ABSTRACT
INTRODUCTION: Transient neonatal diabetes mellitus (TNDM) is a rare condition that is characterized by the presence of diabetes mellitus during the first 6 months of life and remission by 18 months of age. It usually relapses at a median age of 14 years. Hyperinsulinaemic hypoglycaemia is a relatively common complication during remission. Although ß-cell function is reported to be impaired at relapse, the clinical course of glycaemic profiles during remission in patients with TNDM remains largely unknown. CASE PRESENTATION: Longitudinal glycaemic profiles were investigated annually from remission (185 days) to relapse (14.5 years) in a patient with TNDM due to paternal 6q24 duplication using the oral glucose tolerance test (glucose intake: 1.75 g/kg to a maximum of 75 g). The patient's ß-cell function and insulin sensitivity were assessed by calculating the insulinogenic index, homeostasis model assessment of ß-cell function (HOMA-ß), homeostasis model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index, and Matsuda index. Early insulin response to glucose intake was impaired throughout remission, whereas fasting insulin and ß-cell function by HOMA-ß gradually increased in the first few years since remission, followed by a gradual decline in function. In contrast, HOMA-IR fluctuated and peaked at 6.5 years of age. CONCLUSION: This is the first report of annual longitudinal glycaemic profiles in a patient with 6q24-related TNDM during remission. We identified fluctuations in ß-cell function and insulin resistance during remission.
