Transient increase in glucose variability during Ramadan fasting in patients with insulin-treated type 2 diabetes: A preliminary study.

Aim: We aimed to examine the effect of Ramadan fasting on interstitial glucose control and variability before, during, and after Ramadan in type 2 diabetes patients receiving insulin therapy.

Methods: Participants received a flash glucose monitoring (FGM) system one week before Ramadan that was removed on the sixth or seventh day (pre- and early Ramadan periods) of Ramadan and a second FGM system one week before the end of Ramadan that was removed one week after the end of Ramadan (late and post-Ramadan periods). Fasting blood samples were collected during the pre-, early, and late Ramadan study visits and tested for HbA1c, serum creatinine, and plasma glucose levels.

Results: Thirty-four patients were prospectively included. The standard deviation and coefficient of variation of glucose concentrations were higher in the early Ramadan period than in the pre-Ramadan period, but did not differ in the late or post-Ramadan periods. Changes in the early Ramadan period were restricted to males and patients aged <55 years. No significant changes were observed in the average glucose level, glucose management indicator, time in range, time in hyperglycemia, or time in hypoglycemia at any time point.

Conclusions: Ramadan fasting in patients with insulin-treated type 2 diabetes is associated with an initial increase in glucose variability that quickly returned to pre-Ramadan levels. Ramadan fasting was not associated with any significant changes in glycemic control measures.