Aldosterone and left ventricular hypertrophy in Afro-Caribbean subjects with low renin hypertension.
BACKGROUND
Activity of the renin-angiotensin-aldosterone system is thought to play a major role in determining blood pressure (BP) and target organ damage such as left ventricular hypertrophy. In Afro-Caribbean subjects, however, hypertension tends to be more severe despite lower plasma renin activity. We investigated whether this might be due to a different relation between aldosterone and renin in Afro-Caribbean compared to white subjects.


METHODS
Plasma aldosterone and renin activity were assessed in the morning after 15 min seated in 383 hypertensive subjects of Afro-Caribbean or white ethnicity (61% Afro-Caribbean, 83% on treatment) attending a hypertension clinic in London, UK. Left ventricular mass index (LVMI) was assessed by echocardiography in 276 subjects.


RESULTS
Plasma renin activity was lower in Afro-Caribbean compared to white subjects (0.4 [0.3-1.0] v 1.4 [0.5-3.4] ng/mL/h, medians [interquartile range], P < .0001). Despite this, aldosterone was higher in Afro-Caribbean compared to white subjects (8.0 [6.1-12.6] v 7.4 [2.3-17.1] ng/dL, medians [interquartile range], P < .01). The LVMI corrected for sex and BP was higher in Afro-Caribbean than in white subjects. In Afro-Caribbean but not in white subjects LVMI was independently correlated with plasma aldosterone (standardized regression coefficient, beta= 0.25, P < .001).


CONCLUSIONS
In Afro-Caribbean hypertensive subjects in London, plasma aldosterone is elevated despite lower renin and may contribute to increased severity of hypertension and left ventricular hypertrophy in Afro-Caribbean compared to white subjects.
Stewart
Andrew D
AD
Cardiovascular Division, King's College, London, UK.
Millasseau
Sandrine C
SC
Dawes
Mathew
M
Kyd
Patricia A
PA
Chambers
John B
JB
Ritter
James M
JM
Chowienczyk
Philip J
PJ
D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000097:blood* / Q000502:physiology; D044383:Black People; D001794:Blood Pressure; D017691:Caribbean Region / Q000208:ethnology; D004452:Echocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications / Q000208:ethnology* / Q000503:physiopathology; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000208:ethnology* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012083:Renin / Q000097:blood* / Q000502:physiology; D012084:Renin-Angiotensin System / Q000502:physiology; D044465:White People
D000450:Aldosterone; D012083:Renin