1. From the University of Michigan, Departments of Internal Medicine, Division of Metabolism, Endocrinology, Diabetes (R.P.-B., C.L.M., W.H.H.), and Neurology (J.W.A., E.L.F.), Ann Arbor; Mayo Clinic, Department of Neurology, Rochester, Minn (P.A.L., C.S.); and The Biostatistics Center, George Washington University, Rockville, Md (B.H.W., P.A.C., J.M.L.).