ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Endocrine Abstracts (2019) 66 P63 | DOI: 10.1530/endoabs.66.P63

The use of 'Hypopaks' in the investigation of hypoglycaemia in children

Rachel Beckett1, Kirsty Spence2, Gillian Hamilton3, Mohammad Alcheikh1, Siobhan O’Sullivan1, Grainne Connolly3, Margaret McDonnell4, Noina Abid1 & Emmeline Heffernan1

1Royal Belfast Hospital for Sick Children, Belfast, UK; 2Regional Endocrine Laboratory, Belfast, UK; 3Regional Metabolic Laboratory, Belfast, UK; 4Clinical Biochemistry Laboratory, Belfast, UK

Introduction: When hypoglycaemia (blood glucose <2.6 mmol/l) is detected in a child a ‘Hypopak’ is sent, which tests for blood glucose, lactate, hydroxybutyrate, insulin, growth hormone, cortisol, amino acids, acylcarnitines, and urine organic acids. We aimed to determine whether samples were sent appropriately and completely, and whether a diagnosis ensued.

Methods: All Hypopak samples received by the laboratory between 1/4/17 and 31/3/18 were reviewed. Samples with glucose ≥3 mmol/l or unrecorded were excluded. We used data handwritten on request forms and the Northern Ireland Electronic Care Record for information on the event and follow up.

Results: 223 Hypopaks were received from 210 patients. 51% were from girls and 67% <3 years. Only 36% had complete results for all tests. 113 samples (51%) had glucose <3 mmol/l (3 samples <1 mmol/l), of these 83% had all endocrine tests completed. 25 samples (23 patients) had detectable insulin, 3 following dextrose administration and 9 from neonates. 10 patients had low/undetectable ketones. Of these, 1 had dumping syndrome, 1 was following dextrose, 1 had a metabolic disorder and the remainder were neonates. 24 samples (23 patients) had cortisol <450 nmol/l (mean and median both 212 nmol/l, range 24–435 nmol/l). Subsequently, 6 patients had a synacthen test (resulting in 2 diagnoses of ACTH deficiency), but 14 had no further testing. 3 patients had repeat cortisols sent (all >400 nmol/l). Defining sufficient growth hormone as 6.7 ng/ml, 76 samples had insufficient levels (6 samples <1 ng/ml). 1 patient is on growth hormone for septo-optic dysplasia (previously diagnosed) and 1 has IGF1 and IGFBP3 deficiency (not on growth hormone and had 5 samples sent). 14 patients with growth hormone <6.7 ng/mg are attending/have been discussed with Endocrinology. Following Hypopak investigations 2 patients were diagnosed with mitochondrial complex I deficiency.

Conclusions: Hypoglycaemia is most common in the <3 years age group but samples are frequently taken inappropriately and incompletely. Patients are often not followed up once the result is available and very few patients are diagnosed with an Endocrine or Metabolic disorder. We propose delaying analysis of some more expensive tests until blood glucose is confirmed <3 mmol/l and developing a guide for result interpretation and follow up.