1. Department of Internal Medicine (A.K., J.A.d.L., B.D.L.), at the University of Texas Southwestern Medical Center, Dallas, TX.
2. Division of Cardiology (A.K., J.A.d.L., B.D.L.), at the University of Texas Southwestern Medical Center, Dallas, TX.
3. Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, CA (M.J.B.).
4. The National Heart, Lung, and Blood Institute’s the Framingham Heart Study, Framingham, Massachusetts; Cardiology Section, Department of Medicine, Boston Veteran’s Administration Healthcare (C.J.O.).
5. Department of Clinical Sciences (C.A.A.) at the University of Texas Southwestern Medical Center, Dallas, TX.
6. National Aeronautics and Space Agency, Johnson Space Center, Houston, TX (J.L.).
7. Department of Mathematics, Boston University, MA (J.M.M.).
8. Department of Biostatistics, University of Washington, Seattle (R.L.M.).
9. Divison of Cardiology, Georgetown University; and MedStar Georgetown University Hospital and MedStar Health Research Institute, Washington, DC (A.T.).
10. Institute for Exercise and Environmental Medicine, Presbyterian Hospital, Dallas, TX (B.D.L.).