Endocrine Abstracts

JOINT2635

Introduction: Congenital hypopituitarism is defined as the deficiency of one or more hormones produced by the pituitary gland. Diagnosis in neonates is often challenging as they often present with non-specific symptoms. We describe a case of a 7-week-old baby girl with congenital hypopituitarism presenting with hypoglycemia.

Case: A 7-week-old baby girl presented to the Children’s Emergency for jitteriness, increasing lethargy and poor feeding. She was born full term with a birth weight of 3.4kg. Postnatally, she had hypoglycemia and conjugated hyperbilirubinemia diagnosed in another hospital, but was lost to follow-up after discharge. At presentation in the emergency at 7 weeks old, baby was jittery with poor peripheral perfusion. She was dehydrated with depressed fontanelles. Her tone was increased with brisk reflexes. She was not hyperpigmented, not dysmorphic and had normal female genitalia. Blood sugar at presentation was 2.4 mmol/L. At time of hypoglycemia, baby’s beta-hydroxybutyrate was low at <0.6 mmol/land her urine ketones were trace in the urine dipstick. Insulin production was suppressed at <1.6 mU/l(2.6 – 24.9) and C-peptide was low at 25 pmol/l(70-1448). Cortisol was inappropriately low at 116 nmol/l(14-458) and growth hormone level was 1.58mg/l(0.12 – 7.79). Lactate was normal at 1.6 mmol/l(0.5 – 2.2), sodium 141 mmol/l(133-144), potassium 6.1 mmol/l(3.6 – 5.8), chloride 111 mmol/l(97-110), bicarbonate 17 mmol/l(16-29), urea 7.8 mmol/l(1.2-6), creatinine 24 umol/l(11-36), ALT 130 U/l(6-51), AST 232 232 U/l(23-83), total bilirubin 164 umol/l(1-12) and direct bilirubin 130 umol/l(<5). Her plasma concentrations of several acylcarnitines were elevated. Free carnitine was within normal limits. Her urine organic acid revealed that the excretions of ketone bodies were markedly elevated in the presence of a moderate dicarboxylic aciduria (C6>C8>Cl0) and slight lactic aciduria. Overall, this profile was not indicative of a specific disorder and is suggestive of severe ketosis. MRI pituitary showed hypoplasia of the pituitary gland. Baby was subsequently started on hydrocortisone, thyroxine and growth hormone replacement, and was discharged well.

Conclusion: Hypoglycemia seen in hypopituitarism is typically ketotic. In this case report, this baby presented with hypoglycemia with low beta-hydroxybutyrate (the predominant ketone body) and urine ketones despite low insulin level and high free fatty acids. The presence of ketones was instead detected in her plasma acylcarnitines profile and urine organic acids, which was consistent with her subsequent diagnosis of central hypocortisolism.