1. From the Divisions of Preventive Medicine (P.M.R., C.H.H.), Cardiovascular Diseases (P.M.R.), Infectious Diseases (F.W.), and the Channing Laboratory (M.J.S.), Department of Medicine, Brigham and Women’s Hospital; the Department of Ambulatory Care and Prevention (C.H.H.), Harvard Medical School; and the Departments of Epidemiology (C.H.H., M.J.S.) and Nutrition (M.J.S.), Harvard School of Public Health, Boston, Mass.