Obesity Enlarges Teenagers' Hearts

A new study warns that the effects of excess weight on heart health can be seen even in adolescence, with abnormal enlargement and impaired pumping function evident in teenagers.

The Strong Heart Study (SHS) is a longitudinal study of cardiovascular risk factors and cardiovascular disease that enrolled 4,549 people in American Indian communities in Arizona, Oklahoma, and North and South Dakota. The analysis included data from examinations of 460 participants aged 14 to 20 years (245 girls and 215 boys). The researchers used ultrasound and other methods to measure the size, shape, and pumping function of the teenagers' hearts. The left ventricles of the hearts of both overweight and obese teenagers were larger and heavier than those of normal-weight participants, but the obese teenagers also showed signs of impaired heart function. The changes were not entirely explained by changes in high blood pressure. The study was published in the June 6, 2006, issue of the Journal of the American College of Cardiology.

"The main findings are that, when obesity is present, something happens in our hearts to increase its size and wall thickness, which cannot be understood by measurement of blood pressure,” said lead author Giovanni de Simone, M.D., of the New York Presbyterian Hospital-Weill Medical College (NY, USA), and the Federico II University Hospital School of Medicine in Naples (Italy). "This excess of cardiac mass, which we call 'inappropriate' in connection to cardiac workload, is also associated with a general impairment of the function of the heart to push blood into the arterial tree and also to distend its cavity to receive the blood returning from the periphery.”

Although the analysis was performed in an American Indian population, the authors believe that these results can be generalized. Similar analyses previously performed in other ethnic groups, such as Caucasians and African Americans, have suggested similar association between left ventricular mass and adiposity, independently of other cardiovascular risk factors.



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New York Presbyterian Hospital-Weill Medical College