Obese Teens May Have Enlarged Hearts

A new study has shown that teenagerswho are obese and overweightmay develop left ventricular hypertrophyand impaired performance of theleft ventricle. Data from 4549 NativeAmericans were used, targeting 460adolescents (245 girls and 215 boys),aged 14 to 20; 27 had hypertension and10 had diabetes. Within this group,24.9% had normal weight, 24.6% wereoverweight, and 48.5% were obese,based on body mass index. Left ventricularenlargement was prevalent in3.5% of the normal-weight teens,12.4% of the overweight teens, and33.5% of the obese teens. The obeseteens also were 4 times more likelythan the normal-weight teens to havean enlarged left ventricular mass. Thisincreased mass is associated withlower ejection fractions, myocardialcontractility, and greater force neededfrom the left atrium to complete fillingof the left ventricle. Also, althoughoverweight and normal-weight teenshad similar metabolic profiles, obeseteens had many of the markers formetabolic syndrome, prompting researchersto suggest that the growthof the left ventricle may be the result of"neurohormonal effects of clusteredmetabolic factors." They noted that,because the results pertain to theNative American population, furtherstudies on other populations are needed.The study results appear in theJune 6, 2006, issue of the Journal of theAmerican College of Cardiology.

Ms. Farley is a freelance medicalwriter based in Wakefield, RI.