Markers of Cardiovascular Risk, Insulin Resistance, and Ventricular Dysfunction and Remodeling in Obese Adolescents

Abstract

To test our hypothesis that obese adolescents have left ventricular (LV) dysfunction and remodeling that are associated with markers of cardiovascular risk and insulin resistance (IR). In a cross-sectional study of 44 obese and 14 lean age-, sex-, Tanner stage-, and race-matched adolescents, IR, markers of cardiovascular risks, conventional and 2-dimensional speckle tracking echocardiography measures of LV function and structure were evaluated and compared. The obese adolescents had significantly increased body mass index Z-score, systolic blood pressure, fasting insulin, IR, and atherogenic lipids compared with the lean adolescents. A subgroup of obese adolescents had LV remodeling characterized by significantly increased LV mass index (g/m(2.7)) and relative wall thickness. Almost all obese adolescents had LV dysfunction with peak LV global longitudinal strain (GLS, %), systolic GLS rate (GLSR, %/s), and early diastolic GLSR significantly lower than in lean adolescents and in the normal pediatric population. Body mass index Z-score predicted LV remodeling (LV mass index [R(2)=0.34] and relative wall thickness [R(2) 0.10]), and peak LV GLS (R(2) 0.15), and along with systolic blood pressure, predicted systolic GLSR (R(2) 0.16); (P≤.01 for all). Fasting insulin predicted early diastolic GLSR (R(2) 0.17, P≤.01). Obese adolescents have subclinical ventricular dysfunction associated with the severity of obesity, increased systolic blood pressure, and IR. Ventricular remodeling is present in a subgroup of obese adolescents in association with the severity of obesity. These findings suggest that obesity may have an early impact on the cardiovascular health of obese adolescents.