Myocardial function, mechanics and work by echocardiography in adolescents with severe obesity

Obesity and its metabolic complications can impact the heart's structure and function in childhood, although demonstrating this impact has been challenging. New echocardiographic parameters such as left atrial strain (LAε) and left ventricular strain (LVε), as well as myocardial work (MW), could reveal subclinical alterations in cardiac function.

The aim is to evaluate the feasibility of these parameters in adolescents with severe obesity and explore their associations with body fat, metabolic comorbidities, and physical capacity.

This is a cross-sectional study in adolescents with obesity who underwent echocardiography with analysis of LAε, LVε and MW using speckle tracking. Feasibility and association with anthropometry, body fat percentage, comorbidities and cardiopulmonary test were analyzed.

Twenty adolescents were recruited, 13 (65%) were males, median age 14.2 (interquartile range: 12.9-14.9) years old. The median Z-score for BMI (zBMI) was +3.03 (2.87-3.14), 14 (70%) had severe obesity (zBMI ≥+3), 12 (60%) body fat ≥95^th percentile, 9 (45%) high blood pressure (HBP) and 8 (40%) metabolic syndrome. The analysis of the echocardiographic parameters was feasible in 95% (LAε) and 100% (LVε and MW). LVε was lower in adolescents with vs. without metabolic syndrome: 17.8% (17.5-19.3%) vs. 19.3% (18.3-20.3%), P = 0.046; and with vs. without HBP 17.8% (17.5-18.6%) vs. 19.7% (18.4-20.3%), P = 0.02. Those with body fat ≥95^th percentile had lower LAε and MW parameters, without association with cardiopulmonary test.

Echocardiographic evaluation of LAε, LVε and MW is feasible in adolescents with severe obesity. A higher proportion of body fat and the presence of comorbidities are associated with alterations in these new echocardiographic functional parameters suggesting myocardial impact of higher metabolic compromise.