Thor Aspelund

Thor Aspelund
University of Iceland | HI · Epidemiology and Biostatistics Department of Medicine

PhD

About

638
Publications
100,465
Reads
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47,359
Citations
Introduction
Professor in Epidemiology and Biostatistics at The University of Iceland in the Department of Medicine, Centre of Public Health. PhD in Mathematical Statistics from the University of Iowa, Iowa City in 2002. Interested in clinical prediction models, ROC analysis, survival analysis.
Additional affiliations
June 2015 - present
University of Iceland
Position
  • Professor
January 2011 - June 2015
University of Iceland
Position
  • Professor (Associate)
August 2006 - June 2011
University of Iceland
Position
  • Professor (Associate)
Education
August 1998 - June 2002
University of Iowa
Field of study
  • Statistics
August 1996 - June 1998
University of Iowa
Field of study
  • Statistics
September 1991 - May 1994
University of Iceland
Field of study
  • Mathematics

Publications

Publications (638)
Article
Hair cortisol concentration (HCC) represent a potential biomarker of chronic psychological stress. Previous studies exploring the association between perceived stress and HCC have been limited to relatively small and selected populations. We collected hair samples from 881 women from the Mexican Teachers’ Cohort (MTC) and 398 women from the Iceland...
Article
INTRODUCTION: Educational attainment is related to improved health and longevity. We investigated the relationship between educational attainment and cardiovascular risk factors, subclinical atherosclerosis, and incidence of coronary artery disease. MATERIAL AND METHODS: The Reykjavik REFINE study is a population-based study recruiting 6616 subject...
Preprint
Background The association between cardiovascular disease (CVD) and selected psychiatric disorders has frequently been suggested while inadequate control of familial factors and comorbidities has halted causal inferences. Methods We identified 869 056 patients newly diagnosed with CVD from 1987 to 2016 in Sweden while no history of psychiatric dis...
Preprint
Objectives To study effects of physiotherapist-guided pelvic floor muscle training on pelvic organ prolapse (POP) early postpartum period. Design Assessor-blinded, randomized controlled trial. Setting Physiotherapy Clinic, Reykjavik. Sample Eighty-four primiparous women with a singleton delivery. Methods Participants were screened for eligibility 6...
Article
Full-text available
Age-related macular degeneration (AMD) is one of the most common causes of visual impairment in the elderly, with a complex and still poorly understood etiology. Whole-genome association studies have discovered 34 genomic regions associated with AMD. However, the genes and cognate proteins that mediate the risk, are largely unknown. In the current...
Presentation
Title A clinically validated risk calculator for progression of diabetic retinopathy Purpose: Creation of a smart phone application containing diabetic retinopathy risk calculator to empower individual diabetic patients to understand their personal risk factors and risk profile. Educate and motivate patients to influence these risk factors. Me...
Article
Full-text available
The apolipoprotein E allele 4 (APOE-ε4) is established as a major genetic risk factor for cognitive decline and late-onset Alzheimer’s disease. Accumulating evidence has linked ε4 carriership to abnormal structural brain changes across the adult lifespan. To better understand the underlying causal mechanisms, we investigated the extent to which the...
Article
Full-text available
The main purpose of this research is to analyse school principals’ and teachers’ attitudes towards external school evaluation in Iceland, in particular, the ways in which they consider the evaluation affects their schools’ internal evaluation and drives changes in their own practices. The study uses a quantitative method and is based on a survey co...
Article
Full-text available
Study objectives To date, few studies have assessed sleep problems among women residing in Subarctic regions. Therefore, the aim of this large-scale population-based study was to assess the prevalence of severe sleep problems and associated factors among Icelandic women, living at 63-66°N. Methods Participants were 29,681 women (18-69 years old) w...
Article
Rationale Knowledge on biomarkers of interstitial lung disease is incomplete. Interstitial lung abnormalities (ILA) are radiologic changes that may present in its early stages. Objectives To uncover blood proteins associated with ILA using large-scale proteomics methods. Methods Data from two prospective cohort studies, the AGES-Reykjavik study (n=...
Article
Full-text available
Background Long-term mental and physical health consequences of COVID-19 (long COVID) are a persistent public health concern. Little is still known about the long-term mental health of non-hospitalised patients with COVID-19 with varying illness severities. Our aim was to assess the prevalence of adverse mental health symptoms among individuals dia...
Article
Full-text available
Background: Childhood abuse and neglect have been associated with premenstrual disorders (PMDs), including premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). However, the associations of other adverse childhood experiences (ACEs) and the cumulative number of ACEs with PMDs remain to be explored. Methods: To evaluate the asso...
Article
Full-text available
PurposeTo study whether dietary patterns in adolescence are associated with risk of colorectal cancer (CRC).Methods Food frequency data were obtained from the AGES-Reykjavik study, conducted between 2002 and 2006, which included 5,078 (58% women) participants with mean age of 77 (± 5.8) years. Principal component analysis was used to identify dieta...
Article
Background: The COVID-19 pandemic and efforts to contain it have substantially affected the daily lives of most of the world's population. Objective: We describe the impact of the first COVID-19 wave and associated social restrictions on the mental health of a large adult population. Methods: We performed a cohort study nested in a prospective...
Article
Full-text available
Background: Adverse childhood experiences (ACEs) have consistently been associated with elevated risk of multiple adverse health outcomes, yet their contribution to coping ability and psychiatric resilience in adulthood is unclear. Methods: Cross-sectional data were derived from the ongoing Stress-And-Gene-Analysis cohort, representing 30% of th...
Article
Full-text available
Circulating proteins can be used to diagnose and predict disease-related outcomes. A deep serum proteome survey recently revealed close associations between serum protein networks and common disease. In the current study, 54,469 low-frequency and common exome-array variants were compared to 4782 protein measurements in the serum of 5343 individuals...
Article
Full-text available
With the growing number of genetic association studies, the genotype-phenotype atlas has become increasingly more complex, yet the functional consequences of most disease associated alleles is not understood. The measurement of protein level variation in solid tissues and biofluids integrated with genetic variants offers a path to deeper functional...
Article
Background and aims Coronary artery calcium (CAC) and carotid plaque are markers of atherosclerosis and predict future coronary heart disease (CHD) events. The aim of this study was to investigate associations between CAC and carotid plaque in asymptomatic individuals, also in relation to predicted CHD-risk and incident events. A secondary aim was...
Article
Purpose Creation of a smart phone application containing diabetic retinopathy risk calculator to empower individual diabetic patients to understand their personal risk factors and risk profile. Educate and motivate patients to influence these risk factors. Methods A previously validated and published diabetic retinopathy risk algorithm (Aspelund e...
Article
Full-text available
Purpose The aim of this study was to assess the role of the patient’s background and perceived healthcare-related factors in symptoms of acute stress after lung cancer diagnosis. Methods The study population consisted of 89 individuals referred for diagnostic work-up at Landspitali National University Hospital in Iceland and subsequently diagnosed...
Article
Background Women are exposed to a variety of life stressors, particularly violence, during their lifetime which increases the risk of developing various psychiatric and somatic diseases, with dysregulated secretion of cortisol as one potential biological mechanism. We examined the association between violence and other life stressors and hair corti...
Preprint
Full-text available
BACKGROUND The aim of this multinational study was to assess the development of adverse mental health symptoms among individuals diagnosed with COVID-19 in the general population by acute infection severity up to 16 months after diagnosis. METHODS Participants consisted of 247 249 individuals from seven cohorts across six countries (Denmark, Estoni...
Article
Excessive daytime sleepiness includes both an inability to stay awake during the day and a general feeling of sleepiness. We describe different dimensions of daytime sleepiness in adults with moderate–severe obstructive sleep apnea (OSA) before and after 2 years of positive airway pressure (PAP) treatment. Using the Epworth Sleepiness Scale (score...
Article
Background and Purpose Studies on the association of cerebrovascular risk factors to magnetic resonance imaging detected brain infarcts have been inconsistent, partly reflecting limits of assessment to infarcts anywhere in the brain, as opposed to specific brain regions. We hypothesized that risk-factors may differ depending on where the infarct is...
Article
Full-text available
Key features COVIDMENT [www.covidment.is] is a NordForsk-funded research collaboration across six nations, with the overarching aim to significantly advance current knowledge on mental morbidity trajectories associated with the coronavirus disease 2019 (COVID-19) in the general population and in specific risk groups. From March 2020 through Augus...
Article
Background Smoldering multiple myeloma (SMM) is an asymptomatic precursor condition to multiple myeloma (MM). Emerging data from clinical trials indicate that - compared to watchful monitoring - initiation of therapy at the SMM stage might be indicated. Currently, there is no established screening for SMM in the general population and therefore pat...
Article
Growth rate is regulated by hormonal pathways that might affect early cancer development. We explored the association between rate of growth in height from age 8 to 13 (childhood) years and from age 13 to height at study entry (adolescence), and risk of breast and prostate cancer. Participants were 2,037 Icelanders born 1915 - 1935, who took part i...
Article
Full-text available
Background Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. Methods We used data from 1990 to 2019 on people aged 30...
Preprint
Full-text available
Age-related macular degeneration (AMD) is one of the most frequent causes of visual impairment in the elderly population. The overall etiology of AMD is complex and still poorly understood, though age, obesity, smoking, and high-density lipoprotein are known risk factors. In one of the first successful reported genome-wide association studies (GWAS...
Preprint
Full-text available
Adverse childhood experiences (ACEs) have consistently been associated with elevated risk of multiple adverse health outcomes, yet their contribution to coping ability and psychiatric resilience in adulthood is unclear. Participants were 19,613 women in the Icelandic Stress-And-Gene-Analysis cohort with complete data on 13 ACEs measured with the AC...
Preprint
Full-text available
With the growing number of genetic association studies, the genotype-phenotype atlas has become increasingly more complex, yet the functional consequences of most disease associated alleles is not understood. The measurement of protein level variation in solid tissues and biofluids integrated with genetic variants offers a path to deeper functional...
Article
Full-text available
The shocking severity of the Covid-19 pandemic has woken up an unprecedented interest and accelerated effort of the scientific community to model and forecast epidemic spreading to find ways to control it regionally and between regions. Here we present a model that in addition to describing the dynamics of epidemic spreading with the traditional co...
Article
Full-text available
Objective: To test if patients recovering from COVID-19 are at increased risk of mental morbidities and to what extent such risk is exacerbated by illness severity. Design: Population-based cross-sectional study. Setting: Iceland. Participants: A total of 22 861 individuals were recruited through invitations to existing nationwide cohorts an...
Article
Full-text available
PurposeTo study changes in lung function among individuals with a risk of obstructive sleep apnoea (OSA), and if asthma affected this relationship.Methods We used data from the European Community Respiratory Health Survey II and III, a multicentre general population study. Participants answered questionnaires and performed spirometry at baseline an...
Article
Introduction and hypothesis: To study the prevalence of pelvic floor dysfunction and related bother in primiparous women 6-10 weeks postpartum, comparing vaginal and cesarean delivery. Methods: Cross-sectional study of 721 mothers with singleton births in Reykjavik, Iceland, 2015 to 2017, using an electronic questionnaire. Information on urinary...
Article
Introduction: The number of people with type 2 diabetes has increased in Iceland in the last few decades. We utilized the national database on prescribed medication from the Directorate of Health to estimate the prevalence and incidence of type 2 diabetes in Iceland and made prediction on the prevalence of type 2 diabetes in Iceland in 10 and 20 y...
Article
Full-text available
The 2014–15 Holuhraun eruption in Iceland was the largest fissure eruption in over 200 years, emitting prodigious amounts of gas and particulate matter into the troposphere. Reykjavík, the capital area of Iceland (250 km from eruption site) was exposed to air pollution events from advection of (i) a relatively young and chemically primitive volcani...
Article
Objective Monoclonal gammopathy of undetermined significance (MGUS) is the asymptomatic precursor of multiple myeloma (MM). Lytic bone lesions and fractures are hallmarks of MM and although there are no lytic lesions in MGUS, it has also been associated with fractures. The causes of fractures in MGUS are currently unclear but potential causes inclu...
Article
Introduction Melatonin levels are partially driven by the parenchyma volume of the pineal gland. Low urinary levels of 6‐sulfatoxymelatonin have been associated with increased risk of advanced prostate cancer, but the relationship between pineal gland volume and composition and prostate cancer risk has not been examined. Materials and Methods We u...
Article
Background Smartphones present a near-ubiquitous channel through which structured lifestyle change can reduce risk or progression of the most common noncommunicable diseases. We explored whether a digital structured lifestyle program enhances weight loss. Methods We randomized overweight and obese participants attending a four-month lifestyle chan...
Article
Full-text available
From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in di...
Article
Full-text available
From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in di...
Article
Objective: To describe the prevalence of diffuse idiopathic skeletal hyperostosis (DISH) in a large population-based study of elderly Icelanders, with particular reference to weight-related factors and the metabolic syndrome. Method: The study population comprised 5321 participants aged 68–96 years (2276 males, mean ± sd age 76 ± 5 , and 3045 femal...
Article
Objective This study aimed to investigate how skeletal muscle attenuation and adipose tissue (AT) attenuation of the quadriceps, hamstrings, paraspinal muscle groups and the psoas muscle vary according to the targeted muscles, sex, and age. Design Population-based cross-sectional study. Setting Community-dwelling old population in Reykjavik, Icel...
Article
Objective This study aimed to examine whether an accelerated decline in quadriceps cross-sectional area (CSA), attenuation (a surrogate of quality), and strength, as well as lower limb muscular function, are associated with hip fractures in older adults with impaired kidney function. Design Prospective population-based study. Setting Community-dw...
Article
Full-text available
Background: The Holuhraun volcanic eruption September 2014 to February 2015 emitted large amounts of sulfur dioxide (SO2). The aim of this study was to determine the association between volcanic SO2 gases on general population respiratory health some 250 km from the eruption site, in the Icelandic capital area. Methods: Respiratory health outcom...
Article
High proportion of patients with multiple myeloma suffer from comorbidities which may alter clinical management. Therefore, our aims were to evaluate the prevalence of comorbidities and their impact on survival. We included patients diagnosed with multiple myeloma 1990 ‐ 2013 in Sweden and all diagnoses from each patient from 1985. A total of 13,65...
Article
Full-text available
Objective As severity of outcome in COVID‐19 is disproportionately higher among individuals with obesity, smokers, patients with hypertension, kidney disease, chronic pulmonary disease, coronary heart disease (CHD), and/or type 2 diabetes (T2D), serum levels of ACE2, the cellular entry point for the coronavirus SARS‐CoV‐2, were examined in these hi...
Article
Objective Opportunistic infections in chronic lymphocytic leukemia (CLL) have been described in clinical trials, single‐center studies, and case reports. We performed a nationwide study to estimate the incidence and impact of inpatient opportunistic infections. Methods The incidence rate (IR) and incidence rate ratio (IRR) for Swedish CLL patients...
Article
Full-text available
Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled ana...
Presentation
A SMART PHONE APP FOR INDIVIDUAL RISK ASSESSMENT FOR PROGRESSION OF DIABETIC RETINOPATHY PURPOSE Creation of a smart phone application containing diabetic retinopathy risk calculator to empower individual diabetic patients to understand their personal risk factors and risk profile. Educate and motivate patients to influence these risk factors. M...
Article
Full-text available
Aim. Creation of a smart phone application containing diabetic retinopathy risk calculator to empower individual diabetic patients to understand their personal risk factors and risk profile. Educate and motivate patients to influence these risk factors. Materials and methods. A previously validated and published diabetic retinopathy risk algorithm...
Poster
Title A SMART PHONE APP FOR INDIVIDUAL RISK ASSESSMENT FOR PROGRESSION OF DIABETIC RETINOPATHY PURPOSE Creation of a smart phone application containing diabetic retinopathy risk calculator to empower individual diabetic patients to understand their personal risk factors and risk profile. Educate and motivate patients to influence these risk factor...
Preprint
Full-text available
Background The Holuhraun volcanic eruption September 2014 to February 2015 emitted large amounts of sulfur dioxide (SO2). The aim of this study was to determine the association between volcanic SO2 gases on general population respiratory health some 250 km from the eruption site, in the Icelandic capital area. Methods Respiratory health outcomes we...
Preprint
Full-text available
Background The Holuhraun volcanic eruption September 2014 to February 2015 emitted large amounts of sulfur dioxide (SO2). The aim of this study was to determine the association between volcanic SO2 gases on general population respiratory health some 250 km from the eruption site, in the Icelandic capital area. Methods Respiratory health outcomes w...
Preprint
Full-text available
Over the past two decades there has been a number of global outbreaks of viral diseases. This has accelerated the efforts to model and forecast the disease spreading, in order to find ways to confine the spreading regionally and between regions. Towards this we have devised a model of geographical spreading of viral infections due to human spatial...
Article
An increased incidence of lung cancer is well-known among patients with idiopathic pulmonary fibrosis. It is unknown whether interstitial lung abnormalities, early fibrotic changes of the lung, are a risk factor for lung cancer in the general population. The study's objective was to assess whether interstitial lung abnormalities were associated wit...
Article
Objective Infections in chronic lymphocytic leukemia (CLL) have been thoroughly investigated in the setting of clinical trials and single center studies. However, large cohort studies on real‐world data and studies on temporal trends are lacking. We performed a nationwide study on serious bacterial infections in CLL. Methods Using high‐quality Swe...
Preprint
Full-text available
Aims: Severity of outcome in COVID-19 is disproportionately higher among the obese, males, smokers, those suffering from hypertension, kidney disease, coronary heart disease (CHD) and/or type 2 diabetes (T2D). We examined if serum levels of ACE2, the cellular entry point for the coronavirus SARS-CoV-2, were altered in these high-risk groups. Method...
Article
Full-text available
High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world³ and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein...
Preprint
Full-text available
Importance Recent reports have shown that hypertension is the most common comorbidity associated with mortality in the current coronavirus disease 2019 (COVID-19). This has been related to the use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) as animal studies indicate that these medications increas...
Article
The increasing prevalence of type 2 diabetes poses a major challenge to societies worldwide. Blood-based factors like serum proteins are in contact with every organ in the body to mediate global homeostasis and may thus directly regulate complex processes such as aging and the development of common chronic diseases. We applied a data-driven proteom...
Preprint
Full-text available
Circulating proteins are prognostic for human outcomes including cancer, heart failure, brain trauma and brain amyloid plaque burden. A deep serum proteome survey recently revealed close associations of serum protein networks and common diseases. The present study reveals unprecedented number of individual serum proteins that overlap genetic signat...
Article
Full-text available
Die diabetische Retinopathie ist weltweit eine der Hauptursachen für eine Erblindung im erwerbsfähigen Alter. Diese schwerwiegende Erkrankung zeigt normalerweise keine Symptome in den frühen Stadien, was bedeutet, dass sich der Patient häufig schon in einem fortgeschrittenen Stadium der Erkrankung befindet, wenn Symptome wahrnehmbar werden und er i...
Article
Purpose To test in a ‘real world’ diabetic eye‐screening programme, a computer‐based personal risk evaluation for progression to sight‐threatening diabetic retinopathy. Screening intervals were individualized, and clinical outcomes, safety and cost‐effectiveness documented. Methods The RETINARISK algorithm was used in an ophthalmology clinic in No...
Article
Full-text available
Osteoarthritis is an increasingly important health problem for which the main treatment remains joint replacement. Therapy developments have been hampered by a lack of biomarkers that can reliably predict disease, while 2D radiographs interpreted by human observers are still the gold standard for clinical trial imaging assessment. We propose a 3D a...