Remission of congenital hyperinsulinism following conservative treatment: an exploratory study in patients with KATP channel mutations

During conservative treatment, congenital hyperinsulinism (CHI) can resolve spontaneously. This study describes the hormonal and metabolic profiles in three patients with ABCC8/KCNJ11 mutations in clinical remission.An age-adapted fasting and oral glucose tolerance test (OGTT) were performed.All patients (aged 6-9 years) tolerated age-adapted fasting durations (20, respectively 24 h), without reaching glucose concentrations ≤2.5 mmol/L, nor developing hypoglycemia-related symptoms. Nevertheless, insulin concentrations from all patients exceeded the 90th reference percentile at the end of the fasting test (range: 4.2-15.8 mU/L). During the OGTT, one patient (patient 2; BMI: 23.4 kg/m2; age: 7 years) reached a glucose concentration of 11.4 mmol/L after 2 h (concomitant insulin concentration: 148.3 mU/L).The insulin concentration profiles in CHI patients in apparent clinical remission range from almost complete normalization to persistent, yet attenuated, hypersecretion. The hyperglycemia, detected during the OGTT, must be further monitored.