Race-ethnic differences in the extent, prevalence, and progression of coronary calcium.
OBJECTIVE
To compare across four race-ethnic groups the baseline prevalence and extent of coronary calcium and the 7-year rate of progression in the extent of coronary calcium.


METHODS
The South Bay Heart Watch is a prospective cohort study designed to appraise the value of coronary calcium for predicting cardiovascular outcomes in asymptomatic adults with cardiac risk factors. Statistical analyses were conducted to evaluate ethnic differences in the prevalence, extent, and progression of coronary calcium among Caucasian, African-American, Hispanic, and Asian participants.


METHODS
Population-based study.


METHODS
Between December 1990 and December 1992, 1289 participants without coronary heart disease underwent baseline risk factor screening and computed tomography for coronary calcification (Cohort 1). Seven years later, 828 (64%) participants returned for follow-up evaluation and re-scanning (Cohort 2).


METHODS
Prevalence, extent, and progression of coronary artery calcium.


RESULTS
In Cohort 2, compared to Whites, African Americans had a lower prevalence of coronary calcium at baseline (P=.012) and follow-up (P=.005), smaller calcium scores at baseline (P=.005) and follow-up (P=.0004), and less progression (P=.001); Hispanics had a lower prevalence of coronary calcium at follow-up (P=.04) with smaller calcium scores (P=.011), and less progression (P=.009). In contrast, no differences were seen between Whites and Asian/Pacific Islanders. Race-ethnic differences in progression persisted after adjusting for risk factors and participation bias (P<.05).


CONCLUSIONS
The present results lend further credence to the notion that race-ethnic differences exist in the prevalence and rate of progression of coronary calcification. The relationship between calcification and the incidence of coronary heart disease in these race-ethnic groups needs further exploration.
Kawakubo
Miwa
M
Statistical Consultation and Research Center, Department of Preventive Medicine, Keck School of Medicine, University of Southern California, USA.
LaBree
Laurie
L
Xiang
Min
M
Doherty
Terence M
TM
Wong
Nathan D
ND
Azen
Stanley
S
Detrano
Robert
R
D000368:Aged; D002113:Calcification, Physiologic; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000503:physiopathology; D002118:Calcium / Q000032:analysis*; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000503:physiopathology; D018450:Disease Progression; D005006:Ethnicity / Q000145:classification; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed
D002118:Calcium