1. Department of Occupational and Environmental Health; School of Public Health; China Medical University; Shenyang Liaoning 110001 People's Republic of China
2. Liaoning Provincial Key Laboratory of Endocrine Diseases; China Medical University; Shenyang People's Republic of China
3. Department of Nutrition and Food Hygiene; School of Public Health; China Medical University; Shenyang People's Republic of China
4. Department of Physiology; the University of Tennessee Health Science Center; Memphis Tennessee 38163 USA