Role of potassium excretion and percent body fat on ethnic differences in plasma aldosterone levels.
OBJECTIVE
To determine whether plasma aldosterone (PA) levels differed between African American and White prehypertensives and if so, could the difference be explained by ethnicity-related variability in urinary K+ and Na+ excretion, body mass index (BMI), and percent body fat.


METHODS
Ethnic comparison


METHODS
The University of Maryland College Park and the University of Maryland School of Pharmacy.


METHODS
61 (African American, n=28; White, n=33) prehypertensives (systolic blood pressure [SBP] 131 +/- 10 mm Hg, diastolic blood [DBP] 85 +/- 6 mm Hg).


METHODS
6-week dietary stabilization and medication tapering period.


METHODS
PA levels, Na+ and K+ excretion, blood pressure, and percent body fat and BMI.


RESULTS
We saw no differences in SBP (P=.36) and DBP (P=.54) between the two ethnic groups. PA levels were lower in African Americans compared to Whites (62 +/- 7 vs 107 +/- 12 pg/mL, P=.002). 24-hour K+ excretion was lower among African Americans compared to Whites (51 +/- 7 vs 70 +/- 4 mmol/day, P=.002). We saw no difference in percent body fat, BMI, SBP, or DBP between African Americans and Whites. After separately accounting for K+ excretion and Na+ excretion and BMI, plasma aldosterone levels remained significantly different between the two ethnic groups. After adjusting for percent body fat, PA levels were not significantly different between the two ethnic groups (P = .06).


CONCLUSIONS
The findings of the current study indicate that PA levels differ between African American and White prehypertensives and this difference may partly be due to ethnic variability in K+ excretion and percent body fat.
Jones
Jennifer
J
Department of Kinesiology, University of Maryland, College Park, Maryland, USA. jennifer.jones@utsouthwestern.edu
Park
Jung-Jun
JJ
Dowling
Thomas
T
Phares
Dana
D
Park
Joon-Young
JY
Brown
Michael
M
D050154:Adiposity; D001741:Black or African American; D000368:Aged; D000450:Aldosterone / Q000097:blood*; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000652:urine*; D012964:Sodium / Q000652:urine; D044465:White People
D000450:Aldosterone; D012964:Sodium; D011188:Potassium