Distinctive characteristics of diabetes mellitus after hematopoietic cell transplantation during childhood

We report on six patients who developed diabetes mellitus after hematopoietic cell transplantation (HCT). The prevalence in our cohort of long-term survivors after HCT performed below 18 yr of age was 3%. The median age at onset of diabetes was 22.4 yr (range 11.3-34.4). The median period between HCT and diabetes was 10.1 yr (range 5.6-22.1). Five out of the six patients received total irradiation therapy and five had other endocrinological abnormalities. The onset of diabetes in all patients was insidious and none had diabetic ketoacidosis. Body mass indexes at diabetes onset were within normal levels. The clinical and laboratory features that characterized our patients with diabetes after HCT make it difficult to classify them as having type-1 or type-2 diabetes. The relatively high prevalence of diabetes and its insidious onset in this group of patients, advocate clinicians to evaluate carefully even slight variations in fasting blood glucose, usually included in the routine biochemistry follow-up. These data also suggest that HbA1c and oral glucose-tolerance test should be added to the follow-up program of late complications if fasting blood glucose levels are slightly increased.