1. From the Division of Cardiovascular Medicine (H.M.J., J.H.S.), University of Wisconsin Medical School, Madison; the Division of Cardiovascular Medicine (P.S.D.), Duke University Medical Center, Durham, NC; the Tulane Center for Cardiovascular Health and the Department of Epidemiology (S.R.S., S.L., W.C., G.S.B.), Tulane University Health Sciences Center, New Orleans, La; and the Division of Vascular Ultrasound Research (M.G.B., R.T.), Wake Forest University School of Medicine, Winston-Salem, NC.