1. Department of Surgery, Hypertension and Vascular Research Center, Wake Forest University School of Medicine , Winston-Salem, NC 27101 , USA
2. Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest University School of Medicine , Winston-Salem, NC 27101 , USA
3. Department of Social Sciences and Health Policy, Division of Public Health Sciences, Wake Forest University School of Medicine , Winston-Salem, NC 27101 , USA
4. Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest University School of Medicine , Winston-Salem, NC 27101 , USA
5. Department of Psychiatry and Behavioral Medicine, Wake Forest University School of Medicine , Winston-Salem, NC 27101 , USA
6. Department of Epidemiology, School of Public Health, University of Washington , Seattle, WA 98105 , USA