Alkaline phosphatase and arterial structure and function in hypertensive African men: the SABPA study.
BACKGROUND
Vascular calcification is believed to be due to the conversion of vascular smooth muscle cells into osteoblast-like cells and is associated with mortality. Since hypertension and related mortality in Africans is a concern, we investigated associations between a marker of osteoblastic activity, alkaline phosphatase (ALP), and measures of arterial structure and function in hypertensive African men.


METHODS
This study included 79 participants. We conducted 24h ambulatory blood pressure and carotid intima-media thickness (cIMT) measurements. cIMT was obtained with an intra-observer variability of 0.04 mm and the cross-sectional wall area (CSWA) was calculated. ALP was measured in serum.


RESULTS
ALP was within its reference range (101.6 vs. 30.0-120.0 U/L), however cIMT was higher when this group was stratified and compared to gender and age-specific reference values. In univariate and partial regressions, and confirmed with multiple regression analyses, 24h systolic blood pressure (β=0.289, p=0.018), 24h pulse pressure (β=0.387, p=0.002), but not 24h diastolic blood pressure (β=0.073, p=0.58), were positively associated with ALP. In addition, mean cIMT (β=0.322, p=0.006) and CSWA (β=0.285, p=0.013) also correlated positively with ALP after adjusting for significant covariates, and after excluding participants with diabetes, renal dysfunction or a HIV positive status.


CONCLUSIONS
Serum alkaline phosphatase is adversely associated with measures of arterial structure and function in hypertensive African men.
Hypertension in Africa Research Team, School for Physiology, Nutrition, Consumer Sciences, North-West University, Potchefstroom Campus, Potchefstroom, South Africa. rudolph.schutte@nwu.ac.za
R
R
Schutte
H W
HW
Huisman
L
L
Malan
J M
JM
van Rooyen
W
W
Smith
M C P
MC
Glyn
C M C
CM
Mels
C M T
CM
Fourie
N T
NT
Malan
A E
AE
Schutte
D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D044383:Black People / Q000208:ethnology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods; D059168:Carotid Intima-Media Thickness; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology*; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000378:metabolism / Q000473:pathology; D013019:South Africa / Q000208:ethnology
D015415:Biomarkers; D000469:Alkaline Phosphatase