Clinical Predictors of Transient versus Persistent Neonatal Hyperinsulinism

Hyperinsulinism (HI), the most common neonatal cause of persistent hypoglycemia, can be associated with prolonged hospitalizations and risk for long-term neurological sequelae. Rapid identification of transient versus persistent forms of HI is crucial to optimize management.

The aims of the study were to assess the ability of clinical and biochemical features at presentation to predict transient versus persistent HI, and to evaluate differences in hospital outcomes.

This study is a retrospective review of 79 infants with HI admitted to the Hospital for Sick Children, Toronto, from 2012 to 2017. Patients were classified into 3 groups: transient and the 2 persistent forms, diazoxide responsive and diazoxide unresponsive (DU).

Infants with birth weight >90th percentile had an 8-fold increased risk of having a persistent form of HI (OR 8.8, 95% CI 2.5-30) and a 21-fold increased risk of having a DU form of HI (OR 21.1, 95% CI 4.9-91.8). The majority of children with transient HI and a birth weight >90th percentile were born to mothers with gestational diabetes. There were no other useful clinical or biochemical presenting features that differentiated the groups. There were significant differences in outcome measures, with the DU children more likely to require gastrostomy tube insertion and have an extended length of hospital admission.

A higher birth weight in the absence of maternal gestational diabetes is highly associated with a persistent form of HI. Given the marked difference in clinical outcomes between groups, expedited genetic testing should be considered in infants with this presentation to inform clinical management.