Even modest visceral fat gain causes blood vessel dysfunction

An interesting study just published in the Journal of the American College of Cardiology offers evidence that even a modest amount of fat around your waist prevents blood vessels from dilating properly. But there is good news too. The authors refer to endothelial function (the endothelium is the inner lining of the blood vessel; it regulates constriction and dilation):

"The aim of this study was to determine the impact of fat gain and its distribution on endothelial function in lean healthy humans...Endothelial dysfunction has been identified as an independent predictor of cardiovascular events."

Study subjects were assigned to either gain weight or maintain the same weight while a number of functional indicators were tracked along with body composition. The metric for endothelial function was brachial artery flow-mediated dilation [FMD]. The weight gainers then lost the added weight for the final measurements. What did the data show? First the bad news, then the good:

"FMD decreased in fat gainers but recovered to baseline when subjects shed the gained weight."

Subcutaneous fat gain did not degrade endothelial function. The authors sum up their findings by concluding:

"In normal-weight healthy young subjects, modest fat gain results in impaired endothelial function, even in the absence of changes in blood pressure. Endothelial function recovers after weight loss. Increased visceral rather than subcutaneous fat predicts endothelial dysfunction."

So 'it's not over until the fat lady loses the weight around her waist.'