The effect of shift work on the risk of coronary artery disease is uncertain. In their interesting study, Kang et al1 found an association between shift work and coronary artery atherosclerosis. The authors well assessed the outcome of the study. The study sample was, however, a small selected population. This study, in line with previous reports,2 ,3 found higher prevalence of cardiovascular risk factors in shift workers than in day workers. The unadjusted ORs, however, increased by 90% after controlling for eight confounding factors. OR increased from 1.77 (CI 0.73 to 4.23) to 3.35 …