Coronary endothelial function is directly related to extent of weight loss in obese patients

Background Obesity is a risk factor for future cardiovascular events. [1] Prior studies have shown that weight loss is related to improved peripheral vascular function.[2] However, the relationship of weight loss to coronary endothelial function, which is impaired in early atherosclerosis and predicts future cardiovascular events,[3] is not completely understood. By means of previously described noninvasive MRI methods combined with isometric handgrip to assess endothelial-dependent coronary vasoreactivity,[4]4 we tested the hypothesis that weight loss over six months is associated with better coronary endothelial function (EndoFx) in obese, non-diabetic individuals. Methods Eighteen overweight and obese non-diabetic adults defined as BMI >25 (BMI=32.3±4.4, age=54.2±8.1 years, mean ±SD) with no history of cardiovascular disease underwent a six month diet and exercise weight loss regimen. At the end of the study period, participants were imaged using a 3T MRI scanner (Achieva,Philips,Best,NL) and a 32-element cardiac coil for signal reception(Figure 1). To measure EndoFx, spiral coronary MRI was performed before and during continuous isometric handgrip exercise, an endothelial-dependent stressor.[5] Coronary cross-sectional area (CSA) and coronary blood velocity (CV) changes were measured, and coronary blood flow (CBF)