Cardiovascular disease is of public health significance due to its highest rates of mortality. Atherosclerotic cardiovascular events can often result in fatal or disabling non-fatal events. More than half of CHD fatal events do not show earlier symptoms. Early identification of subclinical atherosclerosis and establishment of preventive control are important to reduce CHD mortality and morbidity. The present study aimed to examine: 1) whether n-6 fatty acids are inversely associated with plasminogen activator inhibitor-1 (PAI-1) and fibrinogen; 2) whether vitamin D deficiency is associated with subclinical atherosclerosis; and 3) whether Japanese men have lower incidence or progression of CAC than Caucasian men, and further if marine n-3 fatty acids are inversely associated with incidence or progression of CAC. To test these aims, the Electron-Beam Tomography, Risk Factor Assessment among Japanese and U.S. Men in Post-World War II Birth Cohort (ERA-JUMP) study was utilized.The findings were: 1) in a population-based cross-sectional-sample of 915 men aged 40-49, serum n-6 fatty acids were inversely and significantly associated with PAI-1 but not with fibrinogen; 2) in 295 middle-aged men of a population-based cross-sectional sample, Japanese men showed lower levels of serum vitamin D, despite their habitual fish intake as a major dietary intake, than Caucasian or Japanese-American men. Further, vitamin D deficiency was not associated with subclinical atherosclerosis as measured by intima-media thickness (IMT) and CAC, except for significant associations on IMT in a univariate model among Caucasian men, and on CAC in both univariate and multivariate models among Japanese-American men; and 3) in the follow-up study of 472 men, Japanese men had a significantly lower incidence and progression of CAC than Caucasian men. Japanese men showed significant risk reduction on incident CAC associated with marine n-3 PUFA. However, Japanese and Caucasian men showed no significant associations of marine n-3 PUFA on the progression of CAC. Future studies to examine the causal associations as well as underlying mechanisms are warranted. From the public health importance, these findings extend our understanding of n-3 and n-6 polyunsaturated fatty acids and vitamin D related to subclinical atherosclerosis as well as help to establish public health guidelines
