Resistance training and diastolic myocardial tissue velocities in obese children.

PURPOSE: The primary purpose of this study was to determine the effects of resistance exercise training on early diastolic myocardial velocities (E') in an obese pediatric population. METHODS: Twenty-three obese adolescents were selected to participate in either a resistance-based training program (RT; n = 13, 12.2 +/- 0.4 yr, body mass index [BMI] = 32.5 +/- 1.9 kg m(-2)) or a nonexercise control intervention (n = 10, 13.6 +/- 0.7 yr, BMI = 30.2 +/- 2.6 kg m(-2)) for 8 wk. All subjects had repeated echocardiographic assessments to determine left ventricular (LV) geometry, early transmitral flow velocity (E), and E'. RESULTS: LV mass and wall thicknesses did not significantly change with training or in controls. RT improved E' (11.9 +/- 0.5 to 13.3 +/- 0.5 cm s(-1), P< 0.01) in the presence of a decrease in E/E' (8.17 +/- 0.39 to 7.06 +/- 0.30 cm s(-1), P < 0.01), a marker of left atrial pressure. No changes were evident in the inactive control subjects. CONCLUSIONS: A supervised 8-wk RT exercise program improved early diastolic tissue velocity in obese children, independent of changes in LV morphology.

Impact of obesity on diastolic function in subjects < or = 16 years of age.

The aim of this study was to investigate the impact of obesity on diastolic function in children and adolescents. Echocardiographic measurements were compared in 28 obese subjects (14 males, 14 females) and 15 age- and gender-matched lean controls (8 males, 7 females). Two-dimensional ultrasound imaging, M-mode imaging, and pulse-wave conventional and tissue Doppler measurements were used to assess cardiac structure and function at rest. No differences were evident between lean and obese subjects in age (13.3 +/- 0.5 vs 12.4 +/- 0.4 years), height (163 +/- 4 vs 159 +/- 2 cm), or systolic blood pressure (119 +/- 3 vs 123 +/- 2 mm Hg). Body mass (54.6 +/- 4.0 vs 85.8 +/- 3.6 kg, p < 0.0001) and body mass index (20.5 +/- 0.7 vs 33.3 +/- 1.0 kg/m2, p < 0.00001) were significantly greater in the obese subjects, whereas measurements of wall thickness (interventricular septal wall 0.86 +/- 0.04 vs 0.89 +/- 0.02 cm, posterior wall 0.83 +/- 0.04 vs 0.91 +/- 0.02 cm) and fractional shortening (38.6 +/- 1.2% vs 38.8 +/- 1.2%) did not significantly differ. The E/E' ratio (6.86 +/- 0.20 vs 8.30 +/- 0.32, p < 0.01), E' (13.93 +/- 0.38 vs 12.29 +/- 0.44 cm/s, p < 0.05), the E'/A' ratio (2.49 +/- 0.17 vs 2.05 +/- 0.09, p < 0.05), and the deceleration time of early transmitral blood flow velocity (125.3 +/- 7.7 vs 154.5 +/- 6.8 ms, p < 0.01) were significantly different between the groups, suggesting reduced diastolic function in the obese subjects. In conclusion, these data suggest that indexes of diastolic function, including tissue Doppler measures, are significantly impaired in obese young subjects.