Clinical research: metabolic syndrome, dyslipidemia, and vascular abnormalities
Exercise training normalizes vascular dysfunction and improves central adiposity in obese adolescents

https://doi.org/10.1016/j.jacc.2004.01.032Get rights and content
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Abstract

Objectives

We sought to characterize the impact of obesity on vascular function in adolescents and to determine whether an exercise program reverses abnormalities in endothelial function.

Background

Obesity, a major modifiable risk factor for cardiovascular disease, is epidemic in Western societies, with rapid rates of increase in the young. Atherosclerosis begins in childhood, and endothelial dysfunction is its earliest detectable manifestation.

Methods

The influence of eight weeks of circuit training (CT) was examined in 19 obese subjects (14.3 ± 1.5 years), using a randomized, crossover protocol. Functional capacity and muscular strength were assessed by standard techniques. Body composition was examined using anthropometric measures and dual-energy X-ray absorptiometry. Conduit vessel endothelial function was assessed using high-resolution ultrasound and flow-mediated dilation (FMD) of the brachial artery.

Results

Circuit training decreased abdominal and trunk fat and significantly improved fitness and muscular strength (p < 0.05). In the obese group, FMD was significantly impaired relative to control subjects (n = 20) at entry (5.3 ± 0.9% vs. 8.9 ± 1.5%, p < 0.05) and was normalized after CT (8.8 ± 0.8%, p < 0.05).

Conclusions

Circuit training improved functional capacity, muscular strength, and body composition in obese adolescents. Furthermore, conduit vessel function was normalized after exercise training. If vascular dysfunction is an integral component of the pathogenesis of vascular disease, this study supports the value of an exercise program in the management of obese adolescents.

Abbreviations

BMI
body mass index
BP
blood pressure
CT
circuit training
DEXA
dual-energy X-ray absorptiometry
FMD
flow-mediated dilation
HbA1c
glycosylated hemoglobin
HDL
high-density lipoprotein
HR
heart rate
LDL
low-density lipoprotein
NO
nitric oxide

Cited by (0)

This study was supported by the National Heart Foundation of Australia. Drs. Beye and Siafarikas received a Novo Nordisk Fellowship.