Long-term follow-up of 114 patients with congenital hyperinsulinism.

BACKGROUND: The term congenital hyperinsulinism (CHI) comprises a group of different genetic disorders with the common finding of recurrent episodes of hyperinsulinemic hypoglycemia.

OBJECTIVE: To evaluate the clinical presentation, diagnostic criteria, treatment and long-term follow-up in a large cohort of CHI patients.

PATIENTS: The data from 114 patients from different hospitals were obtained by a detailed questionnaire. Patients presented neonatally (65%), during infancy (28%) or during childhood (7%).

RESULTS: In 20 of 74 (27%) patients with neonatal onset birth weight was greatly increased (group with standard deviation scores (SDS) >2.0) with a mean SDS of 3.2. Twenty-nine percent of neonatal-onset vs 69% of infancy/childhood-onset patients responded to diazoxide and diet or to a carbohydrate-enriched diet alone. Therefore, we observed a high rate of pancreatic surgery performed in the neonatal-onset group (70%) compared with the infancy/childhood-onset group (28%). Partial (3%), subtotal (37%) or near total (15%) pancreatectomy was performed. After pancreatic surgery there appeared a high risk of persistent hypoglycemia (40%). Immediately post-surgery or with a latency of several Years insulin-dependent diabetes mellitus was observed in operated patients (27%). General outcome was poor with a high degree of psychomotor or mental retardation (44%) or epilepsy (25%). An unfavorable outcome correlated with infancy-onset manifestation (chi(2)=6.1, P=0.01).

CONCLUSIONS: The high degree of developmental delay, in particular in infancy-onset patients emphasizes the need for a change in treatment strategies to improve the unfavorable outcome. Evaluation of treatment alternatives should take the high risk of developing diabetes mellitus into account.