Size Matters — Obesity Leading Risk Factor for Heart Condition
Reported November 12, 2009
(Ivanhoe Newswire) — Aside from aging itself, obesity appears to be the most powerful predictor of left atrial enlargement (LAE), significantly increasing one’s risk of atrial fibrillation, stroke and death.
Researchers in Lubeck, Germany, found obesity and hypertension to be independent predictors of LAE, both resulting in a variety of structural and functional changes in the heart. The highest measures of left atrial volume (iLA) were seen in obese patients with high blood pressure. This group also had the greatest increase in iLA and the highest incidence of LAE upon follow-up. The effect of obesity was almost twice that of hypertension.
In individuals with high blood pressure, the heart has to deal with greater pressure, which results in a thickening of the walls of the left ventricle. This change also affects the left atrium as the pressure in this chamber ultimately increases as well as resulting in enlargement and loss of function of the atrium.
The mechanisms by which obesity might promote the increased size of the left atrium are seemingly more complex. Obese subjects may undergo dilatation of this chamber because of the cardiac output. The heart of an obese person must transport more blood per minute, which may lead to a volume overload in the left atrium.
In the context of the growing obesity epidemic, authors stress the importance of early assessment and intervention, especially in younger obese patients, to prevent the premature onset of cardiac remodelingchanges in size, shape, and function of the heartresulting from LAE. Authors caution that the extent to which weight management or moderate weight loss can improve LAE remains unclear and needs further investigation.
SOURCE: Journal of the American College of Cardiology, November 17, 2009