Relationship Between Body Fat And Cardiorespiratory Responses In African American Adolescents

Abstract

Obesity is prevalent in every age group in the American society and this is true for adolescents. Excess body weight increases the risk of numerous diseases, particularly cardiovascular disease, cancer, and diabetes in the adult population. Adolescent's obesity impact on pathological diseases is yet to be determined. The degree to which obesity is associated with decrements in other bodily functions is unclear. PURPOSE The purpose of this study was to evaluate the relationship between body fat and cardiorespiratory variables in African American teenagers. METHODS Subjects included Sixty-five (N=65) teenagers with a mean age 15, SD 1.2 yrs for 32 boys and 33 girls who were assessed for forced vital capacity (FEV1) systolic (SBP) and diastolic blood pressures (DBP), resting heart rate (RHR) and heart rate (HR) responses during a three minute step test (ST). The participants were considered to have high fat levels (HF) if their body fat was greater than 25% fat (girls, N = 17, body fat 35.4%, wt 79.1 kg; boys N = 8, body fat 31.8%, wt 82.5 kg) and average body fat levels (AF) if body fat was less than 25% (girls, N=16, body fat 22.1%, wt 55.2 kg; boys N = 24, body fat 15.0%, wt 64.2 kg). Statistical analysis included mean scores for all measures and a T-test was performed to establish differences based on body fat level and gender. Significance was set a priori at p < 0.05. RESULTS The HF girls had higher blood pressure values than the AF girls (SBP mmHg - 127 vs. 112 and DBP mmHg - 65 vs 74, respectively, but were not significantly different on the other variables. The HF boys had a significantly higher DBP mmHg (80 vs. 70) and three minute heart rate (bpm) response during the step test (176 vs. 163) than the AF boys, but were not significantly different on the other variables. CONCLUSIONS These data indicate that high fat levels result in elevated cardiorespiratory values and suggest that HF adolescents may become more prone to cardiovascular diseases. The HF girls were pre-hypertensive for SBP and the HF boys were also pre-hypertensive for DBP. For definitive evidence, long term follow-up is required to determine the effects of adolescent obesity on adult disease pathology