ESPE Abstracts

Introduction: In hypoparathyroidism and pseudohypoparathyroidism, impaired parathyroid hormone (PTH) function leads to hypocalcaemia, often presenting in children with acute symptoms such as tetany, seizures, hyperreflexia. High-dose calcium supplementation is usually necessary. However, beyond severe symptoms relief, the primary goal of treatment should be to maintain serum calcium levels in the lower quartile of normal range, in order to prevent nephrocalcinosis, nephrolithiasis and arterial calcifications. These adverse effects should be closely monitored during follow-up.

Objective: Identifying clinical and laboratory findings at presentation in children with hypocalcaemia. Reviewing the initial treatment approach and complications surveillance to identify possible failures needing improvement, in order to set up an appropriate follow-up protocol.

Methods: Retrospective cohort of paediatric patients with hypocalcaemia due to PTH disorders during the last 20 years followed in a tertiary hospital Paediatric Endocrinology Unit. Clinical and demographic variables were analysed at diagnosis and at last visit. Kidney ultrasound, brain CT scans and EKG were also reviewed.

Results: The cohort included 17 patients, 58% males. Median age at diagnosis was 8 years (range: 5 days to 16 years). Main diagnosis were: DiGeorge Syndrome (6/17), pseudohypoparathyroidism (5/17), primary hypoparathyroidism (4/17), Barak syndrome (1/17) and activating calcium-sensing receptor (CaSR) mutation (1/17). The main symptoms at admission were: tetany (8/17), seizures (7/17), Chvostek sign (3/17), abdominal pain (2/17). Electrocardiographic abnormalities were also found in 5 children. Mean serum levels at presentation were: corrected calcium 6,9 ± 1.51 mg/dL, phosphate 6,9 ± 2,3 mg/dL, magnesium 1,75 ± 0,15 mg/dL. PTH (RV: 11,3 – 60,0pg/mL) was either increased in pseudohypoparathyroidism (498,1 ± 243,8pg/mL) or decreased in hypoparathyroidism (12 ± 13,7pg/mL). At diagnosis most patients (12/17) required hospitalization for IV calcium correction. Subsequent therapeutic intervention comprised oral calcium and vitamin D supplementation, with calcitriol as the most chosen (7/17). Frequent therapy adjustments were needed to achieve adequate calcium levels. Mean follow-up time was 4 years (from 5 months to 13 years since presentation). Renal ultrasound (n = 8) showed 1 patient with renal lithiasis and 1 with nephrocalcinosis. Brain CT scan (n = 8) revealed 4 patients with brain calcifications. Cardiac conductance abnormalities were seen in 5 patients.

Conclusions: Normalization of calcium metabolism is difficult to manage clinically in order to prevent acute and long-term complications. Hospital admission is usually necessary at diagnosis and high doses of oral calcium and calcitriol are needed. Consistent follow-up and clearly outlined guidelines are essential.