1. Department of Physical Examination, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
2. Department of Internal Medicine, Chenghai People's Hospital, Shantou, China
3. Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
4. Department of Physical Examination, Chenghai People's Hospital, Shantou, China.
5. Department of Public Health and Preventive Medicine, Shantou University Medical College, Shantou, China