1. Department of Epidemiology; Harvard School of Public Health; Boston Massachusetts USA
2. The Channing Laboratory, Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston Massachusetts USA
3. Division of Sleep Medicine, Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston Massachusetts USA
4. Department of Epidemiology and Community Health; Virginia Commonwealth University; Richond Virginia USA
5. Department of Nutrition; Harvard School of Public Health; Boston Massachusetts USA
6. School of Public Health, Peking Union Medical College; Beijing China