Yonsei Medical Journal Vol. 46, No. 4, pp. 511 - 518, 2005 Reduction in Visceral Adiposity is Highly Related to Improvement in Vascular Endothelial Dysfunction among Obese Women: An Assessment of Endothelial Function by Radial Artery Pulse Wave Analysis Si-Hoon Park1 and Kyung Won Shim2 1Department of Cardiology and Ewha Medical Research Institute, College of Medicine, Ewha Womans University, Seoul, Korea; 2Department of Family Medicine, College of Medicine, Ewha Womans University, Seoul, Korea. Because obesity is frequently complicated by other cardio- vascular risk factors, the impact of a reduction in visceral adiposity on vascular endothelial dysfunction (VED) in obese patients is difficult to determine. In the present study, we evaluated the impact of a reduction in visceral adiposity on VED in obese women. Thirty-six premenopausal obese women (BMI 25 kg/m2) without complications were enrolled in the study. VED was evaluated by determining the augmentation index (AIx) from radial artery pulse waves obtained by appla- nation tonometry. Changes in AIx in response to nitroglycerin- induced endothelium-independent vasodilatation ( AIx-NTG) and in response to salbutamol administration ( AIx-Salb) were determined before and after weight reduction. After a 12-week weight reduction program, the average weight loss was 7.96±3.47 kg, with losses of 21.88± 20.39 cm2 in vis- ceral fat areas (p < 0.001). Pulse wave analysis combined with provocative pharmacological testing demonstrated preserved endothelium-independent vasodilation in healthy premenopaus- al obese women ( AIx-NTG: 31.36±9.80% before weight re- duction vs. 28.25 ± 11.21% after weight reduction, p > 0.1) and an improvement in endothelial-dependent vasodilation fol- lowing weight reduction ( AIx-Salb: 10.03±6.49% before weight reduction vs. 19.33 ± 9.28% after reduction, p < 0.001). A reduction in visceral adipose tissue was found to be most significantly related to an increase in AIx-Salb (β= -0.57, p < 0.001). A reduction in visceral adiposity was significantly related to an improvement in VED. This finding suggests that reduction of visceral adiposity may be as important as the control of other major risk factors in the prevention of atherosclerosis in obese women. Received January 19, 2005 Accepted April 21, 2005 Reprint address: requests to Dr. Kyung Won Shim, Department of Cardiology and Ewha Medical Research Institute, Ewha Womans University College of Medicine, Mokdong Hospital, 911-1 Mok-dong, Yangcheon-gu, Seoul 158-710, Korea. Tel: 82-2-2650-5309, Fax: 82-2-2650-5424, E-mail: sihoon@ewha.ac.kr Key Words: Augmentation index, visceral adiposity, vascular endothelial dysfunction INTRODUCTION Obesity is an independent risk factor for cardio- vascular disease.1,2 In particular, abdominal vis- ceral adipose tissue is believed to have harmful effects on vascular endothelial function through various interactions of coagulants and inflamma- tory molecules.3 The vascular endothelium serves as an endocrine organ, secreting several vasoactive substances, such as nitric oxide. These substances prevent the development of atheroma. Obesity is independently associated with vascular endothe- lial dysfunction (VED,) and VED is a key event in the early development of atherosclerosis. Therefore, VED may be an important link between obesity and atherosclerosis. Weight reduction has been re- ported to improve VED.4 However, because obesity is frequently accompanied by other cardiovascu- lar risk factors and metabolic diseases, the ability of reduced visceral adiposity alone to improve VED in obese patients has been difficult to determine. A simple, non-invasive pulse wave analysis base technique was recently used to evaluate va- somotor endothelial function.5,6 After demonstra- ting that albuterol,7 a β2 -agonist, reduces wave reflection by activating the L-arginine-NO path- way, many studies have shown that an assess- ment of global endothelial function can be per- formed by examining changes in the peripheral Yonsei Med J Vol. 46, No. 4, 2005