| 1. |
- Byberg, Liisa, et al.
(författare)
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Prediction of fracture risk in men : A cohort study
- 2012
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 27:4, s. 797-807
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Tidskriftsartikel (refereegranskat)abstract
- FRAX is a tool that identifies individuals with high fracture risk who will benefit from pharmacological treatment of osteoporosis. However, a majority of fractures among elderly occur in people without osteoporosis and most occur after a fall. Our aim was to accurately identify men with a high future risk of fracture, independent of cause. In the population-based Uppsala Longitudinal Study of Adult Men (ULSAM) and using survival analysis we studied different models' prognostic values (R(2) ) for any fracture and hip fracture within 10 years from age 50 (n = 2322), 60 (n = 1852), 71 (n = 1221), and 82 (n = 526). During the total follow-up period from age 50, 897 fractures occurred in 585 individuals. Of these, 281 were hip fractures occurring in 189 individuals. The rates of any fracture were 5.7/1000 person-years at risk from age 50 and 25.9/1000 person-years at risk from age 82. Corresponding hip fractures rates were 2.9 and 11.7/1000 person-years at risk. The FRAX model included all variables in FRAX except bone mineral density. The full model combining FRAX variables, comorbidity, medications, and behavioral factors explained 25-45% of all fractures and 80-92% of hip fractures, depending on age. The corresponding prognostic values of the FRAX model were 7-17% for all fractures and 41-60% for hip fractures. Net reclassification improvement (NRI) comparing the full model with the FRAX model ranged between 40 and 53% for any fracture and between 40 and 87% for hip fracture. Within the highest quintile of predicted fracture risk with the full model, 1/3 of the men will have a fracture within 10 years after age 71 years and 2/3 after age 82 years. We conclude that the addition of comorbidity, medication and behavioral factors to the clinical components of FRAX can substantially improve the ability to identify men at high risk of fracture, especially hip fracture.
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| 2. |
- Degerman Gunnarsson, Malin, et al.
(författare)
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Pittsburgh compound-B and Alzheimer's disease biomarkers in CSF, plasma and urine: An exploratory study.
- 2010
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Ingår i: Dementia and geriatric cognitive disorders. - Basel : S. Karger AG. - 1421-9824 .- 1420-8008. ; 29:3, s. 204-12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The positron emission tomography (PET) radiotracer Pittsburgh Compound-B (PIB) is an in vivo ligand for measuring beta-amyloid (Abeta) load. Associations between PET PIB and cerebrospinal fluid (CSF) Abeta1-42 and apolipoprotein E epsilon4 (APOE epsilon4) have been observed in several studies, but the relations between PIB uptake and other biomarkers of Alzheimer's disease (AD) are less investigated. METHOD: PET PIB, PET 18Fluoro-2-deoxy-D-glucose and different AD biomarkers were measured twice in CSF, plasma and urine 12 months apart in 10 patients with a clinical diagnosis of mild to moderate AD. RESULTS: PIB retention was constant over 1 year, inversely related to low CSF Abeta1-42 (p = 0.01) and correlated positively to the numbers of the APOE epsilon4 allele (0, 1 or 2) (p = 0.02). There was a relation between mean PIB retention and CSF ApoE protein (r = -0.59, p = 0.07), and plasma cystatin C (r = -0.56, p = 0.09). CONCLUSION: PIB retention is strongly related to CSF Abeta1-42, and to the numbers of the APOE epsilon4 allele.
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| 3. |
- Degerman Gunnarsson, Malin, et al.
(författare)
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Re-Evaluation of Clinical Dementia Diagnoses with Pittsburgh Compound B Positron Emission Tomography
- 2013
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Ingår i: Dementia and Geriatric Cognitive Disorders Extra. - Basel : S. Karger. - 1664-5464. ; 3:1, s. 472-481
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: There is an overlap regarding Pittsburgh compound B (PIB) retention in patients clinically diagnosed as Alzheimer's disease (AD) and non-AD dementia. The aim of the present study was to investigate whether there are any differences between PIB-positive and PIB-negative patients in a mixed cohort of patients with neurodegenerative dementia of mild severity regarding neuropsychological test performance and regional cerebral glucose metabolism measured with [18F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET). Methods: Eighteen patients clinically diagnosed as probable AD or frontotemporal dementia were examined with PIB PET, FDG PET and neuropsychological tests and followed for 5-9 years in a clinical setting. Results: The PIB-positive patients (7 out of 18) had slower psychomotor speed and more impaired visual episodic memory than the PIB-negative patients; otherwise performance did not differ between the groups. The initial clinical diagnoses were changed in one third of the patients (6 out of 18) during follow-up. Conclusions: The subtle differences in neuropsychological performance, the overlap of hypometabolic patterns and clinical features between AD and non-AD dementia highlight the need for amyloid biomarkers and a readiness to re-evaluate the initial diagnosis.
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| 4. |
- Degerman Gunnarsson, Malin, et al.
(författare)
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High Tau Levels in Cerebrospinal Fluid Predict Rapid Decline and Increased Dementia Mortality in Alzheimer's Disease
- 2014
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 37:3-4, s. 196-206
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Cerebrospinal fluid (CSF) amyloid beta(42) (A beta(42)), total tau (t-tau) and phosphorylated tau (p-tau) are useful as predictors of conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia. However, results are contradictory as to whether these biomarkers reflect the future rate of clinical decline. Methods: This is a retrospective study on 196 patients with AD [mild/moderate AD (n = 72) or AD-MCI (n = 124) at baseline] with a follow-up period of 2-9 years' duration (median 6 years). Lumbar punctures were performed at baseline as a part of the diagnostic procedure. Results: We found an increased risk of rapid cognitive decline defined as a drop in the Mini-Mental State Examination score of = 4 points/year in patients with CSF t-tau concentrations above the median (OR 3.31, 95% CI 1.53-7.16) and CSF p-tau above the median (OR 2.53, 95% CI 1.21-5.26). Patients with CSF t-tau in the highest quartile had a higher risk of dying in severe dementia (HR 4.67, 95% CI 1.16-18.82). Conclusions: In this large AD cohort, we found an association between high levels of CSF t-tau and p-tau and a more aggressive course of the disease, measured as a rapid cognitive decline and a higher risk of dying in severe dementia.
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| 5. |
- Benedict, Christian, et al.
(författare)
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The fat mass and obesity gene is linked to reduced verbal fluency in overweight and obese elderly men
- 2011
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 32:6, s. 1159.e1-1159.e5
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Tidskriftsartikel (refereegranskat)abstract
- Humans carrying the prevalent rs9939609 A allele of the fat mass and obesity-associated (FTO) gene are more susceptible to developing obesity than noncarries. Recently, polymorphisms in the FTO gene of elderly subjects have also been linked to a reduced volume in the frontal lobe as well as increased risk for incident Alzheimer disease. However, so far there is no evidence directly linking the FTO gene to functional cognitive processes. Here we examined whether the FTO rs9939609 A allele is associated with verbal fluency performance in 355 elderly men at the age of 82 years who have no clinically apparent cognitive impairment. Retrieval of verbal memory is a good surrogate measure reflecting frontal lobe functioning. Here we found that obese and overweight but not normal weight FTO A allele carriers showed a lower performance on verbal fluency than non-carriers (homozygous for rs9939609 T allele). This effect was not observed for a measure of general cognitive performance (i.e., Mini-Mental State Examination score), thereby indicating that the FTO gene primarily affects frontal lobe-dependent cognitive processes in elderly men.
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| 6. |
- Degerman Gunnarsson, Malin, 1969-
(författare)
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Biomarkers as Monitors of Drug Effect, Diagnostic Tools and Predictors of Deterioration Rate in Alzheimer’s Disease
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Decreased amyloid-ß42 (Aß42), increased total tau (t-tau) and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF) reflect histopathological core changes in the most common dementia disorder, Alzheimer’s disease (AD). They discriminate AD from healthy controls and predict conversion to AD with a relatively high accuracy. Memantine, an uncompetitive NMDA-receptor antagonist, is indicated for symptomatic treatment of AD. The first aim of this thesis was to investigate effects of memantine on CSF concentrations of Aβ42, tau and p-tau. Secondly, the aim was to explore the relation between these CSF biomarkers and retention of the amyloid biomarker Pittsburgh compound B using positron emission tomography (PIB PET), regional glucose metabolism measured with 18Fluoro-2-deoxy-d-glucose (FDG) PET and neuropsychological test performance. The third aim was to investigate their possible utility as predictors of future rate of AD dementia deterioration. All patients in the studies were recruited from the Memory Clinic, Uppsala University Hospital. In study I CSF p-tau concentrations in 11 AD patients were reduced after twelve months treatment with memantine, indicating that this compound may affect a key pathological process in AD. Results from study II showed that the concentrations of CSF Aß42 are lower in PIB+ patients than in PIB- patients, and that the PIB retention was stable during 12 months. In study III 10 patients with the diagnoses AD (6 PIB+/4 PIB-) and 8 subjects (1 PIB+/7 PIB-) with frontotemporal dementia were included. PIB+ patients had lower psychomotor speed measured by performance on the Trail Making Test A and impaired visual episodic memory compared to the PIB- patients. The initial clinical diagnoses were changed in 33% of the patients (6/18) during follow-up. Study IV is the first-ever report of an association between high CSF tau and dying in severe dementia. These 196 AD patients were followed up to nine years after baseline lumbar puncture. Moreover, CSF t-tau concentrations above median was associated with an increased risk of rapid cognitive decline (OR 3.31 (95% CI 1.53-7.16), independently of baseline functional stage. Thus, a clear association between high levels of CSF t-tau and p-tau and a more aggressive course of the disease was shown.
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| 7. |
- Sundelöf, Johan, 1974-
(författare)
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Amyloid β-protein, Cystatin C and Cathepsin B as Biomarkers of Alzheimer's Disease
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- It is suggested that Alzheimer’s disease (AD) is caused by an imbalance between production, degradation and clearance of the amyloid-β (Aβ) protein. This imbalance leads to aggregation of Aβ and tau proteins and neurodegeneration in the brain. Today there is increasing evidence that the balance between the protease cathepsin B and the protease inhibitor cystatin C affects the tendency for Aβ to aggregate. The primary aim of this thesis was to investigate Aβ, cystatin C and cathepsin B levels in blood and cerebro-spinal fluid (CSF) in relation to the risk of AD.Studies I & II were based on the re-examinations of participants, at ages 70 and 77, in the Uppsala Longitudinal Study of Adult Men (ULSAM), a community-based prospective study initiated in 1970 (participants then being 50 years of age). In ULSAM, low plasma Aβ1-40 (Study I) and low serum cystatin C levels (Study II) were associated with a higher risk of AD. Studies III & IV were based on a cross-sectional sample of people with AD, mild cognitive impairment and healthy controls, recruited at three Swedish Memory Disorder units: Uppsala University Hospital, Uppsala, Skåne University Hospital, Malmö, and Karolinska University Hospital, Huddinge, Stockholm. In Study III, CSF cystatin C levels were positively correlated with both Aβ1-42 and tau levels. In Study IV, individuals with AD had higher mean plasma cathepsin B levels than healthy controls.In conclusion, low plasma Aβ1-40 and low serum cystatin C levels may precede clinically manifest AD in elderly men, cystatin C levels are positively correlated with Aβ1-42 and tau levels in CSF, and mean plasma cathepsin B levels are higher in people with AD compared to healthy controls. In addition to Aβ1-42 and tau levels in CSF, Aβ1-40, cystatin C and cathepsin B levels in blood may reflect the risk of AD.
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