Coronary artery calcification in Japanese men in Japan and Hawaii

Area of Science:

• Cardiovascular Epidemiology
• Atherosclerosis Research
• Preventive Cardiology

Background:

• The prevalence of atherosclerosis differs significantly between Japan and the United States.
• Genetic variations often confound comparisons of atherosclerosis prevalence.
• Coronary artery calcification (CAC) serves as a key marker for subclinical atherosclerosis.

Purpose of the Study:

• To compare subclinical atherosclerosis, indicated by CAC, between Japanese men residing in Japan and Japanese men residing in Hawaii.
• To investigate the influence of risk factors on CAC prevalence in these distinct populations.
• To identify potential protective factors against atherosclerosis in Japanese men in Japan.

Main Methods:

• Cross-sectional study comparing CAC scores and cardiovascular risk factors.
• Participants included 311 men in Japan and 300 men in Hawaii, aged 40-50 years, without cardiovascular disease.
• Data collected between 2001 and 2005.

Main Results:

• After age adjustment, men in Hawaii had a threefold excess odds of prevalent CAC scores of >= 10 compared to men in Japan (relative odds = 3.2).
• Men in Hawaii exhibited a generally poorer risk factor profile, yet men in Japan had a higher smoking prevalence (49.5% vs. 12.7%).
• Even after risk factor adjustment, the relative odds of CAC scores of >= 10 remained significantly higher in Hawaii versus Japan (relative odds = 4.0).

Conclusions:

• A significant excess of coronary artery calcification was observed in Japanese men in Hawaii compared to those in Japan.
• Identified cardiovascular risk factors did not fully explain the lower CAC prevalence in Japan.
• Further research is warranted to elucidate the protective factors contributing to lower atherosclerosis burden in Japanese men in Japan.