1. Department of Endocrinology, Daqing Oil Field General Hospital, Daqing, Heilongjiang 163411, P.R. China
2. Dental Department, Daqing Oil Field General Hospital, Daqing, Heilongjiang 163411, P.R. China
3. Department of Endocrinology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China