Evidence that elevated serum triglyceride levels are associated with increased risk for atherosclerotic events is increasing. In this issue of JAMA, 2 large, long-term prospective cohort studies conducted in different populations by Bansal and colleagues1 and by Nordestgaard and colleagues2 support the role of nonfasting triglyceride levels as a significant risk factor for coronary heart disease (CHD) events. However, a high serum triglyceride level is associated with abnormal lipoprotein metabolism, as well as with other CHD risk factors including obesity, insulin resistance, diabetes mellitus, and lowered levels of high-density lipoprotein cholesterol (HDL-C).3 When determining CHD risk, how important is it to know which came first—high serum triglyceride levels or the risk factors that cause high levels?