title: NT-proBNP and potential vascular calcification in Black and Caucasian African men: the SAfrEIC study.
abstract: OBJECTIVE
  The N-terminal prohormone B-type natriuretic peptide (NT-proBNP) is a reliable marker of cardiac strain. In hypertensive heart disease, NT-proBNP levels increase and may lose its protective function. Simultaneously, the vasculature is also subject to hemodynamic stress, resulting in vascular matrix remodeling and stiffening which contribute to further cardiac alterations. Alkaline phosphatase (ALP) is a marker of osteoblast activity and is involved in vascular calcification. We explored the link between NT-proBNP and ALP in Black and Caucasian African men.
  
  
  METHODS
  This study included 128 Black (mean age, 41.1 years) and 118 Caucasian (mean age, 36.4 years) men. Conventional measurements were acquired along with serum NT-proBNP and ALP.
  
  
  RESULTS
  NT-proBNP correlated positively with ALP (r=0.29; p<0.001) in Black Africans, but inversely in Caucasians (r=-0.20; p=0.024). After minimal adjustment (age, body mass index, systolic blood pressure and arterial compliance), the positive significant correlation of NT-proBNP with ALP remained in Black men (r=0.225; p=0.014), whereas significance was lost in Caucasian men. Multiple regression analyses confirmed the independent association of NT-proBNP with ALP in Black men (R2=0.37; beta=0.248; p=0.005), as well as in younger Black men (R2=0.26; beta=0.375; p<0.001; n=96), with no significance in Caucasians.
  
  
  CONCLUSIONS
  NT-proBNP is independently and positively associated with ALP in Black African men. This was however not evident in Caucasian men. These results suggest that African men are susceptible to potential early vascular calcification and may develop increased cardiac afterload prematurely.
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University (Potchefstroom Campus), Private Bag x6001, Potchefstroom 2520, South Africa. ruan.kruger@nwu.ac.za
authors.forename: Ruan
authors.initials: R
authors.lastname: Kruger
authors.forename: Rudolph
authors.initials: R
authors.lastname: Schutte
authors.forename: Hugo W
authors.initials: HW
authors.lastname: Huisman
authors.forename: Michael H
authors.initials: MH
authors.lastname: Olsen
authors.forename: Aletta E
authors.initials: AE
authors.lastname: Schutte
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D044383:Black People; D001808:Blood Vessels / Q000473:pathology; D002114:Calcinosis; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D013019:South Africa; D059289:Vascular Stiffness / Q000502:physiology; D044465:White People
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D000469:Alkaline Phosphatase