Maturity onset diabetes of the youth (MODY) is frequently associated with obesity and often requires high daily amounts of insulin therapy. Weight loss has a beneficial effect on pancreatic endocrine function in these patients. However, the problems of insulin regulation and carbohydrate tolerance frequently complicate dieting.

A protein-sparing modified fast (PSMF) allows effective control of carbohydrate metabolism and hunger, by reducing serum glucose and insulin and increasing free fatty acid and ketone concentrations.

In a preliminary investigation, we treated two obese insulin dependent MODY patients who were admitted in diabetic ketoacidosis. Patient 1 is an 11 year old black female with a weight of 66.8 kgs (142% ideal body weight (IBW)); patient 2 is a 15 year old black male weighing 98.8 kgs (152% IBW). Prior to this admission these patients' maintenace insulin dosages were 60 IU/day and 70 IU/day, respectively. Both patients were started on a PSMF diet and were taken off insulin immediately upon commencing the diet. Blood glucose levels stayed within safe limits and none required supplemetal exogenous insulin. Both patients could be discharged without insulin while continuing with the PSMF.

To our knowledge, this is the first report to investigate the effects of combined PSMF and withdrawal of exogenous insulin in children. These preliminary data suggest that PSMF is a safe and effective treatment for obese children with insulin dependent MODY-type diabetes mellitus.