1. Department of Medicine; University of Vermont; Burlington VT USA
2. Division of Epidemiology and Community Health; School of Public Health; University of Minnesota; Minneapolis MN USA
3. Department of Internal Medicine/Cardiology; Wake Forest University School of Medicine; Winston-Salem NC USA
4. National Institutes of Health Clinical Center; Bethesda MD USA
5. Department of Pathology; University of Vermont; Burlington VT USA
6. Division of Public Health Sciences; Wake Forest University School of Medicine; Winston-Salem NC USA