1. Department of Family and Community Medicine, Chung Shan Medical University Hospital , Taichung 402306, Taiwan
2. Department of Occupational Medicine, Chung Shan Medical University Hospital , Taichung 402306, Taiwan
3. School of Medicine, Chung Shan Medical University , Taichung 402306, Taiwan
4. Institute of Medicine, Chung Shan Medical University , Taichung 402306, Taiwan
5. Division of Cardiology, Department of Internal Medicine, Chung Shan Medical University Hospital , Taichung 402306, Taiwan