1. Department of Epidemiology, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
2. Public Health School, Gansu University of Chinese Medicine, Gansu, China
3. Department of Environmental Health Sciences, Yale University School of Public Health, New Haven, CT, USA
4. Department of Surgery, Yale University School of Medicine, New Haven, CT, USA
5. Department of Epidemiology, Public Health School, Peking University Health Science Center, Beijing, China