Background: Night shift work negatively affect human health by disturbing circadian rhythm & altering biological functions, due to poor sleep quality. These disturbances have been linked to insulin resistance & poor glycemic control in type 2 diabetic patients (T2DM).

Objectives: to investigate the association between rotating night-shift work and glycemic control among type 2 diabetic nursing staff

Materials and Methods: case-control study included 104 T2DM nursing staff (65 of them on rotating night shift work & the other 39 on fixed day work) in addition to 104 healthy control subjects at Menoufia University hospitals, Egypt. They were subjected to a pre-designed self-administered questionnaire & blood samples for assessment of glycemic control were withdrawn as fasting, two-hour post prandial blood glucose and glycated hemoglobin.

Results: overnight work (62.5%) had significantly worse glycemic control assessed by glucose parameters (FBG, 2Hppg and HbA1c) than those performing day work (37.5%). There was significant association between unhealthy diet, physical inactivity, obesity and night-shift working and DM (p<0.05). Multiple regression analysis revealed factors like positive family history, unhealthy diet, obesity and night-shift working were significant predictors for poor diabetic control.

Conclusion: This study revealed that T2DM nurses working rotating night shifts had poor glycemic control due to chronic circadian misalignment and several factors associated with night shift working as bad dietary foods habits, weight gain, less exercise, night light exposure and endocrinal disturbances. Occupational diabetic health practitioners should be aware of modifying mealtimes, adjusting insulin dosing schedule avoiding factors triggering hypoglycemia episodes by consulting diabetic specialists.