1. National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts;
2. Harvard Medical School, Boston, Massachusetts;
3. Department of Mathematics, Boston University and School of Public Health, Division of Biostatistics, Boston, Massachusetts;
4. Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
5. Department of Cardiology and Preventive Medicine, Boston University, Boston, Massachusetts;
6. Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
7. Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.