Intracranial arterial stenosis in Ecuadorian Natives/Mestizos. A population-based study in older adults (The Atahualpa Project).

BACKGROUND: Intracranial arterial stenosis (IAS) is more prevalent among Asians, Blacks and Caribbean Hispanics than in Whites. However, there is no information on the importance of this common cause of stroke among Mestizo/Native populations of Latin America. We aimed to assess prevalence and correlates of IAS in an indigenous Ecuadorian population of older adults. METHODS: Atahualpa residents aged ≥60 years were identified during door-to-door surveys and invited to undergo brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of intracranial vessels for identification of stroke lesions and arterial stenosis. Prevalence of IAS was assessed in patients with strokes as well as in stroke-free individuals. A logistic regression model was constructed with stroke as the outcome, IAS as the exposure, and confounders (demographics and cardiovascular risk factors) as independent variables. RESULTS: Out of 267 participants (mean age 71 ± 8 years, 57% women), 15 (5.6%) had intracranial arterial stenosis, including 10 out of 52 (19.2%) persons with stroke and five out of 215 (2.3%) without. The multivariate logistic regression model showed significant association of IAS with stroke after adjusting for demographics and cardiovascular risk factors (OR: 7.9, 95% C.I.: 2.2-27.8, p=0.001). Mechanisms underlying stroke in patients with IAS included perforator occlusion, artery-to-artery embolism and hypoperfusion. CONCLUSIONS: Prevalence of IAS in Ecuadorian Natives/Mestizos is similar to that in Asians. Individuals aged ≥60 years with IAS are almost eight times more likely to have a stroke after adjusting for confounding variables.

Metabolic syndrome is associated with intracranial large artery disease among ethnic Chinese patients with stroke.

BACKGROUND: The association of metabolic syndrome (MetS) and intracranial large artery disease (ICLAD) has been described, but only in cohorts of ethnic Korean patients with stroke. We investigated the relationship of MetS and ICLAD among ethnic Chinese patients. METHODS: This is a prospective study of consecutive ethnic Chinese patients with acute ischemic stroke living in Singapore. ICLAD was diagnosed on transcranial color-coded Doppler or magnetic resonance angiography. RESULTS: Among the 135 patients studied, the frequency of MetS was higher among patients with ICLAD (39% v 16%, P = .003). This association was independent of age, hypertension, and diabetes (P = .003), and individual MetS criteria (P = .004). The prevalence of ICLAD positively correlated with the number of MetS criteria fulfilled (P = .021). CONCLUSIONS: Our findings of an association between MetS and ICLAD among ethnic Chinese patients with stroke concur with findings among ethnic Korean patients. This validation provides a basis for further investigation into the pathophysiologic link between MetS and ICLAD.