Hypoglycemia in Children

Hypoglycemia, although rare in childhood beyond the newborn period, remains a vexing problem for the pediatrician. First, the symptoms may be vague and nonspecific, thus making diagnosis particularly dependent on a high index of suspicion. Second, the pathogenic mechanisms that result in hypoglycemia are as numerous and complicated as the physiologic mechanisms that maintain euglycemia. Finally, although most patients have no permanent sequelae, a catastrophic episode of hypoglycemia can cause neurologic deficit and mental retardation. In this brief review, the most common cause for hypoglycemia, namely, insulin-dependent type I diabetes mellitus, will not be considered. Instead, we will focus on those metabolic disorders that result directly in a loss of the ability to maintain normal serum glucose concentrations.SYMPTOMSIn the older infant (older than 2 months), child, and adult, a rapid decrease in blood glucose to levels less than 40 mg/dL (2.2 mmol/L) may produce hunger and trigger an excessive release of epinephrine, causing weakness, anxiety, cold sweat, inward trembling and tachycardia. These adrenergic symptoms tend to occur in persons with postprandial hypoglycemia. In contrast, fasting hypoglycemia generally is progressive and gradual and produces neuroglycopenic symptoms which include headache, mental dullness, fatigue, confusion, abnormal behavior or psychosis, amnesia or other neurologic deficit, seizures, or frank coma.