Reference values for SphygmoCor measurements in South Africans of African ancestry.
BACKGROUND
Measurements of blood pressure (BP) together with applanation tonometry at the radial and femoral arteries allow for reproducible assessments of various indexes of arterial stiffness, including peripheral (PP(p)) and central (PP(c)) pulse pressures, peripheral (AI(p)) and central (AI(c)) augmentation indexes, and aortic pulse wave velocity (PWV). In the absence of an outcome-driven and ethnicity-specific reference frame, we defined preliminary diagnostic thresholds for subjects of African descent living in Africa, using the distributional characteristics of these hemodynamic measurements.


METHODS
We randomly recruited 347 subjects from a South African population of African origins. The PP(p) was the average difference between systolic and diastolic BP measured five times consecutively at one home visit. For measurement of PP(c), AI(p), AI(c), and PWV, we used a high-fidelity micromanometer interfaced with a laptop computer running the SphygmoCor software. For analyses we selected 185 subjects without hypertension, diabetes, and previous or concomitant cardiovascular disease.


RESULTS
Mean age (33.5 years) was similar in 77 men and 108 women. The PP(p), PP(c), AI(p), AI(c), and PWV significantly increased with age. The 95th prediction bands of this relation at age 30 years, approximated to 70 mm Hg for PP(p), 50 mm Hg for PP(c), 100% for AI(p), 40% for AI(c), and 8.0 m/sec for PWV. The aforementioned thresholds would need adjustment by approximately 2.5 mm Hg, 4.0 mm Hg, 10%, 6%, and 1.0 m/sec, respectively, for each decade that age differs from 30 years.


CONCLUSIONS
Pending validation in prospective outcome-based studies 70 mm Hg for PP(p), 50 mm Hg for PP(c), 100% for AI(p), 40% for AI(c), and 8.0 m/sec might be considered as preliminary thresholds to diagnose increased arterial stiffness in young adult subjects of African descent.
Shiburi
Cleopatra P
CP
Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Staessen
Jan A
JA
Maseko
Muzi
M
Wojciechowska
Wiktoria
W
Thijs
Lutgarde
L
Van Bortel
Luc M
LM
Woodiwiss
Angela J
AJ
Norton
Gavin R
GR
D000293:Adolescent; D000328:Adult; D044383:Black People / Q000235:genetics; D001794:Blood Pressure / Q000235:genetics / Q000502:physiology; D003971:Diastole / Q000502:physiology; D005260:Female; D005263:Femoral Artery / Q000502:physiology / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000208:ethnology* / Q000235:genetics / Q000503:physiopathology; D008297:Male; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D017534:Radial Artery / Q000502:physiology; D012016:Reference Values; D015203:Reproducibility of Results; D012984:Software; D013019:South Africa; D019722:Sphygmomanometers; D013599:Systole / Q000502:physiology