Sigurdur Sigurdsson

Dr. Sigurdur Sigurdsson

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Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 June 2009 in JAMA
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Journal Article
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ASAnn I. Scher
Ann I. Scher
LGLarus S Gudmundsson
Larus S Gudmundsson
SSSigurdur Sigurdsson
Sigurdur Sigurdsson
AGAnna Ghambaryan
Anna Ghambaryan
TAThor Aspelund
Thor Aspelund
LLLenore J. Launer
Lenore J. Launer
Migraine, a common neurovascular disorder that affects approximately 11% of adults and 5% of children worldwide, is more common in women than men and is most prevalent in the third and fourth decades of life.1 Although a severe migraine attack is among the most disabling of neurological disorders,2 many individuals with migraine do not consult physicians.3


1 February 2012 in NeuroImage
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Journal Article
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SSSigurdur Sigurdsson
Sigurdur Sigurdsson
TAThor Aspelund
Thor Aspelund
LFLars Forsberg
Lars Forsberg
JFJesper Fredriksson
Jesper Fredriksson
OKOlafur Kjartansson
Olafur Kjartansson
VGVilmundur Gudnason
Vilmundur Gudnason

1 September 2017 in Stroke
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Journal Article
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SSSigurdur Sigurdsson
Sigurdur Sigurdsson
TAThor Aspelund
Thor Aspelund
OKOlafur Kjartansson
Olafur Kjartansson
EGElias Freyr Gudmundsson
Elias Freyr Gudmundsson
MJMaría K. Jónsdóttir
María K. Jónsdóttir
LLLenore J. Launer
Lenore J. Launer
Background and Purpose—: The differentiation of brain infarcts by region is important because their cause and clinical implications may differ. Information on the incidence of these lesions and association with cognition and dementia from longitudinal population studies is scarce. We investigated the incidence of infarcts in cortical, subcortical, cerebellar, and overall brain regions and how prevalent and incident infarcts associate with cognitive change and incident dementia. Methods—: Participants (n=2612, 41% men, mean age 74.6±4.8) underwent brain magnetic resonance imaging for the assessment of infarcts and cognitive testing at baseline and on average 5.2 years later. Incident dementia was assessed according to the international guidelines. Results—: Twenty-one percent of the study participants developed new infarcts. The risk of incident infarcts in men was higher than the risk in women (1.8; 95% confidence interval, 1.5–2.3). Persons with both incident and prevalent infarcts showed steeper cognitive decline and had almost double relative risk of incident dementia (1.7; 95% confidence interval, 1.3–2.2) compared with those without infarcts. Persons with new subcortical infarcts had the highest risk of incident dementia compared with those without infarcts (2.6; 95% confidence interval, 1.9–3.4). Conclusions—: Men are at greater risk of developing incident brain infarcts than women. Persons with incident brain infarcts decline faster in cognition and have an increased risk of dementia compared with those free of infarcts. Incident subcortical infarcts contribute more than cortical and cerebellar infarcts to incident dementia which may indicate that infarcts of small vessel disease origin contribute more to the development of dementia than infarcts of embolic origin in larger vessels.

12 January 2016 in BMC Musculoskeletal Disorders
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HJHelgi Jonsson
Helgi Jonsson
SOSigurbjorg Olafsdottir
Sigurbjorg Olafsdottir
SSSolveig Sigurdardottir
Solveig Sigurdardottir
TAThor Aspelund
Thor Aspelund
GEGudny Eiriksdottir
Gudny Eiriksdottir
VGVilmundur Gudnason
Vilmundur Gudnason
Total joint replacements (TJRs) should be considered as one of few definite endpoints in osteoarthritis research. We analyzed factors associated with late-life prevalence and risk factors for incidence of TJRs due to osteoarthritis in a population based cohort. After exclusion of inflammatory arthritis and fractures as causes of TJR, 5170 participants in the AGES-Reykjavik Study (mean age (SD) 76.4(6), 58 % females) were included for osteoarthritis studies. Three thousand one hundred thirty-three of them had a follow-up visit 5 years later. The prevalence of having at least one joint replacement operation due to OA was 13.6 % and the yearly incidence was 1.4 %/year during the five-year follow-up. Factors positively associated with late life prevalence of TJR included BMI, hand OA severity, female gender, finger length ratio and spine BMD. Risk factors for TJRs in the incidence group were symptoms at initial visit, prior TJR in the contralateral joint and BMI. Much stronger associations were seen for TKR than for THR with discriminatory analysis showing an AUC 0.71 for late life prevalence and 0.84 for the incidence. This study illustrates the importance of the different information expressed by late life prevalence vs. incidence on the factors associated with severe osteoarthritis of the knee and hip. The observation that prior TJR is a risk factor for subsequent TJR in the contralateral joint has not been described previously. The high power predictions for TKR suggest that a predictive model may be feasible, particularly if it can be extended by the addition of further predictive variables, perhaps through genetic, biomarker or imaging data.

2 August 2023 in GeroScience
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Journal Article
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AGApril C E van Gennip
April C E van Gennip
CSClaudia L Satizabal
Claudia L Satizabal
RTRussell P Tracy
Russell P Tracy
SSSigurdur Sigurdsson
Sigurdur Sigurdsson
VGVilmundur Gudnason
Vilmundur Gudnason
TSThomas T van Sloten
Thomas T van Sloten
We investigated the associations of plasma neurofilament light (NfL), glial fibrillary acidic protein (GFAP), and total tau (t-tau) with markers of cerebral small vessel disease (SVD) and with incident dementia. We also investigated whether associations of NfL, GFAP, and t-tau with incident dementia were explained by SVD. Data are from a random subsample (n = 1069) of the population-based AGES-Reykjavik Study who underwent brain MRI and in whom plasma NfL, GFAP, and t-tau were measured at baseline (76.1 ± 5.4 years/55.9% women/baseline 2002–2006/follow-up until 2015). A composite SVD burden score was calculated using white matter hyperintensity volume (WMHV), subcortical infarcts, cerebral microbleeds, and large perivascular spaces. Dementia was assessed in a 3-step process and adjudicated by specialists. Higher NfL was associated with a higher SVD burden score. Dementia occurred in 225 (21.0%) individuals. The SVD burden score significantly explained part of the association between NfL and incident dementia. WMHV mostly strongly contributed to the explained effect. GFAP was not associated with the SVD burden score, but was associated with WMHV, and WMHV significantly explained part of the association between GFAP and incident dementia. T-tau was associated with WMHV, but not with incident dementia. In conclusion, the marker most strongly related to SVD is plasma NfL, for which the association with WMHV appeared to explain part of its association with incident dementia. This study suggests that plasma NfL may reflect the contribution of co-morbid vascular disease to dementia. However, the magnitude of the explained effect was relatively small, and further research is required to investigate the clinical implications of this finding.