Prolonged Fasting in Type 1 Diabetes mellitus – case study from a patient‘s perspective Bettina Berger1, Rainer Stange2, Andreas Michalsen2, David Martin 1,3 1University Witten/Herdecke, Health, Herdecke, Germany, Institut of Integrative Medizin; 2 Immanuel Hospital , Berlin, Germany 3 Filderklinik und Kinderklinik der Universität Tübingen Kontakt: bettina.berger@uni-wh.de Background Fasting as a medical treatment has been proven to be a valuable therapeutic method for chronic diseases like rheumatoid arthritis, hypertension, and metabolic syndrome (1). For patients with Type 1 Diabetes mellitus (T1DM), fasting therapy has neither been recommended nor excluded by fasting guidelines (2) and most fasting clinics do not accept people with T1DM for fear of ketoacidosis. The literature on fasting in T1DM is scarce and limited to fasting during Ramadan (3). Aim Report on a single case study of prolonged patient-initiated fasting in a T1DM patient for about seven days in relation to safety and feasability. Methods A female patient (age 49 y) suffering from T1DM for 39 years, decided to fast on her own to reduce diabetes related fatigue (4). Fasting was scheduled for 7 days. Insulin dosage was reduced from around 36 units short-acting insulin (Actrapid) and 18 units basal insulin (Levemir)/d to basal insulin only (18 units/d). The person consumed water, tea, and vegetable broth only. She measured blood sugar level 10-12 times/d (sensor free style libre) and took carbohydrates in case of blood sugar level dropping below 60 mg/dl. She measured urine ketone levels (urine sticks) daily and took carbohydrates in case of uncertainty. The other blood values were analysed during regular doctor visits. All other values were recorded in a diary. Fatigue was observed daily and recorded in a diary. Results Fasting was performed during 7 days without any carbohydrate intake. Mild hypoglycemia (treated with two units of carbohydrates) and mild hyperglycemia (treated with four units of short acting insulin) occurred twice each, and there was no serious hypoglycemia or hyperglycemia, nor ketoacidosis. Glucose profile was balanced between 60 and 240 mg/dl, av. 150 mg/dl during the whole time. During long-time follow-up, the subject improved in relation to weight (from 78 kg to 75kg), HBA1C (7.8 mg/dl to 6.9 mg/dl), LDL (164 to 154 mg/dl) and subjective fatigue. . Date 2016 (dd/mm) Levemir IU Actrapid IU Carbo-hydrates and time Ketone (urine sticks) Physical activity 08/10 16 17 - 1 h walking 09/10 18 4 + 30‘ walking 10/10 ++ 60‘ bicycling 11/10 12/10 13/10 +++ 60‘ walking 14/10 20 g (8:00) 15/10 20 g (9:00) 5 h gardening 16/10 12 40 g 3h paddling 17/10 24 120 g Laboratory Parameter 20.09. 2016 16.12. Cholesterol (mg/dl) 228 237 HDL (mg/dl) 69 80 LDL (mg/dl) 162 154 HBA1C (%) 7,8 6,9 Weight (kg) 78 75 Urin acid (mmol/l) 3,1 2,2 Creatinine (mg/dl) 0,76 Symbol of independend Self-help-group „Insuliner“ in Germany, empowering patients with T1DM Discussion and conclusion To the best of our knowledge, this is the first case report on prolonged complete fasting in T1DM. It indicates that people with Type 1 diabetes can safely participate in prolonged fasting provided they reduce their usual insulin dose and carefully supervise their blood sugar level. Interventional studies are needed on the effects of fasting on metabolism, quality of life, chronic fatigue and longevity. Using the CARE guidelines, patients can report single case experiences on their own, which might be relevant for developing interventional study designs in order to gain new evidence on the effectiveness of fasting therapy. Literature 1 Michalsen A, Li C. Fasting therapy for treating and preventing disease - current state of evidence. Forsch Komplementmed. 2013;20(6):444-53. 2 Wilhelmi de Toledo F, Buchinger A, Burggrabe H, Holz G, Kuhn C, Lischka E, et al. Fasting therapy - an expert panel update of the 2002 consensus guidelines. Forsch Komplementmed. 2013;20(6):434-43. 3 Alabbood MH, Ho KW, Simons MR. The effect of Ramadan fasting on glycaemic control in insulin dependent diabetic patients: A literature review. Diabetes & metabolic syndrome. 2016. 4 Goedendorp MM, Tack CJ, Steggink E, Bloot L, Bazelmans E, Knoop H. Chronic fatigue in type 1 diabetes: highly prevalent but not explained by hyperglycaemia or glucose variability. Diabetes Care. 2013 Aug 15.