Associations between systemic and cerebral endothelial impairment determined by cerebrovascular reactivity to L-arginine.

The relationships between cerebral and systemic endothelial (dys)function and between cerebral (dys)function and intima-media thickness (IMT) of carotid arteries in patients and healthy volunteers have not yet been clarified. In order to explore these issues, the authors performed a post hoc correlation analysis of cerebrovascular reactivity to L-arginine, a marker of cerebral endothelial function; flow-mediated dilatation (FMD), a marker of systemic endothelial function; and IMT of the carotid arteries, a marker of the extent of atherosclerosis. Correlations were analyzed in a heterogeneous group consisting of 20 patients with lacunar infarctions (LIs) and extensively impaired endothelial function, 21 patients with similar risk factors (SRs), but without LIs, and 21 healthy controls. Cerebrovascular reactivity to L-arginine was determined by the transcranial Doppler method (TCD), FMD by ultrasound measurements of the brachial artery after hyperemia, and IMT by measurement of the common carotid arteries. Analysis of correlations in the group of 62 subjects revealed that L-arginine reactivity, which was diminished in LI and SR patients, did not correlate with FMD, which was also diminished in both LI and SR patients (Rho = 0.10 with p = 0.458). On the contrary, a significant negative correlation was found between L-arginine reactivity and IMT (Rho = -0.30 with p = 0.015). In conclusion, our study investigating relations between cerebral and systemic endothelial dysfunction showed that cerebral endothelial function, determined by L-arginine reactivity, correlates well with the degree of atherosclerosis determined by IMT but does not correlate with FMD, suggesting that cerebral and systemic endothelial function may not be closely associated.