INS and Hypoglycemia: One study found that 61% of 76 children who underwent a fasting study had a peak cortisol of < 18 μg/dL (497 nmol/L), which is the standard based on the threshold response to insulin-induced hypoglycemia, and subnormal responses were found in congenital hyperinsulinism, KH, and children who tolerated an age-appropriate duration of fasting normally.