Hypoglycemia as a manifestation of congenital multiple pituitary hormone deficiency in patients without growth retardation: a clinical series

Abstract

Congenital hypopituitarism is usually diagnosed in children with growth retardation. Severe life-threatening hypoglycemia and cholestasis can be early manifestations of hypopituitarism in neonates. The pituitary stalk interruption syndrome revealed by MRI confirms the diagnosis of congenital hypopituitarism.
 We report six cases of children admitted with recurrent ketotic hypoglycemia since early age. The median age of the first clinical presentation of hypoglycemia was 16 months. The median age at primary endocrinological examination was 45 months. At the first examination none of the patients had growth failure. Neonatal jaundice was noticed in four patients. Free T4 levels were decreased in all the patients (median level, 8.6 pmol/l; the lower limit of normal being 10 pmol/l), while the TSH level was normal or moderately increased, suggesting secondary hypothyroidism. Cortisol levels were low (median 92 nmol/L; range, 37—130 nmol/l). IGF-1 level was below the limit of detection (<25 ng/ml) in all patients and reached the normal values in none of patients. All children had elevated prolactin levels: 540—1778 mU/l (normal level, 90—540 mU/l). MRI of the brain revealed similar abnormalities in the chiasmal sellar region in all the patients: anterior pituitary hypoplasia, thin or interrupted pituitary stalk, ectopic neurohypophysis into the chiasm and the hypothalamic structures.
 Ketotic hypoglycemia can be the first manifestation of congenital hypopituitarism before the growth failure. Hormonal results showing secondary hypothyroidism, secondary adrenal failure, low IGF-1 and pituitary stalk interruption syndrome detected by MRI are sufficient for making the diagnosis of congenital combined pituitary deficiency in children with hypoglycemia; GH-stimulation tests could be avoided in these cases.