Reduction in Visceral Adiposity is Highly Related to Improvement in Vascular Endothelial Dysfunction among Obese Women Table 2. Pulse Wave Analysis Results Before and After Weight Reduction Variables Baseline AIx (%) AIx NTG (%) AIx Salb (%) Baseline HR (beat/min) HR NTG (beat/min) HR Salb (beat/min) Baseline MAP (mmHg) MAP NTG (mmHg) MAP Salb (mmHg) Before weight reduction (N=36) 22.64 ± 11.25 31.36 ± 9.80 10.03 ± 6.49 71.83 ± 7.95 14.64 ± 11.15 4.19 ± 5.98 89.28 ± 1.14 3.56 ± 0.41 2.00 ± 0.52 After weight reduction (N=36) 22.92 ± 9.09 28.25 ± 11.21 19.33 ± 9.28 70.31 ± 13.55 6.25 ± 25.78 0.81 ± 20.37 86.14 ± 2.41 1.86 ± 2.27 0.36 ± 2.30 p-value 0.859 0.251 <0.001 0.484 0.054 0.329 0.163 0.574 0.991 Values are mean ± SD. AIx, Augmentation Index; AIx-NTG, change in augmentation index by administering nitroglycerin; AIx-Salb, change in augmen- tation index by administering salbutamol; HR, Heart rate; HR-NTG, change in heart rate by administering nitroglycerin; HR-Salb, change in heart rate by administering salbutamol; MAP, mean arterial pressure; MAP-NTG, change in mean arterial pressure by administering nitroglycerin; MAP-Salb, change in mean arterial pressure by administering salbutamol. Table 3. Multiple Regression Analysis of Change in AIx-Salb in Obese Women Obese women (N=36) β p-value Visceral adipose tissue area (cm2) -0.566 <0.001 HOMA score -0.275 0.047 AIx-Salb, change in augmentation index by administering salbutamol; Visceral adipose tissue area, change of visceral adipose tissue area; HOMA, change of homeostasis model assessment score. Changes in heart rate and MAP provoked by the administration of NTG or salbutamol before weight loss were similar to changes after weight reduction (Table 2). Pulse wave analysis combined with provocative pharmacological testing dem- onstrated preserved endothelium-independent vasodilation in healthy premenopausal obese women ( AIx-NTG: 31.36 ± 9.80% before weight reduction vs. 28.25 ± 11.21% after weight reduc- tion, p > 0.05) and an improvement in endothelial- dependent vasodilation following weight reduc- tion ( AIx-Salb: 10.03 ± 6.49% before weight re- duction vs. 19.33 ± 9.28% after reduction, p < 0.001) (Table 2). Relationship between anthropometric and clinico- metabolic parameters and weight reduction Improvements in endothelial-dependent vas- cular function following weight reduction (in- crease in AIx-Salb by weight reduction) were related to reductions in visceral adipose tissue area (r = -0.62, p<0.001), percent body fat (r = -0.35, p < 0.05), BMI (r= -0.33, p<0.05), fasting insulin (r= -0.38, p<0.05), and HOMA scores (r = -0.375, p < 0.05). Moreover, step-wise multiple regression an- alysis identified visceral adipose tissue area (β= -0.57, p < 0.001) as the most significant indepen- dent parameter accounting for improved endo- thelial-dependent vascular function following weight reduction (Table 3). DISCUSSION Obesity is characterized by VED, and the degree of VED is predicted by body fat distribution, independent of metabolic and other hemodynamic parameters.15,16 This association between obesity and VED, an early feature of cardiovascular dis- ease, is of great importance because it may pro- vide clinicians with new preventive strategies against atherosclerosis in obese patients. Recently, a prospective study demonstrated VED improve- ment following substantial weight reduction in postmenopausal obese women with no additional Yonsei Med J Vol. 46, No. 4, 2005