| Glucose infusion rate >8 mg/kg/minute |
| Laboratory blood glucose <3 mmol/l with: |
| Detectable serum insulin/C-peptide |
| Suppressed/low serum ketone bodies |
| Suppressed/low serum fatty acids |
| Suppressed branch chain amino acids |
| Serum ammonia level may be raised (HI/HA syndrome) |
| Raised plasma hydroxybutyrylcarnitine and urinary 3-hydroxyglutarate (HADH deficiency) |
| Supportive evidence (when diagnosis is in doubt): |
| Positive glycaemic (>1.5 mmol/l) response to intramuscular/intravenous glucagon |
| Positive glycaemic response to a subcutaneous/intravenous dose of octreotide |
| Low levels of serum IGFBP-1 |
HADH, hydroxyacyl-coenzyme A dehydrogenase; HI/HA, hyperinsulinism and hyperammonaemia; IGFBP-1, insulin growth factor binding protein 1.