Stroke epidemiology

Time trends in stroke risk

The Tromsø Study is one of very few epidemiological studies which has been carried out over five decades in a geographically defined area, providing a unique possibility to study time trends in first-ever incident stroke and case fatality. Insights from stroke risks over time which can be compared directly to those arising in the contemporary population are important to understand the shifting factors that influence stroke risk.

We also use data from the Norwegian Stroke Registry to study the risk factors, characteristics and prognosis of wake-up stroke; strokes that occur during sleep.

Principal investigator: Ellisiv B Mathiesen

Social inequality and subtypes of ischemic stroke

A decrease in the age-adjusted stroke incidence has been demonstrated in the Tromsø Study and in many high-income populations in the last decades. Studies of social determinants have repeatedly found socioeconomic inequalities in health. The main aims of this study are 1) to estimate time-trends in incidence of ischemic stroke across socioeconomic level in a general Norwegian population from 1995 and onwards, and 2) to investigate time-trends in incidence of the different subtypes of ischemic stroke in the general population from 1995 an onwards and the impact of risk factors across the different subtypes of ischemic stroke.

Principal investigator: Anne Merete Vangen-Lønne

International collaborations on stroke risk

We take part in large international collaborations aimed at identifying determinants and novel risk factors for stroke:

The Global Cardiovascular Risk Consortium

The BiomarCARE collaboration

External collaborators (Norway): Tom Wilsgaard (UiT), Inger Njølstad (UiT), Maja-Lisa Løchen (UiT), John-Bjarne Hansen (UiT), Sigrid Brækkan (UiT), Ekaterina Sharashova (UiT), Bent Indredavik (St. Olav’s University Hospital and NTNU, Trondheim), Torunn Varmdal (St. Olav’s University Hospital), Hild Fjærtoft (St. Olav’s University Hospital)

Publications:

1. Lindekleiv H, Sandvei MS, Romundstad PR, Wilsgaard T, Njølstad I, Ingebrigtsen T, Vik A, Mathiesen EB. Joint effect of modifiable risk factors on the risk of aneurysmal subarachnoid hemorrhage: a cohort study. Stroke 2012;43:1885-9
2. Sandvei MS, Lindekleiv HM, Romundstad PR, Müller TB, Vatten LJ, Ingebrigtsen T, Njølstad I, Mathiesen EB, Vik A. Risk factors for aneurysmal subarachnoid hemorrhage – body mass index and serum lipids: 11-years follow-up of the HUNT and the Tromsø Study in Norway. Acta Neurol Scand 2012;125:382-388
3. Vangen-Lønne AM, Wilsgaard T, Johnsen SH, Carlsson M, Mathiesen EB. Time trends in incidence and case fatality of ischemic stroke. The Tromsø Study 1977-2010. Stroke 2015;46:1173-9
4. Lindekleiv H, Mathiesen EB, Førde OH, Wilsgaard T, Ingebrigtsen T. Hospital volume and 1-year mortality after treatment of intracranial aneurysms: a study based on patient registries in Scandinavia. J Neurosurg 2015;123:631-7
5. Lappegård J, Ellingsen TS, Skjelbakken T, Mathiesen EB, Njølstad I, Wilsgaard T, Brox J, Brækkan SK, Hansen JB. Red cell distribution width is associated with future risk of incident stroke. The Tromsø Study. Thromb Haemost 2015;115:126-34
6. Sharashova E, Wilsgaard T, Mathiesen EB, Løchen ML, Njølstad I, Brenn T. Resting heart rate predicts incident myocardial infarction, atrial fibrillation, ischaemic stroke and death in the general population: the Tromsø Study. J Epidemiol Community Health 2016;70:902-9
7. Carlsson M, Wilsgaard T, Vangen-Lønne AM, Johnsen SH, Løchen ML, Njølstad I, Mathiesen EB. Temporal trends in incidence and case fatality of intracerebral hemorrhage. The Tromsø Study 1995-2012. Cerebrovasc Dis Extra 2016;6:40-49
8. Tiwari S, Løchen ML, Jacobsen B, Hopstock LA, Nyrnes A, Njølstad I, Mathiesen EB, Schirmer H. CHA2DS2-VASc score, left atrial size and atrial fibrillation as stroke risk factors in the Tromsø Study. BMJ Open Heart, 2016;3:e000439
9. Rinde LB, Småbrekke B, Mathiesen EB, Løchen ML, Njølstad I, Hald EM, Wilsgaard T, Brækkan SK, Hansen JB. Ischemic stroke and risk of venous thromboembolism in the general population: The Tromsø Study. J Am Heart Assoc 2016;5(11). pii: e004311.
10. Vangen-Lønne AM, Wilsgaard T, Johnsen SH, Løchen ML, Njølstad I, Mathiesen EB. Declining incidence of ischemic stroke: What is the impact of changing risk factors? The Tromsø Study 1995-2012. Stroke 2017;48:544-550
11. Vangen-Lønne AM, Ueda P, Gulayin P, Wilsgaard T, Mathiesen EB, Danaei G. Hypothetical interventions to prevent stroke: An application of the parametric g-formula to a healthy middle-aged population. E-pub ahead of print in Eur J Epidemiol 2018 Jan 2, doi: 10.1007/s10654-017-0344-x.
12. Hald EM, Rinde LB, Løchen ML, Mathiesen EB, Wilsgaard T, Njølstad I, Brækkan SK, Hansen JB. Atrial fibrillation and cause-specific risks of pulmonary embolism and ischemic stroke. J Am Heart Assoc 2018;7:e006502
13. Eltoft A, Arntzen KA, Hansen JB, Wilsgaard T, Mathiesen EB, Johnsen SH. Joint effect of carotid plaque and CRP on first-ever ischemic stroke and myocardial infarction? J Am Heart Assoc 2018;7:e008951
14. Carlsson M, Wilsgaard T, Johnsen SH, Johnsen LH, Løchen ML, Njølstad I, Bøgeberg Mathiesen E. The impact of risk factor trends on intracerebral hemorrhage incidence over the last two decades. The Tromsø Study. Int J Stroke 2019;14:61-68
15. Rinde LB, Morelli VM, Småbrekke B, Mathiesen EB, Løchen ML, Njølstad I, Wilsgaard T, Smith E, Rosendaal FR, Frazer KA, Brækkan SK, Hansen JB. Effect of prothrombotic genotypes on the risk of venous thromboembolism in patients with and without ischemic stroke. The Tromsø Study. J Thromb Haemost 2019;17:749-758
16. Hald EM, Løchen ML, Mathiesen EB, Wilsgaard T, Njølstad I, Brækkan SK, Hansen JB. Atrial fibrillation, venous thromboembolism, ischemic stroke and all-cause mortality. The Tromsø Study". Res Pract Thromb Haemost 2020;4(6):1004-101
17. Carlsson M, Wilsgaard T, Johnsen SH, Johnsen LH, Løchen ML, Njølstad I, Mathiesen EB. Long-term survival, causes of death and trends in five-year mortality after intracerebral hemorrhage. The Tromsø Study. Stroke 2021;52:3883-3890
18. Varmdal T, Løchen ML, Wilsgaard T, Njølstad I, Nyrnes A, Grimsgaard S, Mathiesen EB. Data from national health registers as endpoints for the Tromsø Study: Correctness and completeness of stroke diagnoses. Scand J Public Health 2023;51:1042-1049. Epub Jun 14, 201.
19. Rautalin I, Kaprio J, Ingebrigtsen I, Jousilahti P, Løchen ML, Romundstad PR, Salomaa V, Vik A, Wilsgaard T, Mathiesen EB, Sandvei MS, Korja M. Obesity does not protect from subarachnoid hemorrhage – pooled analyses of three large prospective Nordic cohorts. Stroke 2022;53:1301-1309
20. Søyland MH, Tveiten A, Eltoft A, Øygarden H, Varmdal T, Indredavik B, Mathiesen EB. Wake-up stroke and stroke with unknown-onset: occurrence and characteristics from the nationwide Norwegian Stroke Registry. Eur Stroke J 2022;7:143-150
21. Johnsen LH, Vangberg T, Herder M, Ingebrigtsen T, Mathiesen EB. Prevalence of unruptured intracranial aneurysms: impact of different definitions. The Tromsø Study. J Neurol Neurosurg Psychiatry 2022;93:902-907. doi: 10.1136/jnnp-2022-329270.
22. Magnussen C, Ojeda FM, Leong DP, Alegre-Diaz J, Amouyel P, Aviles-Santa L, De Bacquer D, Ballantyne CM, Bernabe-Ortiz A, Bobak M, Brenner H, Can G, Carrillo-Larco RM, de Lemos J, Dobson A, Dörr M, Donfrancesco C, Drygas W, Dullaart RP, Engström G, Ferrario MM, Ferrieres J, de Gaetano G, Goldbourt U, Gonzalez C, Grassi G, Hodge AM, Hveem K, Iacoviello L, Ikram MK, Irazola V, Jobe M, Gousilahti P, Kaleebu P, Kavousi M, Kee F, Khalili D, Koenig W, Kontsevaya A, Kuulasmaa K, Lackner KJ, Leistner DM, Lind L, Linneberg A, Lorenz T, Lyngbakken MN, Malekzadeh R, Malyutina S, Mathiesen EB, Melander O, Metspalu A, Miranda JJ, Moitry M, Mugisha J, Nalini M, Nambi V, Ninomiya T, Oppermann K, d'Orsi E, Pajak A, Palmieri L, Panagiotakos D, Perianayagam A, Peters A, Poustchi H, Prentice AM, Prescott E, Risérus U, Salomaa V, Sans S, Sakata S, Schöttker B, Schutte AE, Sepanlou SG, Sharma SK, Shaw JE, Simons LA, Söderberg S, Tamosiunas A, Thorand B, Tunstall-Pedoe H, Twerenbold R, Vanuzzo D, Veronesi G, Waibel J, Wannamethee SG, Watanabe M, Wild P, Yao Y, Zeng Y, Ziegler A, Blankenberg S, on behalf of the Global Cardiovascular Risk Consortium. Global impact of modifiable risk factors on cardiovascular disease and mortality. N Engl J Med 2023;389:1273-1285