1. From the Division of Nephrology, VAMC San Francisco and University of California (A.M.O.), San Francisco, Calif; Department of Epidemiology and Biostatistics (D.V.G.), University of California, San Francisco, Calif; Framingham Heart Study (C.S.F.), National Heart, Lung, and Blood Institute, Framingham, Mass; and Division of Nephrology, University of California (C.H.), San Francisco, Calif.