Differences between Spanish ischemic stroke patients and those from central and northern Europe.: A case-control study

Introduction. Studies conducted in the American population have revealed the existence of differences in cerebral vascular pathologies and in the prevalence of vascular risk factors between races. The few studies carried out in Hispanic populations have found a higher prevalence of diabetes mellitus, as well as a lower frequency of cardioembolic strokes and extracranial carotid atheromatosis, in comparison with whites of Anglo-Saxon extraction. Patients and methods. We performed a case-control study in which one case was paired with two controls, according to age and sex. The cases were people from Central and Northern Europe and the controls were Spaniards. All of them had been admitted to hospital because of ischemic stroke or TIA. We compared the frequency of conventional risk factors (RF), the subtype of ischemic stroke and the results from carotid duplex scans. The odds ratio and confidence intervals (CI) at 95% were calculated for paired data. Results. Arterial hypertension (AHT) was less frequent in the cases, with an OR of 0.45 (CI 0.24-0.83). No statistically significant differences were found in the prevalence of diabetes, hypercholesterolemia, heart disease and atrial fibrillation. Fast recovery stroke and TIA were observed more frequently in the cases than in the controls (OR: 3.73; CI: 1.72-8.07), which we interpreted as being due to a bias in admissions. Carotid duplex scanning revealed stenosis > 70% in 21.9% of the cases and in 13% of the controls. Conclusions. This study did not reveal any differences between Spaniards and Northern Europeans in conventional RF except for a higher prevalence of AHT in Spaniards. Severe carotid pathology seems to be less frequent in Spaniards. Future research should take into account other RFs (such as cholesterol subfractions, homocysteine, etc.), which are possibly race-linked and may account for the differences described.