Effect of Ramadan fasting on glycemic control in patients with Type 2 diabetes

Background: Although Muslim patients with Type 2 diabetes may be exempt from fasting during Ramadan for medical reasons, a high proportion of them fast. Aim: To investigate the association between Ramadan fasting and glycemic control in patients with Type 2 diabetes. Subjects and methods: A prospective cohort clinical trial was designed. Eighty-eight patients with Type 2 diabetes (45 male, 43 female, age 51±10 yr) who opted to fast for at least 10 days during the month of Ramadan were recruited. Fasting blood samples were taken at the beginning and end of Ramadan, and 1 month after Ramadan, to assess fasting blood glucose (FBG), fasting insulin, full blood count, glycated hemoglobin (HbA_1c) and fasting lipid profile. Insulin resistance was estimated using the homeostatic model assessment. Anthropometrics and blood pressure were also measured. Results: There was a significant deterioration in FBG and HbA_1c (p=0.002 and p≤0.001, respectively) and significant improvements in HDL and LDL cholesterol and body mass index after Ramadan (p<0.001). Interestingly, HbA_1c showed a reduction 1 month after Ramadan (9.4±2% at the end of Ramadan vs 8.4±2.5% 1 month after Ramadan; p<0.001). Conclusion: Results from this study showed that fasting during Ramadan deteriorated the glycemic control in Type 2 diabetes patients. This was more evident in patients using oral hypoglycemic medication than diet-controlled patients. However, Ramadan fasting had small positive effects on lipid profile and body weight.