before cognitive screening and full clinical evaluation for dementia as part of the study of dementia in Swedish Twins (HARMONY) study. Among the participants, 355 twins were diagnosed with dementia. Among these, 81 twin pairs were discordant for dementia (50 discordant for AD). Data were analyzed with logistic regression for the entire sample using generalized estimating equations to adjust for relatedness of twins and with conditional logistic regression for the co-twin control design. RESULTS: In fully adjusted models, a medium or great proportion of fruits and vegetables in the diet, compared with no or small, was associated with a decreased risk of dementia and AD. This effect was observed among women and those with angina. Similar, but nonsignificant, odds ratios were found in the co-twin control analyses. CONCLUSION: The findings suggest that higher fruit and vegetable consumption may reduce the risk of dementia, especially among women and those with angina pectoris in midlife.
|
|
| 9. |
|
|
| 10. |
- Laukka, Erika J., et al.
(author)
-
Markers of olfactory dysfunction and progression to dementia : A 12-year population-based study
- 2023
-
In: Alzheimer's & Dementia. - : John Wiley & Sons. - 1552-5260 .- 1552-5279. ; 19:7, s. 3019-3027
-
Journal article (peer-reviewed)abstract
- Introduction: We evaluated markers of olfactory dysfunction (OD) for estimating hazard of dementia in older adults.Methods: Mild (hyposmia) and severe (anosmia) OD was classified in a population-based study of dementia-free persons (SNAC-K; n = 2473; mean age = 70 years) using the Sniffin sticks odor identification task. Combined variables were created for objective and subjective OD and for OD and APOE status. Hazard of dementia across 12 years was estimated with Cox regression.Results: OD was associated with increased hazard of dementia (2.01; 95% confidence interval [CI] 1.60-2.52), with the strongest association for anosmia (2.92; 95% CI 2.14-3.98). Results remained consistent after adjusting for potential confounders and across age and sex subgroups. APOE ε4 carriers with anosmia had the highest hazard of dementia (ε4: 6.95; 95% CI 4.16-11.62; ε4/ε4: 19.84; 95% CI 6.17-63.78).Discussion: OD is associated with increased risk of dementia, especially severe impairment in combination with genetic risk of Alzheimer's disease.
|
|
