Aerobic Fitness, Physical Activity, and Baroreflex Senstivity in Healthy Adolescents

PURPOSE: To assess the relationship between aerobic fitness, physical activity (PA), and baroreflex sensitivity (BRS) in healthy adolescents. METHODS: Spontaneous BRS was measured for 10 minutes in the supine position using a Continuous Non-Invasive Arterial Pressure Monitor (CNAP) and a 3-lead ECG. Nevrokard Software was used to determine BRS in time and frequency domains. Aerobic fitness was obtained via maximal exercise testing, and peak oxygen uptake (VO2peak) was determined from expired gases. Physical activity was assessed using Kriska's Modifiable Activity Questionnaire (MAQ), determining average total hours (TOT-hrs*wk-1) and average vigorous hours (VIG- hrs*wk-1) per week of PA for the past year. RESULTS: There were 48 healthy subjects (22 males, 18 AA), 14 years of age, who volunteered and were eligible to be included in this analysis. Mean VO2peak was 41.3 ± 10.6 mL*kg-1*min-1, mean TOThrs*wk-1 was 10.1 ± 6.2 hrs*wk-1, and median VIG- hrs*wk-1 was 2.8 hrs*wk-1. Mean BRS was 33.3 ± 14.4ms*mm Hg-1 for time domain and 40.9 ± 18.2 ms*mm Hg-1 for high frequency band. Correlational analysis revealed that aerobic fitness was inversely correlated with BRS in both the time and frequency domains (r= -0.266, p= 0.098, and r= -0.245, p= 0.101), respectively) in the whole group and in males, but not females. A positive correlation was found between total hours of PA and BRS in males only (r= 0.386, p=0.076), but no significant results were found with vigorous hours of PA per week. CONCLUSION: These results do not support beneficial effects of aerobic fitness on BRS. However, of the positive association between PA and BRS suggest a potential way to modify BRS and subsequent risk for developing hypertension in adolescent males.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2011

Author dc:creator

• Dameron, Elizabeth Anne

• adolescents

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/33438

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/33438