Hypoglycemia in Children Referred to a Tertiary Care Pediatric Endocrine Clinic: Age-Dependent Etiological Variations

Introduction: Diagnosing hypoglycemia in infants and children presents significant challenges. Our objective was to elucidate the diagnoses and clinical features of children with hypoglycemia referred to a pediatric endocrine tertiary clinic. Methods: This was a retrospective study of 154 children (0-18 years old) presenting with hypoglycemia, during 1992-2018. Results: The cohort was divided by clinical diagnosis into six groups: ketotic hypoglycemia (n = 45, 29.2%), congenital hyperinsulinemic hypoglycemia (n = 35, 22.7%), transient hyperinsulinemic hypoglycemia (n = 28, 18.2%), metabolic disorder (n = 14, 9.1%), systemic disease/syndrome (n = 15, 9.7%), and hormone deficiencies (n = 8, 5.2%). Two patients had insulinoma, and in 7 (4.5%), no diagnosis was elucidated. At diagnosis, 58 (37.7%) were <1 month old, 23 (14.9%) aged 1-12 months, 58 (37.7%) aged 1-6 years, and 15 (9.7%) aged 6-18 years. Hypoglycemia etiology varied among neonates, infants, and children. In 8 patients, hypoglycemia was asymptomatic. Of 47 patients who completed a diagnostic fast, 31 became hypoglycemic, yet a significant added value for diagnosis was only found in 14 (29.8%) patients. Conclusions: Hypoglycemia etiology in children is heterogeneous and varies by age. Any hypoglycemia measured in a child should be seriously evaluated as 7% are asymptomatic. Workup should be tailored based on age, and clinical, biochemical, and imaging findings. Despite extensive workup, in a significant number of patients the mechanism underlying pediatric hypoglycemia remains an enigma. This emphasizes the unmet needs and challenges in studying pediatric hypoglycemia.