Significantly Greater Progression of Intima-Media Thickness of the Carotid Artery in Japanese American Men Than in White Men: The ERA JUMP Study.

Background: Although a westernized lifestyle was associated with increased coronary heart disease (CHD), morbidity, and mortality in first- and second-generation Japanese Americans, CHD mortality was reported to be lower in this population than in whites. The risk profile of CHD for third- and fourth-generation Japanese Americans is not known. We compared the progression of carotid intima-media thickness (CIMT) between third- or fourth-generation Japanese Americans and whites.

Methods: Population-based samples of 473 men (Japanese Americans, 227; whites, 246) aged 40-49 years at baseline and free of clinical cardiovascular disease were examined for CIMT at baseline (2004-2007) and follow-up (2007-2013). CIMT was determined centrally at the University of Pittsburgh, Pittsburgh, Pennsylvania. Analysis of covariance was used to compare annualized progression of CIMT between Japanese Americans and whites, adjusting for cardiovascular risk factors and baseline CIMT.

Results: Progression of CIMT was significantly greater in Japanese Americans than in whites both before and after adjusting for covariates: mean, 14.4 μm/y; 95% confidence interval [CI],12.3-16.4 vs 9.8 μm/y; 95% CI, 7.8-11.7; P < 0.05 and 15.1 μm/y; 95% CI, 13.1-17.1 vs 9.1 μm/y; 95% CI, 7.2-11.0; P < 0.05, respectively. Age, total cholesterol/high-density lipoprotein cholesterol, and diabetes in Japanese Americans and age, hypertension, and lipid medication in whites were significantly associated with progression of CIMT.

Conclusions: The significantly greater progression of CIMT in Japanese Americans than in whites might suggest a higher future burden of CHD in Japanese Americans than in whites. The current study identifies Japanese Americans as an important target group for prevention of CHD. Future research assessing carotid plaque in addition to CIMT is warranted.