1. From the Framingham Heart Study, National Heart, Lung, and Blood Institute (J.W.M., E.J.B.) and Section of Cardiovascular Medicine, Department of Medicine, Boston University, MA (J.W.M., E.J.B.); Section of Preventive Medicine and Epidemiology, Boston University School of Medicine, MA (E.J.B.); and Epidemiology Department, Boston University School of Public Health (E.J.B.), Boston, MA.