The results of the present study show that shift work may have an effect on type 2 diabetic patients’ health such as blood sugar control, hypoglycemic symptoms, and mental health problems. The difference was found in the control of diabetes between the two worker groups. This may be caused by shift workers having less sleep time than day workers so circadian rhythm of shift workers was interfered. Disruption of circadian rhythm may influence cortisol secretion(11) and dose-response patterns of oral hypoglycemic agents(5).