Differences in the Nature of Stroke in a Multiethnic Urban South African Population

Abstract

Background and Purpose— The burden of stroke is increasing in Sub-Saharan Africa (SSA) as the population undergoes epidemiological and demographic transition. Little is known about the nature (risk factors, stroke type and subtype, and causes) of stroke in SSA and whether it differs from stroke in high-income populations. We aimed to compare the nature of stroke between black and white populations in South Africa. Methods— We used overlapping sources to ascertain consecutive first-ever-in-a-lifetime stroke patients admitted to Johannesburg Hospital over 23 months. We assessed each patient’s demographic details, risk factors, CT confirmed pathological stroke type, ischemic stroke subtype and stroke severity, and compared the nature of stroke between black and white stroke patients. Results— 524 patients with presumed stroke were referred. Of these, 432 were first-ever strokes; 308 patients were black and 76 white. Black patients were significantly younger (mean age 51) than white patients (61). Stroke severity was similar (median NIH stroke score 10; 95% CI 8 to 11). More black than white patients had cerebral hemorrhage (27% versus 15%), lacunar stroke (28% versus 22%) and total anterior circulation infarcts (28% versus 22%). Large vessel atherosclerosis (none detected) and ischemic heart disease were very uncommon (1%) as a cause of stroke in black patients. Hypertension (70% versus 68%) and diabetes (14 versus 15%) were as common in black and white stroke patients, but mean cholesterol levels were lower (4.6 mmol/L; 95% CI 4.3 to 4.9 versus 5.3 mmol/L; 4.8 to 5.7) and cigarette smoking less frequent in black patients (23 versus 54%). Conclusions— Although this was a hospital-based study, the difference in the nature of stroke between black and white stroke patients likely reflects the profile of stroke risk factors. There is an opportunity to prevent an otherwise inevitable increase in atherosclerotic stroke (and IHD) by targeting dietary and smoking habits in the black South African population.