Received February 22, 2007
Revised March 23, 2007
Accepted after revision April 27, 2007

¹ University of Maryland
² Department of Kinesiology, University of Maryland, College Park, MD
³ Howard University

^* To whom correspondence should be addressed. E-mail: jennifer.jones{at}utsouthwestern.edu.

	Abstract

Aldosterone influences the kidney's regulation of blood pressure (BP), but aldosterone can contribute to hypertension pathogenesis. BP is reduced with aerobic exercise training (AEX), but the extent to which plasma aldosterone (PA) levels change is unclear. The purpose was to determine whether 6 mo of AEX changed PA levels, 24-hour sodium (Na+) excretion and BP in prehypertensives and hypertensives and whether these changes differed by ethnicity. The study was performed in the Kinesiology Department at the University of Maryland, College Park and 35 (22 White, 13 African American (AA)) sedentary prehypertensives and hypertensives completed 6 mo of AEX. Blood samples were collected under fasting and supine conditions and PA was measured by RIA. AEX increased maximal oxygen consumption (24±0.8 vs. 28±1, p<0.001) decreased PA levels (97±11 vs. 72±6 pg/ml, p=0.01), body mass index (28±6 vs. 27±6, p=0.004) and weight (85±2 vs. 83±2, p=0.003). AEX decreased PA levels (119±16 to 81±7 pg/ml, p=0.02) in the Whites but there was no change in BP and Na+ excretion. AA participants had no significant changes in PA levels, BP and Na+ excretion. PA levels were 47% lower at baseline (p=0.01) and 30% lower after AEX (p=0.04) in AA participants compared to Whites. Baseline (p=0.08) and final (p=0.16) PA levels no longer differed between the two groups after accounting for baseline and final intra-abdominal fat, respectively. The reduction in PA levels with AEX appeared to be driven by the change in PA levels in White participants. Fat distribution contributed to the ethnic differences in PA levels. Key Words: Aldosterone, Blood Pressure, Exercise and Ethnicity

Key Words: Blood pressure, Exercise