engleski

Influence of High Salt Diet on Microvascular Reactivity in Young Healthy Female Human Subjects

Increase in salt intake significantly alters vascular reactivity to different physiological stimuli. However, the effects of high salt (HS) intake on microvascular endothelial response in healthy young people without pre-existing conditions such as diabetes and hypertension are still unknown. The aim was to assess effects of acute salt loading on microvascular reactivity to reactive hyperemia in young healthy women, using non-invasive Laser Doppler Flowmetry (LDF). Circulating concentration of cell adhesion molecules (CAMs): ICAM, VCAM and E-selectin, as indicators of endothelial function were measured. Eleven normotensive women (21±3 years) were instructed to maintain a low-salt (LS) diet (less than 40 mmol Na/daily) during 7 days and simultaneously divided into HS group (N=5) (intake of 200 mmol Na/daily) or placebo group (N=6). LDF was performed before and after salt diet protocol as measurement of relative changes in blood flow after 1- and 2-minute occlusion. In the HS group there was a statistically significant decrease in microvascular reactivity after 1-minute occlusion (endothelium-dependant mechanisms) with no difference after a 2-minute occlusion (maximum dilation ability), before and after HS diet. Concentration of VCAM was significantly decreased after HS salt diet with no difference in concentrations of other CAMs. The increased urinary volume, decreased urinary sodium, and increased urinary potassium concentration in subjects on LS diet, and increased urinary sodium concentration in subjects on HS diet confirmed consistency of experimental protocol and subjects’ adherence to diet. Although plasma renin activity and serum aldosterone concentration decreased in HS diet and increased in women on LS diet, they didn’t reach statistical significance. This study shows that even 1 week of HS intake may have negative effect on vascular reactivity, decreasing blood flow in reactive hyperemia by affecting endothelial function, as shown in decreased levels of VCAM. Increased number of subjects in further study is needed.

microcirculation; endothelium; laser doppler flowmetry

DOI: 10.1159/000321436. Svi sazeci sa Skupa objavljeni su u Kidney & blood pressure research (ISSN 1423-0143) 30 (2007) (1) ISBN 978-3-8055-8396-1.