Prévalence et répercussions de l’hypertrophie du ventricule gauche chez les enfants obèses

Details

Supervisors

Moniotte, Stéphane ; Beauloye, Véronique

Faculty

Faculté de médecine et médecine dentaire

Degree label

Master [180] en médecine

Abstract

BACKGROUND : The prevalence of overweight and obesity among children has increased dramatically in both developed and developing countries over the last 30 years. Childhood obesity is often accompanied by concomitant cardiovascular abnormalities. Currently, there is no tool to detect the presence of cardiovascular risk factors in children and to predict their association with the risk in adults. OBJECTIVES : The aim of our study was to assess geometric and functional changes of the heart by cardiac echography and RMN in obese compared to nonobese children and adolescents and to examine whether potential alterations could have physical and functional repercussions. METHODS : We prospectively recruited 11 obese children (weight> to +3 standard deviation of the norm) aged 8 to 18 years. The group of obese children was compared to a control group (weight between [-1 and +1] standard deviation of the norm). The control data were obtained retrospectively from the Saint-Luc University Clinics database. Children were assessed by cardiac echo (M-mode and 2D), cardiac RMN, ECG at rest, cardiorespiratory stress test, and a 24-hour ECG Holter. The Ethics Committee approved the study protocol (Approval Number B403201732513). OUTCOMES : The T axis was turned to the left in the obese group on ECG recording. Echocardiography showed higher left ventricular diastolic diameter, telediastolic and telesystolic volumes in the obese group. The increase of left ventricular systolic diameter was almost significant. There were positive relationships between all these parameters and the body mass index SD. Cardiac RMN showed that left ventricular telediastolic volume and left ventricular mass tended to be increased in obese patients compared to the small control group (n = 3-6). This trend persisted after normalization by height. Aditionally, we found a decrease in the right ventricular ejection fraction in obese children while the LV ejection fraction was unchanged. For the cardiorespiratory stress test, basal and maximal systolic blood pressure and maximal diastolic blood pressure were significantly higher in the obese group while maximum oxygen consumption (VO2 MAX) and anaerobic threshold were significantly decreased. During Holter monitoring, SDNN (parameter of the variability of the heart rate) of our obese group was significantly smaller than that of the control group. CONCLUSION: The results of this study demonstrate that childhood obesity is already associated with significant changes in cardiac structure and function, indicating an early onset of potentially unfavourable alterations in the myocardium.