Ethnic differences in risk factors for ischemic stroke: a European case-control study.
OBJECTIVE
The aim is to estimate the relative risk and population attributable risk (PAR) of risk factors for ischemic stroke by ethnic group.


METHODS
In this case-control study, cases of first ischemic stroke were taken from the South London Stroke Register and controls from a cross-sectional prevalence survey covering the same area. PAR was determined for each risk factor by ethnic group. Multivariable analysis was used to examine the association between risk factors and ischemic stroke across all ethnic groups.


RESULTS
664 cases and 716 controls aged 45 to 74 years were included, with ethnicity of white 78%:42%, black Caribbean 16%:43%, and black African 6%:15%, respectively. For the white group, high PAR was found for ischemic heart disease (IHD) on ECG (56% [95% CI, 49% to 62%]), obesity (49% [95% CI, 40% to 56%]), hypertension (HT) (38% [95% CI, 29% to 46%]), smoking (31% [95% CI, 19% to 41%]), transient ischemic attack (TIA) (23% [95% CI, 19% to 27%]), and atrial fibrillation (AF) (16% [95% CI, 10% to 21%]). In the black Caribbean compared with the white group, PAR was higher for HT (46% [95% CI, 21% to 63%]) and diabetes mellitus (DM) (29% [95% CI, 14% to 42%]), and lower for current smoking (18% [95% CI, 1% to 32%]) and AF (10% [95% CI, 0% to 18%]). In the black African group HT had a higher PAR (59% [95% CI, 91% to 82%]) than the other groups. PAR for AF (11% [95% CI, -11% to 29%]), obesity (30% [95% CI, -20% to 60%]), and DM (4% [95% CI, -25% to 26%]) was low compared with the other groups. In multivariable analysis, risk factors associated with ischemic stroke included TIA, AF, IHD on ECG, smoking, excess alcohol, obesity, HT, and DM.


CONCLUSIONS
In the first European case-control study examining risk factors for ischemic stroke in black Caribbean and African populations, some differences were demonstrated in the impact of risk factors between these groups. It may be important to address such differences when developing stroke preventative strategies.
Hajat
Cother
C
Department of Public Health Sciences, Guy's, King's, and St Thomas' School of Medicine, Capital House, 42 Weston St, London SE1 3QD, UK. cother.hajat@slpct.nhs.uk
Tilling
Kate
K
Stewart
Judy A
JA
Lemic-Stojcevic
Nada
N
Wolfe
Charles D A
CD
D000368:Aged; D044383:Black People / Q000706:statistics & numerical data; D002545:Brain Ischemia / Q000208:ethnology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008019:Life Style; D016015:Logistic Models; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000208:ethnology*; D044465:White People / Q000706:statistics & numerical data