| 11. |
|
|
| 12. |
- Degerman, Sofie, et al.
(författare)
-
Maintained memory in aging is associated with young epigenetic age
- 2017
-
Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 55, s. 167-171
-
Tidskriftsartikel (refereegranskat)abstract
- Epigenetic alterations during aging have been proposed to contribute to decline in physical and cognitive functions, and accelerated epigenetic aging has been associated with disease and all-cause mortality later in life. In this study, we estimated epigenetic age dynamics in groups with different memory trajectories (maintained high performance, average decline, and accelerated decline) over a 15-year period. Epigenetic (DNA-methylation [DNAm]) age was assessed, and delta age (DNAm age - chronological age) was calculated in blood samples at baseline (age: 55-65 years) and 15 years later in 52 age- and gender-matched individuals from the Betula study in Sweden. A lower delta DNAm age was observed for those with maintained memory functions compared with those with average (p = 0.035) or accelerated decline (p = 0.037). Moreover, separate analyses revealed that DNAm age at follow-up, but not chronologic age, was a significant predictor of dementia (p = 0.019). Our findings suggest that young epigenetic age contributes to maintained memory in aging.
|
|
| 13. |
- Figueira, Joao, et al.
(författare)
-
NMR analysis of the human saliva metabolome distinguishes dementia patients from matched controls
- 2016
-
Ingår i: Molecular Biosystems. - : Royal Society of Chemistry (RSC). - 1742-206X .- 1742-2051. ; 12:8, s. 2562-2571
-
Tidskriftsartikel (refereegranskat)abstract
- Saliva is a biofluid that is sensitive to metabolic changes and is straightforward to collect in a non-invasive manner, but it is seldom used for metabolite analysis when studying neurodegenerative disorders. We present a procedure for both an untargeted and targeted analysis of the saliva metabolome in which nuclear magnetic resonance (NMR) spectroscopy is used in combination with multivariate data analysis. The applicability of this approach is demonstrated on saliva samples selected from the 25 year prospective Betula study, including samples from dementia subjects with either Alzheimer's disease (AD) or vascular dementia at the time of sampling or who developed it by the next sampling/assessment occasion five years later, and age-, gender-, and education-matched control individuals without dementia. Statistically significant multivariate models were obtained that separated patients with dementia from controls and revealed seven discriminatory metabolites. Dementia patients showed significantly increased concentrations of acetic acid (fold change (fc) = 1.25, p = 2 x 10(-5)), histamine (fc = 1.26, p = 0.019), and propionate (fc = 1.35, p = 0.002), while significantly decreased levels were observed for dimethyl sulfone (fc = 0.81, p = 0.005), glycerol (fc = 0.79, p = 0.04), taurine (fc = 0.70, p = 0.007), and succinate (fc = 0.62, p = 0.008). Histamine, succinate, and taurine are known to be important in AD, and acetic acid and glycerol are involved in related pathways. Dimethyl sulfone and propionate originate from the diet and bacterial flora and might reflect poorer periodontal status in the dementia patients. For these seven metabolites, a weak but statistically significant pre-diagnostic value was observed. Taken together, we present a robust and general NMR analysis approach for studying the saliva metabolome that has potential use for screening and early detection of dementia.
|
|
| 14. |
- Figueira, Joao, et al.
(författare)
-
Serum Metabolite Markers of Dementia Through Quantitative NMR Analysis : The Importance of Threonine-Linked Metabolic Pathways
- 2019
-
Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 69:3, s. 763-774
-
Tidskriftsartikel (refereegranskat)abstract
- There is a great need for diagnostic biomarkers of impending dementia. Metabolite markers in blood have been investigated in several studies, but inconclusive findings encourage further investigation, particularly in the pre-diagnostic phase. In the present study, the serum metabolomes of 110 dementia or pre-diagnostic dementia individuals and 201 healthy individuals matched for age, gender, and education were analyzed by nuclear magnetic resonance spectroscopy in combination with multivariate data analysis. 58 metabolites were quantified in each of the 311 samples. Individuals with dementia were discriminated from controls using a panel of seven metabolites, while the pre-diagnostic dementia subjects were distinguished from controls using a separate set of seven metabolites, where threonine was a common significant metabolite in both panels. Metabolite and pathway alterations specific for dementia and pre-diagnostic dementia were identified, in particular a disturbed threonine catabolism at the pre-diagnostic stage that extends to several threonine-linked pathways at the dementia stage.
|
|
| 15. |
- Josefsson, Maria, 1979-, et al.
(författare)
-
Memory profiles predict dementia over 23–28 years in normal but not successful aging
- 2023
-
Ingår i: International psychogeriatrics. - : Cambridge University Press. - 1041-6102 .- 1741-203X. ; 35:7, s. 351-359
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Prospective studies suggest that memory deficits are detectable decades before clinical symptoms of dementia emerge. However, individual differences in long-term memory trajectories prior to diagnosis need to be further elucidated. The aim of the current study was to investigate long-term dementia and mortality risk for individuals with different memory trajectory profiles in a well-characterized population-based sample.Methods: 1062 adults (aged 45–80 years) who were non-demented at baseline were followed over 23–28 years. Dementia and mortality risk were studied for three previously classified episodic memory trajectory groups: maintained high performance (Maintainers; 26%), average decline (Averages; 64%), and accelerated decline (Decliners; 12%), using multistate modeling to characterize individuals’ transitions from an initial non-demented state, possibly to a state of dementia and/or death.Results: The memory groups showed considerable intergroup variability in memory profiles, starting 10–15 years prior to dementia diagnosis, and prior to death. A strong relationship between memory trajectory group and dementia risk was found. Specifically, Decliners had more than a fourfold risk of developing dementia compared to Averages. In contrast, Maintainers had a 2.6 times decreased dementia risk compared to Averages, and in addition showed no detectable memory decline prior to dementia diagnosis. A similar pattern of association was found for the memory groups and mortality risk, although only among non-demented.Conclusion: There was a strong relationship between accelerated memory decline and dementia, further supporting the prognostic value of memory decline. The intergroup differences, however, suggest that mechanisms involved in successful memory aging may delay symptom onset.
|
|
| 16. |
- Kauppi, Karolina, et al.
(författare)
-
Effects of polygenic risk for Alzheimer's disease on rate of cognitive decline in normal aging
- 2020
-
Ingår i: Translational Psychiatry. - : Nature Publishing Group. - 2158-3188. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Most people's cognitive abilities decline with age, with significant and partly genetically driven, individual differences in rate of change. Although APOE 4 and genetic scores for late-onset Alzheimer's disease (LOAD) have been related to cognitive decline during preclinical stages of dementia, there is limited knowledge concerning genetic factors implied in normal cognitive aging. In the present study, we examined three potential genetic predictors of age-related cognitive decline as follows: (1) the APOE 4 allele, (2) a polygenic score for general cognitive ability (PGS-cog), and (3) a polygenic risk score for late-onset AD (PRS-LOAD). We examined up to six time points of cognitive measurements in the longitudinal population-based Betula study, covering a 25-year follow-up period. Only participants that remained alive and non-demented until the most recent dementia screening (1-3 years after the last test occasion) were included (n=1087). Individual differences in rate of cognitive change (composite score) were predicted by the PRS-LOAD and APOE 4, but not by PGS-cog. To control for the possibility that the results reflected a preclinical state of Alzheimer's disease in some participants, we re-ran the analyses excluding cognitive data from the last test occasion to model cognitive change up-until a minimum of 6 years before potential onset of clinical Alzheimers. Strikingly, the association of PRS-LOAD, but not APOE 4, with cognitive change remained. The results indicate that PRS-LOAD predicts individual difference in rate of cognitive decline in normal aging, but it remains to be determined to what extent this reflects preclinical Alzheimer's disease brain pathophysiology and subsequent risk to develop the disease.
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
- Nyberg, Lars, 1966-, et al.
(författare)
-
Biological and environmental predictors of heterogeneity in neurocognitive ageing : Evidence from Betula and other longitudinal studies
- 2020
-
Ingår i: Ageing Research Reviews. - : Elsevier. - 1568-1637 .- 1872-9649. ; 64
-
Forskningsöversikt (refereegranskat)abstract
- Individual differences in cognitive performance increase with advancing age, reflecting marked cognitive changes in some individuals along with little or no change in others. Genetic and lifestyle factors are assumed to influence cognitive performance in aging by affecting the magnitude and extent of age-related brain changes (i.e., brain maintenance or atrophy), as well as the ability to recruit compensatory processes. The purpose of this review is to present findings from the Betula study and other longitudinal studies, with a focus on clarifying the role of key biological and environmental factors assumed to underlie individual differences in brain and cognitive aging. We discuss the vital importance of sampling, analytic methods, consideration of non-ignorable dropout, and related issues for valid conclusions on factors that influence healthy neurocognitive aging.
|
|
| 20. |
- Nyberg, Lars, 1966-, et al.
(författare)
-
Elevated plasma neurofilament light in aging reflects brain white-matter alterations but does not predict cognitive decline or Alzheimer's disease
- 2020
-
Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- IntroductionWe investigated neurofilament light (NFL) accumulation in normal aging as well as in preclinical and clinical Alzheimer's disease (AD) and assessed individual differences in NFL load in relation to cognition and brain white-matter integrity. MethodsWe analyzed longitudinal data covering 30 years (1988-2017). Cognitive testing was done up to six times. Plasma NFL was quantified for controls and 142 cases who developed AD over time, and longitudinal changes in NFL were quantified for 100 individuals with three brain-imaging sessions. ResultsLongitudinal analyses revealed age-related NFL increases with marked variability. AD cases had elevated NFL levels, while no significant group differences were seen in the preclinical phase. Variability in NFL levels showed non-significant correlations with cognition but was associated with brain white matter. DiscussionOur findings suggest that elevated blood NFL, likely reflecting brain white-matter alterations, characterizes clinical AD, while NFL levels do not predict age-related cognitive impairment or impending AD.
|
|
