Racial differences in abnormal ambulatory blood pressure monitoring measures: Results from the Coronary Artery Risk Development in Young Adults (CARDIA) study.
BACKGROUND
Several ambulatory blood pressure monitoring (ABPM) measures have been associated with increased cardiovascular disease risk independent of clinic blood pressure (BP). African Americans have higher clinic BP compared with Whites but few data are available on racial differences in ABPM measures.


METHODS
We compared ABPM measures between African American (n = 178) and White (n = 103) participants at the Year 5 Coronary Artery Risk Development in Young Adults study visit. BP was measured during a study visit and the second and third measurements were averaged. ABPM was conducted over the following 24 hours.


RESULTS
Mean ± SD age of participants was 29.8 ± 3.8 years and 30.8 ± 3.5 years for African Americans and Whites, respectively. Mean daytime systolic BP (SBP) was 3.90 (SD 1.18) mm Hg higher among African Americans compared with Whites (P < 0.001) after age-gender adjustment and 1.71 (SD 1.03) mm Hg higher after multivariable adjustment including mean clinic SBP (P = 0.10). After multivariable adjustment including mean clinic SBP, nighttime SBP was 4.83 (SD 1.11) mm Hg higher among African Americans compared with Whites (P < 0.001). After multivariable adjustment, the African Americans were more likely than Whites to have nocturnal hypertension (prevalence ratio: 2.44, 95% CI: 0.99-6.05) and nondipping (prevalence ratio: 2.50, 95% CI: 1.39-4.48). The prevalence of masked hypertension among African Americans and Whites was 4.4% and 2.1%, respectively, (P = 0.49) and white coat hypertension was 3.3% and 3.9%, respectively (P = 0.99). Twenty-four hour BP variability on ABPM was higher among African Americans compared with Whites.


CONCLUSIONS
These data suggest racial differences in several ABPM measures exist.
Department of Epidemiology, University of Alabama at Birmingham, Birmingham, Alabama, USA; pmuntner@uab.edu.
Paul
P
Muntner
Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA;
Cora E
CE
Lewis
Department of Medicine, Columbia University, New York, New York, USA;
Keith M
KM
Diaz
Department of Epidemiology, University of Alabama at Birmingham, Birmingham, Alabama, USA;
April P
AP
Carson
Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA;
Yongin
Y
Kim
Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA;
David
D
Calhoun
Department of Preventive Medicine, Northwestern University, Chicago, Illinois, USA;
Yuichiro
Y
Yano
Department of Family Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.
Anthony J
AJ
Viera
Department of Medicine, Columbia University, New York, New York, USA;
Daichi
D
Shimbo
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods*; D002940:Circadian Rhythm; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000208:ethnology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology*; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D044469:Racial Groups; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
ambulatory blood pressure; blood pressure; disparities; hypertension; race.