Downloaded from www.heartmirror.com Heart Mirror Journal Vol. 2, No. 1, 2008 From Affiliated Egyptian Universities and Cardiology Centers ISSN 1687-6652 IntroductIon Obesity and associated metabolic and cardiovascular complications are considered to be major health problems in many societies (1). Obesity is a complex multifactorial chronic disorder, which develops an interaction between the genotypes and the environment (2). Adipose tissue should not be considered as a passive depot for fat but as an active organ in that secretes a variety of molecules including Interleukin -6 “IL-6”, Plasminogen activator inhibitor- 1(PAI-1) as well as Angiotensin II (3). The high incidence of association between obesity and cardiovascular disease has been demonstrated in many studies (4). Framingham heart study (26 years-follow up) suggests that this association is supported by the association between obesity and cluster of metabolic and hemodynamic alterations e.g. dyslipidemia, diabetes mellitus (DM) and hypertension (5). However an issue that remains unclear is whether obesity per se represents an independent cardiovascular risk factor or just a reflection of the associated hypertension, dyslipidemia and metabolic syndrome. Vascular endothelial dysfunction is characterized by imbalance between an endothelium-derived relaxing and contracting factors. Endothelial dysfunction is thought of as the initial step in the pathogenesis of atherosclerosis as well as plaque progression. It also contributes to the disease process in a number of conditions including essential hypertension, DM and congestive heart failure (6). A recent study has documented that the presence of endothelial dysfunction is the pathogenesis of obesity complicated with atherosclerosis, dyslipidemia, DM and hypertension but it has not yet been ORIGINAL ARTICLE Prevalence of Endothelial Dysfunction in Uncomplicated Obesity versus Non- obese Persons: Vascular Ultrasound Study Mohamed Z El Ramly, Yasser M K Baghdady, Hussien H.Kassem, Wael K Mostafa, and M Mohsen Ibrahim Department of Cardiovascular Medicine, Cairo University Background Measurement of endothelial function in patients with atherosclerosis has recently emerged as a useful tool for atherosclerosis research. Recent studies have shown that the severity of endothelial dysfunction relates to the risk for an initial or recurrent cardiovascular event. objective Assess the impact of obesity without associated cardiovascular major cardiovascular risk factors on endothelial dysfunction. Methods 70 healthy individuals of both sexes were included for detection of the prevalence of endothelial dysfunction in obese persons using the non invasive technique of brachial ultrasound. Endothelial functions were assessed by measuring diameter change in response to reactive hyperemia (flow- mediated dilatation FMD) as well as diameter change induced by nitrates (FMD-NTG). results They were divided into two groups: Group 1: Healthy non obese individuals and Group 2: Healthy obese individuals. The mean resting brachial artery diameter "D1" and reactive hyperemia"D2" were 1.314± 0.073 and 0.366±0.028, respectively in non-obese group and 0.355±0.082, and 0.366±0.034 respectively in obese group. The endothelial - independent dilatation was studied after the administration of sublingual nitrates in both groups the second resting brachial artery diameter "D3" and the diameter following the administration of sublingual nitrates "D4" were 0.317±0.035, and 0.39±0.054 respectively in non obese group and 0.353±0.069, and0.39±0.054 respectively in obese group. There was highly significant correlation between both BMI, and W/H ratio (indicators of obesity) with FMD% and FMD-NTG. conclusions Even simple obesity, without associated cardiovascular risk factors, is associated with endothelial dysfunction. Keywords Obesity, endothelium, ultrasound (Heart Mirror J 2008; 2(1): 18-23)