Causes of Hypoglycemia in Children
The most common causes of hypoglycemia in children include insulin excess relative to food intake or exercise, delayed meals, medication effects, and various metabolic and endocrine disorders that affect glucose regulation.
Diabetes-Related Causes
Hypoglycemia is the most common acute complication in children with diabetes, particularly those with type 1 diabetes 1. Common causes include:
- Insulin excess: Too much insulin relative to food intake or energy expenditure 2
- Missed or delayed meals/snacks: Failure to consume planned carbohydrates 1
- Excessive physical activity: Exercise increases glucose utilization without adequate carbohydrate intake 1
- Impaired counter-regulatory response: Repeated episodes of hypoglycemia can lead to defective glucose counterregulation and hypoglycemic unawareness 1
- Nocturnal hypoglycemia: Common in children with diabetes (14-47% incidence), partly due to impaired counter-regulatory response during sleep 1
Non-Diabetes Related Causes
In children without diabetes, hypoglycemia may result from:
Hyperinsulinism
- Congenital hyperinsulinism: Genetic mutations affecting insulin regulation (SUR-1, Kir6.2, glucokinase, glutamate dehydrogenase) 3
- Transient neonatal hyperinsulinism: Often associated with maternal diabetes, large for gestational age infants 3
- Insulinoma: Insulin-producing pancreatic tumors (rare in children) 3
Hormonal Deficiencies
- Hypopituitarism: Deficiencies in growth hormone, cortisol, and other counter-regulatory hormones 4
- Adrenal insufficiency: Inadequate cortisol production 4
Metabolic Disorders
- Inborn errors of metabolism: Enzymatic defects affecting carbohydrate, protein, and fat metabolism 4
- Glycogen storage diseases: Impaired glycogen breakdown or synthesis 4
- Fatty acid oxidation disorders: Inability to use fat for energy during fasting 3
Other Causes
- Ketotic hypoglycemia: Most common form of hypoglycemia in non-diabetic children (2-6 years), related to limited substrate availability during fasting 4
- Medications: Non-insulin medications that can cause hypoglycemia (beta-blockers, salicylates) 2
- Perinatal stress: Birth asphyxia, maternal toxemia, prematurity, intrauterine growth restriction 3
- Severe malnutrition: Inadequate substrate for gluconeogenesis 4
Clinical Presentation
Symptoms vary by age and severity:
In Infants and Young Children
- Irritability, lethargy
- Feeding difficulties
- Cyanosis, tachypnea, hypothermia
- Seizures (in severe cases) 4
In Older Children
- Adrenergic symptoms: Tremors, sweating, pallor, palpitations (hypoglycemia awareness) 5
- Neuroglycopenic symptoms: Headache, confusion, behavioral changes, visual disturbances, seizures, coma 5
Risk Factors for Severe Hypoglycemia
- Young age (especially <5 years)
- Longer diabetes duration
- Intensive insulin treatment
- Previous severe hypoglycemic episodes
- Hypoglycemia unawareness
- Poor metabolic control 5, 6
Prevention and Management
Prevention strategies include:
- Regular blood glucose monitoring
- Appropriate insulin dosing relative to food intake and activity
- Carbohydrate consumption before, during, and after exercise
- Bedtime snacks to prevent nocturnal hypoglycemia 1
Treatment depends on severity:
- Mild-moderate: 20g rapidly absorbed carbohydrate
- Severe: Glucagon injection (0.5-1.0mg) or IV glucose (0.2-0.5g/kg) 5
Long-term Consequences
Severe or recurrent hypoglycemia, particularly in young children, may lead to:
- Cognitive deficits and learning disabilities
- Permanent EEG abnormalities
- Temporary impairment of cognitive function even after clinical recovery 5
For this reason, blood glucose goals may be set higher for very young children to reduce hypoglycemia risk 1.