Type 1 diabetes and prolonged fasting

Aims: Fasting is common in several religions. The aims of this study were to determine if prolonged fasting (> 25 h) is safe for individuals with Type 1 diabetes and to identify factors associated with success. Methods: Patients intending to fast were instructed on insulin dose adjustments, frequent glucose monitoring and when to terminate the fast using a standard protocol. Clinical and epidemiological factors were recorded and a comparison was made between successful and unsuccessful fasters. Results: Of 56 subjects who intended to fast, 37 (65%) were successful. Individuals terminated their fast in the presence of either hypoglycaemia or hyperglycaemia and adherence to the protocol was high. There were no serious side-effects of fasting. Successful fasters had greater reductions in insulin dosage and higher HbA_1c. There were no differences between individuals taking intermittent insulin injections and those with continuous infusion pumps. Conclusions: Persons with Type 1 diabetes can participate safely in prolonged fasts provided they reduce their usual insulin dose significantly and adhere to guidelines regarding glucose monitoring and indications for terminating fasting.