Abstract 14542: Increased Left Atrial Dimension in Adolescent Obesity Not Solely Due to Left Ventricular Hypertrophy
Background: Obesity affects 18% of US adolescents and is associated with increased cardiac risk. Markers of cardiac functioning associated with increased risk include left ventricular mass index (LVMI) and left atrial dimension (LAD).
Aim: We propose to compare these markers of cardiac functioning in obese adolescents with a parallel age matched, non-obese cohort with known aortic stenosis (AS).
Methods: A retrospective chart review was performed of 1901 adolescents, age 12-18 years (mean age 14.86 yrs), who had a transthoracic echocardiogram; 1545 subjects classified as non-obese normals, 321 subjects as obese (BMI percentile≥95%) normals, and 35 subjects with peak aortic valve flow velocity (pAOVfv) greater than 2 m/sec with normal BMI (AS). Subjects with both AS and obesity were excluded. LAD, height-based LVMI (LV mass/ht^2.7), and pAOVfv were obtained. The relationships between these cardiac measures and BMI in non-AS subjects were examined.
Results: (see accompanying table) LAD, LVMI, and pAOVfv are independently correlated with BMI for obese and normals. LVMI was significantly larger in the obese and AS groups than normals, with no difference between obese and AS. The pAOVfv was higher in AS subjects than in obese and normals. The obese group also had higher pAOVfv than normals. LAD was larger in the obese than either non-obese group, with no significant difference in LAD between the non-obese groups.
Conclusions: We conclude that obesity in adolescence is associated with increased LVMI comparable to that seen with mild AS and an increased LAD which is not seen in the age matched AS cohort. This suggests that the LVH in obesity differs from that seen in AS, with impairment of LV compliance in obese subjects versus subjects with AS resulting in higher LA pressure and LA enlargement. Risk for cardiac disease is even higher for these youth than previously believed, underscoring the need for urgent treatment and further investigation for risk management.
- © 2010 by American Heart Association, Inc.