Progression of coronary artery calcium in Japanese American men and white men in the ERA JUMP study.

Background: Progression of coronary artery calcium (CAC) is associated with increased risk of coronary heart disease (CHD) and is reported to be greater in whites than blacks, Hispanics, and Chinese in the US. Our objective was to compare progression of CAC between Japanese Americans and whites.

Methods: Population-based sample of 303 Japanese American men and 310 white men aged 40-49years, free of clinical cardiovascular disease at baseline, were examined for CAC at baseline (2004-2007) and follow-up (2008-2013). Progression of CAC was defined as change in coronary calcium scores (CCS) in participants with baseline CCS>0 and incident CAC in participants with baseline CCS=0. Multiple linear regression and relative risk regression were used to compare change in CCS scores and incident CAC between the two races, respectively.

Results: Japanese American men had significantly greater annual change in CCS than white men (median [interquartile range]: 11.3 Agatston units [1.4, 24.9] vs 2.5 [-0.22, 14.5]) in the unadjusted analyses. After adjusting for cardiovascular risk factors and follow-up time, change in CCS (beta±CI) and incidence rate ratio of CAC was similar in Japanese American men and white men: -0.12 (-0.34, 0.15) and (0.87 [95% CI: 0.20, 3.9]), respectively.

Conclusions: In contrast to previously reported greater progression of CAC in whites than other races, we found a similar progression of CAC in Japanese American men as white men. Our study identifies Japanese American men as a target group for prevention of CHD. Large prospective studies are warranted to confirm these findings.