1. From the Departments of Pathology (N.S.J., R.P.T.) and Biochemistry (R.P.T.), University of Vermont, Burlington; the Department of Biostatistics (A.M.A.) and the Departments of Medicine, Epidemiology, and Health Services, Cardiovascular Health Research Unit (B.M.P.), University of Washington, Seattle; the Department of Epidemiology (L.H.K.), University of Pittsburgh School of Public Health, Pittsburgh, Pa; and the Center for Health Studies (B.M.P.), Group Health, Seattle, Wash.