Plasma C-terminal pro-endothelin-1 is associated with target-organ damage in African Americans with hypertension.
BACKGROUND
Endothelin-1 (ET-1) is a vasoactive peptide with vasoconstrictor and mitogenic properties. We investigated whether plasma levels of C-terminal pro-ET-1 (CT-proET-1), a newly described stable fragment of the ET-1 precursor, are associated with target-organ damage in hypertension.


METHODS
Participants included 981 African Americans (65 ± 9 years, 71% women) and 812 non-Hispanic whites (61 ± 9 years, 54% women) ascertained from sibships with hypertension. We measured plasma CT-proET-1 by an immunoluminometric assay. Measures of target-organ damage included the ankle-brachial index (ABI) and urinary albumin:creatinine ratio (UACR). Multivariable regressions analyses were employed to assess whether plasma CT-proET-1 levels were independently associated with ABI and UACR.


RESULTS
In hypertensive African Americans, higher plasma levels of CT-proET-1 were significantly associated with lower ABI (P < 0.01) and higher UACR (P < 0.01). After adjustment for age, sex, body mass index, systolic blood pressure (SBP) and diastolic blood pressure (BP), diabetes, serum glucose, insulin use, estimated glomerular filtration rate (eGFR), history of smoking, total and high-density lipoprotein cholesterol, medication use, and previous history of myocardial infarction (MI) or stroke, higher plasma levels of CT-proET-1 remained significantly associated with lower ABI (P < 0.01) and higher UACR (P = 0.02). In non-Hispanic white hypertensives, higher plasma levels of CT-proET-1 were weakly associated with higher UACR (P = 0.02) and with lower ABI (P = 0.07). After adjustment for the relevant covariates, no statistically significant associations between CT-proET-1 and ABI or UACR were present in whites.


CONCLUSIONS
Plasma levels of CT-proET-1 were independently associated with lower ABI and greater UACR in African American but not non-Hispanic white adults with hypertension.
Habib
Ammar
A
Mayo Clinic, Rochester, Minnesota, USA.
Al-Omari
Malik A
MA
Khaleghi
Mahyar
M
Morgenthaler
Nils G
NG
Struck
Joachim
J
Bergmann
Andreas
A
Mosley
Thomas H
TH
Turner
Stephen T
ST
Kullo
Iftikhar J
IJ
D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D000419:Albuminuria / Q000208:ethnology* / Q000378:metabolism*; D055109:Ankle Brachial Index; D003404:Creatinine / Q000652:urine; D019332:Endothelin-1 / Q000097:blood* / Q000737:chemistry; D005260:Female; D006801:Humans; D006977:Hypertension, Renal / Q000208:ethnology* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017434:Protein Structure, Tertiary; D012044:Regression Analysis; D012307:Risk Factors; D044465:White People / Q000706:statistics & numerical data
D019332:Endothelin-1; D003404:Creatinine