Introduction : Sleep is an indispensable part of one’s lifestyle. On the other hand, sleep disorders may lead to many health problems. Changes in sleep duration are associated with cardiovascular diseases, metabolic disorders, weight gain and obesity. The present study aimed to evaluate the relationship between sleep duration and changes in serum glucose level in type II diabetic patients.

  Methodology : This cross-sectional study was conducted on 108 patients with type II diabetes. A researcher-made questionnaire was used for data collection . T-test , Chi-square and one-way analysis of variance (ANOVA) were performed for data analysis .

  Results : The obtained results showed a significant correlation between fasting blood glucose and sleep duration (P=0.0001, r=0.33). According to the results, the mean sleep duration was 6.2±1.8 hours. Body mass index was significantly higher in diabetic women than diabetic men (P=0.007). Also, serum glucose level in diabetic patients, who slept more than 8 hours, was higher than that reported in other diabetic patients (P=0.01).

  Conclusion : In this study, diabetic patients with longer sleep duration had high fasting blood glucose level. Therefore, prevention of sleep disturbances, with an emphasis on sleep health and normal sleeping time, seems necessary for inhibiting serum glucose variations.