Risk Factor Characterization of Ischemic Stroke Subtypes Among West Africans
Authors: Sarfo Fred S. , Ovbiagele Bruce , Akpa Onoja , Akpalu Albert , Wahab Kolawole , Obiako Reginald , Komolafe Morenikeji , Owolabi Lukman , Ogbole Godwin , Calys-Tagoe Benedict , Fakunle Adekunle , Sanni Taofeek , Mulugeta Gebregziabher , Abdul Salaam , Akintunde Adeseye A. , Olowookere Samuel , Uvere Ezinne O. , Ibinaiye Philip , Akinyemi Joshua , Uwanuruochi Kelechukwu , Olayemi Balogun , Odunlami Olufemi A. , Abunimye Esther , Arulogun Oyedunni , Isah Suleiman Y. , Abubakar Sani A. , Oladimeji Adebayo , Adebayo Philip , Shidali Vincent , Chukwuonye Innocent I. , Akpalu Josephine , Tito-Ilori Moyinoluwalogo M. , Asowata Osahon J. , Sanya Emmanuel O. , Amusa Ganiyu , Onyeonoro Ugochukwu , Ogunmodede James A. , Sule Abdullateef G. , Akisanya Cynthia , Mensah Yaw , Oyinloye Olalekan I. , Appiah Lambert , Agunloye Atinuke M. , Osaigbovo Godwin O. , Olabinri Eunice , Kolo Philip M. , Okeke Obiora , Adeoye Abiodun M. , Ajose Olabamiji , Jenkins Carolyn , Lackland Daniel T. , Egberongbe Adedeji A. , Adeniji Olaleye , Ohifemen Adeleye Osimhiarherhuo , Tiwari Hemant K. , Arnett Donna , Laryea Ruth Y. , Olunuga Taiwo , Akinwande Kazeem S. , Imoh Lucius , Ogah Okechukwu S. , Melikam Ezinne S. , Adebolaji Adeyemo , Oguike Wisdom , Ogunronbi Olumayowa , Adeniyi Wasiu , Olugbo Obiabo Y. , Bello Abiodun H. , Ohagwu Kenneth A. , Ogunjimi Luqman , Agyekum Francis , Iheonye Henry , Adesina Julius , Diala Samuel , Dambatta Hamisu A. , Ikubor Joyce , Singh Arti , Adamu Sheila , Obese Vida , Adusei Nathaniel , Owusu Dorcas , Ampofo Michael , Tagge Raelle , Efidi Richard , Fawale Bimbo , Yaria Joseph , Akinyemi Rufus , Owolabi Mayowa ,   on behalf of SIREN
Published: September 2021

Background and Purpose:
To identify the qualitative and quantitative contributions of conventional risk factors for occurrence of ischemic stroke and its key pathophysiologic subtypes among West Africans.

Methods:
The SIREN (Stroke Investigative Research and Educational Network) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with ischemic stroke who were etiologically subtyped using the A-S-C-O-D classification into atherosclerosis, small-vessel occlusion, cardiac pathology, other causes, and dissection. Controls were age- and gender-matched stroke-free adults. Detailed evaluations for vascular, lifestyle, and psychosocial factors were performed. We used conditional logistic regression to estimate adjusted odds ratios with 95% CI.

Results:

There were 2431 ischemic stroke case and stroke-free control pairs with respective mean ages of 62.2±14.0 versus 60.9±13.7 years. There were 1024 (42.1%) small vessel occlusions, 427 (17.6%) large-artery atherosclerosis, 258 (10.6%) cardio-embolic, 3 (0.1%) carotid dissections, and 719 (29.6%) undetermined/other causes. The adjusted odds ratio (95% CI) for the 8 dominant risk factors for ischemic stroke were hypertension, 10.34 (6.91–15.45); dyslipidemia, 5.16 (3.78–7.03); diabetes, 3.44 (2.60–4.56); low green vegetable consumption, 1.89 (1.45–2.46); red meat consumption, 1.89 (1.45–2.46); cardiac disease, 1.88 (1.22–2.90); monthly income $100 or more, 1.72 (1.24–2.39); and psychosocial stress, 1.62 (1.18–2.21). Hypertension, dyslipidemia, diabetes were confluent factors shared by small-vessel, large-vessel and cardio-embolic subtypes. Stroke cases and stroke-free controls had a mean of 5.3±1.5 versus 3.2±1.0 adverse cardio-metabolic risk factors respectively (
P
<0.0001).

Conclusions:
Traditional vascular risk factors demonstrate important differential effect sizes with pathophysiologic, clinical and preventative implications on the occurrence of ischemic stroke among indigenous West Africans.