1. From the Framingham Heart Study of the National Heart, Lung, and Blood Institute, Framingham, Mass (S.R.P., S.-J.H., D.L., C.S.F.); National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md (S.R.P., S.-J.H., S.C., P.J.S., D.L., C.S.F.); Department of Mathematics, Boston University, Boston, Mass (M.J.P., R.B.D.); and Division of Endocrinology and Metabolism, Brigham and Women’s Hospital and Harvard Medical School, Boston, Mass (C.S.F.).