Differences in endothelial function and vascular reactivity between Scottish and Arabic populations

Background: The endothelium is a major organ that plays a central role in the regulation of blood flow, resists thrombus formation and maintains blood fluidity. Environmental, dietary, but also genetic factors might affect endothelial cell function and vascular activity. Methods and Results: Endothelium-dependent and -independent vascular responses were evaluated in 42 male subjects from two different populations: 30 Scottish and 12 Arabic (transient visitors to UK) (20-41 years old). Endothelium-dependent and -independent vascular responses were measured in the forearm skin using laser Doppler imaging after iontophoresis of increasing doses of acetylcholine and sodium nitroprusside, respectively. Endothelium-dependent responses were significantly greater in Arabic subjects compared with responses in Scottish subjects (mean ACh ratio 4.9 ± 1.2 v 3.8 ± 1.5, respectively, P = 0.013, ANOVA). Although there was no significant difference between the groups in endothelium-independent vascular responses (mean SNP ratio 3.4 ± 1.2 v 2.8 ± 1.2, respectively, P = 0.26, ANOVA), there was a trend however towards a higher peak SNP response in the Arabic group (5.3 ± 1.5 v 4.1 ± 1.9, respectively, P = 0.019). Conclusions: These results suggest that a significant difference exists in the endothelial function and vascular reactivity between these populations. Although the reasons for these differences are not clear, they may be related to differences in life styles, tradition, food intake, environmental and genetic factors.