Cand.med Agnethe Eltoft disputerer for ph.d.-graden i helsevitenskap og vil offentlig forsvare avhandlingen:
“C-reactive protein and other circulating biomarkers in carotid atherosclerosis and cardiovascular disease.”
Kort sammendrag av avhandlingen:
Cardiovascular disease (CVD) is the leading cause of death and morbidity worldwide. In Norway there are approximately 13,000 heart attacks and 12,000 strokes each year. Despite the fact that preventive and acute treatment have improved significantly over the last 30 years, CVD rates are expected to increase globally. The traditional risk factors (age, sex, blood pressure, cholesterol, diabetes and smoking) have limited ability to single out individuals at increased risk of CVD. It is therefore important to identify novel markers of disease activity in the preclinical phase which may improve identification of individuals at risk and refine individualized preventive treatment. Atherosclerosis is the underlying cause of most CVD events. Deposits of lipids and inflammation (plaques) in the arteries may rupture and initiate blood clot formation which subsequently occludes arteries and compromises blood flow to organs such as the heart and brain. The degree of atherosclerosis can be measured by ultrasound of the carotid arteries. Previous research indicates that plaques which increase in size pose a higher risk of cardiovascular disease than atherosclerosis that remains stable over time. The aim of this study was to investigate the relationship between the inflammatory marker C-reactive protein (CRP) and other markers in blood with the progression of atherosclerosis, as well as clinical events such as myocardial infarction (MI) and ischemic stroke (IS).
The Tromsø Study is a population-based cohort study where participants have been invited to repeated health surveys. Repeated assessments of traditional risk factors, blood samples and ultrasound of the right carotid artery have been performed in the period 1994-2008. In addition, clinical events such as MI and IS have been recorded. This has given us a unique opportunity to investigate the association between blood markers and the progression of carotid atherosclerosis over time, as well as the association to clinical events.
We found that CRP was associated with the presence of carotid plaque and total plaque area in cross sectional examinations. The associations were strongest in men. CRP did not predict future plaque formation or plaque progression adjusted for traditional risk factors. Both CRP and carotid total plaque area were associated with higher risk of future MI and IS. Individuals who had both elevated CRP and large carotid plaques had highest risk of MI and IS. Carotid ultrasound examination and determination of CRP levels in the blood added predictive value beyond traditional risk factors for identification of individuals with increased CVD risk. The inflammatory cytokine interleukin-6 was associated with plaque progression after six years of follow-up, suggesting that interleukin-6 may be a useful marker to identify patients with unstable plaque in a middle-aged general population.
Veiledere
Hovedveileder førsteamanuensis Stein Harald Johnsen
Biveileder førsteamanuensis Kjell Arne Arntzen
Biveileder professor Ellisiv Bøgeberg Mathiesen
Bedømmelseskomiteen
Professor Ulf Hedin, Department of Vascular Surgery, Karolinska University Hospital, Stockholm, Sverige – 1. opponent
Post. doc Anne Hege Aamodt, Department of Neurology, Oslo universitetssykehus – 2. opponent
Førsteamanuensis Jørgen Gjernes Isaksen, Institutt for klinisk medisin, Det helsevitenskapelige fakultet, UiT Norges arktiske universitet – leder av komité
Disputasleder
Professor Ruth Paulssen, Institutt for klinisk medisin, Det helsevitenskapelige fakultet, UiT Norges arktiske universitet
Prøveforelesning over oppgitt emne holdes kl. 10.15, samme sted: “The value of epidemiologic studies in clinical practice”