الفهرس 
ENDOTHELIAL FUNCTIONOnly 14 pages are availabe for public view
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Abstract
Hypertension is a major public health problem that affects 20% of the adult population worldwide. It is a major risk factor for cardiovascular disease, contributing greatly to morbidity and mortality from stroke, myocardial infarction, end-stage renal disease, and congestive heart failure.
The prevalence of hypertension rises with age and affects 25-30% of the entire adult population, reaching up to 60-70% of individuals beyond the seventh decade.
The current definition of hypertension adopts a blood pressure threshold of 140/90 mmHg. In patients with diabetes mellitus and chronic renal disease, a blood pressure below the threshold of 130/80 mmHg is the preferred goal.
JNC7 guidelines was the first to introduce in 2003 a recent blood pressure category “prehypertension” which is numerically detected as (SBP 120-139 mmHg or DBP 80-90 mmHg).
The Trial of Preventing Hypertension (TROPHY) was an investigator-initiated study to examine whether early treatment of prehypertension, defined for this study as systolic pressure of 130 to 139 mm Hg and diastolic pressure of 89 mm Hg or lower and systolic pressure of 139 mm Hg or lower and diastolic pressure of 85 to 89 mm Hg, might prevent or delay the development of subsequent incident hypertension.
The endothelium is the monolayer of endothelial cells lining the lumen of all blood vessels. Functioning as a protective biocompatible barrier between all tissues and the circulating blood.
Endothelial dysfunction is a marker for increased cardiovascular risk.
Endothelial function is often quantified by flow-mediated dilation (FMD), which represents the endothelium-dependent relaxation of a conduit artery-typically the brachial artery – due to an increased blood flow. Brachial artery reactivity is a frequently used non-invasive ultrasonographic assessment of FMD that indicates endothelium-dependent response to shear stress.
Impaired endothelial function is recognized as an early and modulating process in the pathophysiology of atherosclerotic cardiovascular disease and correlates with impaired endothelium-dependent relaxation in the coronary arteries.
The study was conducted to assess the brachial artery flow mediated dilation measured by high-resolution 2D ultrasound in prehypertensive volunteers.
The study was conducted in Elagosa Police Hospital, cardiology department, and included 200 volunteers, 150 as prehypertensive group and 50 as control group who were subjected to endothelial function test.
For whom, proper history taking and thorough clinical examination were done. High-frequency ultrasonographic imaging of the brachial artery to assess endothelium-dependent flow-mediated vasodilation (FMD) was done.
The study showed that 85 of the study subjects (42.50%) with abnormal endothelial function, 115 of the study subjects (57.50%) with normal endothelial function.
The correlation between the endothelial function and SBP, DBP and MBP of prehypertension was assessed.
All the results were analyzed statistically to detect their significance.
The study showed that abnormal endothelial function was more prevalent in prehypertensive group (53.33%) than in normal group (10.00%).
The study showed that there was no significant correlation between the abnormal endothelial function and SBP, DBP and MBP of prehypertension.
It is concluded that prehypertension appears to have moderate effect on endothelial function in conduit artery.
These observations may suggest difference in endothelial susceptibility to the effects of hypertension, and there are many other methods rather than brachial artery flow_mediated vasodilation in assesment of endothelial function that could be studied in comparison to our method:
• Positron emission tomography.
• Brachial artery catheterization with venous occlusive plethysmography.
• Vascular tonometry and measurments of vascular stiffness.
• Inflammatory markers such as CRP and adhesion molecules as ICAM-1.
Alarger study including another groups with different degree of hypertension is suggested; which would be of an additional value to these results.