Obese children and adolescents show significant adverse alterations in myocardial geometry and function on echocardiography, compared with normal-weight children, according to a report published online Oct. 8 in JACC: Cardiovascular Imaging.
In a prospective, cross-sectional cohort study in Germany, researchers performed two-dimensional echocardiography in 61 obese and 40 nonobese participants aged 8-21 years. All the children were white, free of known disease, and not taking any medications, said Dr. Norman Mangner of the University of Leipzig and Heart Center Leipzig and his associates.
Dr. Norman Mangner
Global ejection fraction was normal in both study groups. However, the obese participants showed thickened LV walls and larger chamber dimensions; as a result, their calculated LV mass and LV mass index were roughly 40% higher than those of nonobese children. Left atrial volume, LA volume index, right atrial area, and right ventricular diameter all were also increased, compared with those of nonobese children. In addition, z scores for LA diameter were above the 95th percentile in a significantly higher percentage of the obese participants (33.3%) than nonobese participants (10%), the investigators said (J. Am. Coll. Cardiol. Img. 2014 Oct. 8 [doi: 10.1016/j.jcmg.2014.08.006]).
Regarding myocardial function, both tissue Doppler-derived peak systolic velocity and deformation in the basoseptal region were reduced in the obese children. Average longitudinal LV strain, strain rate, and displacement – all measures of longitudinal function – were significantly reduced. Average LV circumferential strain was significantly blunted in the obese participants, but the average LV circumferential strain rate and radial function were not significantly different between the two study groups. And diastolic function was decreased in the obese children, as evidenced by their reduced mitral E- to mitral A-wave peak velocity (E/A ratio), reduced mitral annulus tissue Doppler imaging (TDI) peak E-wave velocity, and increased E/E’ ratios.
“It is important to note that [these changes] do not necessarily translate into clinically relevant functional impairment,” Dr. Mangner and his associates said.
A longitudinal study is needed to clarify the clinical significance of these alterations and to explore whether weight loss will reverse them, they added.
This study was supported in part by grants from the German Research Foundation and the Clinical Research Group. One of Dr. Mangner’s associates reported ties to Medtronic, St. Jude Medical, Claret Medical, Boston Scientific, and Edwards; Dr. Mangner and his other associates reported having no financial disclosures.