Introduction: X-linked hypophosphataemia (XLH) is conventionally managed with oral phosphate and active vitamin D analogues. Objectives: To evaluate long term treatment response by assessing biochemical disease activity [serum alkaline phosphatase (ALP)], radiological rickets severity score (RSS), growth and morbidity in patients with XLH on conventional therapy and assess the correlation between serum ALP and RSS. Methods: XLH patients from 3 UK tertiary centres with >= 3 radiographs one year apart were included. Data was collected retrospectively. The RSS was assessed from routine hand and knee radiographs and ALP z scores were calculated using age-specific reference data. Results: Thirty-eight (male = 12) patients met the inclusion criteria. The mean +/- SD knee, wrist and total RSS at baseline (median age 1.2 years) were 2.0 +/- 1.2, 1.9 +/- 1.2 and 3.6 +/- 1.3 respectively; and at the most recent clinic visit (median age 9.0 years, range 3.3-18.9) were 1.6 +/- 1.0, 1.0 +/- 1.0 and 2.5 +/- 1.5 respectively. The mean +/- SD serum ALP z scores at baseline and the most recent visit were 4.2 +/- 2.3 and 4.0 +/- 3.3. Median height SDS at baseline and most recent visit were -1.2 and -2.1 (p = 0.05). Dental abscess, craniosynostosis, limb deformity requiring orthopaedic intervention and nephrocalcinosis were present in 31.5%, 7.9%, 31.6% and 42.1% of the cohort respectively. There was no statistically significant (p > 0.05) correlation between ALP z scores and knee (r = 0.07) or total (r = 0.12) RSS. Conclusions: Conventional therapy was not effective in significantly improving biochemical and radiological features of disease. The lack of association between serum ALP and rickets severity on radiographs limits the value of ALP as the sole indicator of rickets activity in patients receiving conventional therapy.

Aims Congenital hyperinsulinism (CHI) is a rare condition, which is estimated to affect 1 in 25 000 newborn babies. The incidence is much higher in consanguineous parents, possibly as frequently as one in every 2500 children. From July 2017 to July 2018, we have identified 6 cases of CHI in our neonatal unit; these patients are looked after in conjunction with a specialist tertiary endocrine team. We noted a rising incidence and explored if there were any common contributory factors that may have attributed to hyperinsulinism. Methods We retrospectively reviewed the medical notes of the 6 cases. We considered factors such as gestation at birth, birth weight, ethnicity, consanguinity, presence or absence of gestational diabetes mellitus in all cases. We also looked at the insulin level and glucose load at diagnosis, whether they required treatment with diazoxide and if so the duration of treatment. Results All 6 cases met the criteria for diagnosis with a glucose load of >10 mg/kg/min and a raised insulin level. All the babies were born to non-consanguinous parents and only one of the patient’s mothers had gestational diabetes. 4 out of the 6 babies had IUGR (table 1) and most of the patients demonstrated a degree of perinatal stress. All the patients required treatment with diazoxide; 5 of the patients’ treatment was discontinued after 3–6 months as the hyperinsulinism was transient. None of the patients had genetic tests done. Conclusion We have identified an increasing incidence of congenital hyperinsulinism in our neonatal unit in the last year, the majority of which was transient. We have identified that the majority of babies had IUGR and demonstrated evidence of similar perinatal stress which are well recognised causes of transient CHI.

Summary Hypokalaemia at presentation of diabetic ketoacidosis is uncommon as insulin deficiency and metabolic acidosis shifts potassium extracellularly. However, hypokalaemia is a recognised complication of the management of diabetic ketoacidosis as insulin administration and correction of metabolic acidosis shifts potassium intracellularly. We describe the case of a 9-year-old girl with newly diagnosed type 1 diabetes mellitus presenting in diabetic ketoacidosis, with severe hypokalaemia at presentation due to severe and prolonged emesis. After commencing management for her diabetic ketoacidosis, her serum sodium and osmolality increased rapidly. However, despite maximal potassium concentrations running through peripheral access, and multiple intravenous potassium ‘corrections’, her hypokalaemia persisted. Seventy two hours after presentation, she became drowsy and confused, with imaging demonstrating central pontine myelinolysis – a rare entity seldom seen in diabetic ketoacidosis management in children despite rapid shifts in serum sodium and osmolality. We review the literature associating central pontine myelinolysis with hypokalaemia and hypothesise as to how the hypokalaemia may have contributed to the development of central pontine myelinolysis. We also recommend an approach to the management of a child in diabetic ketoacidosis with hypokalaemia at presentation. Learning points: Hypokalaemia is a recognised complication of treatment of paediatric diabetic ketoacidosis that should be aggressively managed to prevent acute complications. Central pontine myelinolysis is rare in children, and usually observed in the presence of rapid correction of hyponatraemia. However, there is observational evidence of an association between hypokalaemia and central pontine myelinolysis, potentially by priming the endothelial cell membrane to injury by lesser fluctuations in osmotic pressure. Consider central pontine myelinolysis as a complication of the management of paediatric diabetic ketoacidosis in the presence of relevant symptoms with profound hypokalaemia and/or fluctuations in serum sodium levels. We have suggested an approach to the management strategies of hypokalaemia in paediatric diabetic ketoacidosis which includes oral potassium supplements if tolerated, minimising the duration and the rate of insulin infusion and increasing the concentration of potassium intravenously (via central line if necessary).

Oral glucocorticoids (GC) preserve muscle strength and prolong walking in boys with Duchenne muscular dystrophy (DMD). Although vertebral fractures have been reported in boys taking GC, fracture rates for different GC regimes have not been investigated. The aim of this pragmatic longitudinal study was to compare growth, body mass, bone mineral density (BMD), vertebral fractures (VF) and ambulatory status in boys with DMD on daily (DAILY) or intermittent (INTERMITTENT), oral GC regimens. A convenience sample of 50 DMD boys from two centres was included in the study; 25 boys each were on the DAILY or INTERMITTENT regimen. Size adjusted lumbar spine BMD (LS BMAD), total body less head BMD (TBLH), by DXA and distal forearm bone densities by pQCT, GC exposure, VF assessment and ambulatory status were analysed at three time points; baseline, 1 and 2 years. At baseline, there were no differences in age, GC duration or any bone parameters. However, DAILY boys were shorter (height SDS DAILY = -1.4(0.9); INTERMITTENT = -0.8(1.0), p = 0.04) with higher BMI (BMI SDS DAILY = 1.5(0.9); INTERMITTENT = 0.8(1.0), p = 0.01). Over 2 years, DAILY boys got progressively shorter (delta height SDS DAILY = -0.9(1.1); INTERMITTENT = +0.1(0.6), p < 0.001). At their 2 year assessment, 5 DAILY and 10 INTERMITTENT boys were non-ambulant. DAILY boys had more VFs than INTERMITTENT boys (10 versus 2; chi(2) p = 0.008). BMAD SDS remained unchanged between groups. TBLH and radius BMD declined significantly but the rate of loss was not different. In conclusion, there was a trend for more boys on daily GCs to remain ambulant but at the cost of more VFs, greater adiposity and markedly diminished growth. In contrast, boys on intermittent GCs had fewer vertebral fractures but there was a trend for more boys to loose independent ambulation.

FGF-23 is the primary regulator of phosphate homeostasis and acts by inhibiting phosphate reabsorption in the kidney (1). Loss-of-function mutations in the gene encoding phosphate-regulating endopeptidase homolog X-linked (PHEX) results in excess circulating FGF-23, which impairs renal phosphate reabsorption causing hypophosphatemia, and decreases the synthesis of the active metabolite of vitamin D, 1,25-dihydroxyvitamin D.

Background Hypoparathyroidism is characterised by hypocalcaemia, and standard management is with an active vitamin D analogue and adequate oral calcium intake (dietary and/or supplements). Little is described in the literature about the impact of intercurrent illnesses on calcium homeostasis in children with hypoparathyroidism. Methods We describe three children with hypoparathyroidism in whom intercurrent illnesses led to hypocalcaemia and escalation of treatment with alfacalcidol (1-hydroxycholecalciferol) and calcium supplements. Results Three infants managed with standard treatment for hypoparathyroidism (two with homozygous mutations in GCMB2 gene and one with Sanjad-Sakati syndrome) developed symptomatic hypocalcaemia (two infants developed seizures) following respiratory or gastrointestinal illnesses. Substantial increases in alfacalcidol doses (up to three times their pre-illness doses) and calcium supplementation were required to achieve acceptable serum calcium concentrations. However, following resolution of illness, these children developed an increase in serum calcium and hypercalciuria, necessitating rapid reduction to pre-illness dosages of alfacalcidol and oral calcium supplementation. Conclusion Intercurrent illness may precipitate symptomatic hypocalcaemia in children with hypoparathyroidism, necessitating increase in dosages of alfacalcidol and calcium supplements. Close monitoring is required on resolution of the intercurrent illness, with timely reduction of dosages of active analogues of vitamin D and calcium supplements to prevent hypercalcaemia, hypercalciuria and nephrocalcinosis.

Aims There is limited data on the psychological sequelae of obesity in paediatric patients. We aimed to assess the prevalence of psychological comorbidities in obese paediatric patients and to explore whether patient and parent motivation scores can be used as a predictor for weight loss. Methods Internationally validated self-report questionnaires were offered to 19 patients and their parents from a tier 3 paediatric obesity clinic. These included the Paediatric Index of Emotional Distress (PI-ED); Beck Youth Inventory™ exploring self-perceptions of competency, potency and self-worth; Paediatric Quality of Life Inventory (PaedsQL™); Parent-Proxy report (PaedsQL™Parent) and two in-house derived motivation questionnaires for parents and patients. Results 14 patients completed the PI-ED, of which more than half (57%) reported emotional distress (5=female, 3=male). 15 patients completed the Beck Youth Inventory™ of which 53% reported low self-esteem (4=female, 4=male). 17 patients completed QoL scores and scored on average below normal cut offs for the social and physical domains, as well as for overall psychosocial health and overall QoL (total score). The parents of these children also reported below normal cut offs for all domains except schooling. Those aged <10 years reported the highest QoL scores. Females reported significantly lower scores for emotional, social and overall QoL domains, particularly those between 10–15.9 years. 18 children and 19 parents completed motivation scores. All of those reported medium to high motivation with a non-significant correlation between reduction in BMI SDS (z-score) and increased patient and parent motivation scores (p = 0.19 and p = 0.47 respectively). Discussion/Conclusion More than half of obese paediatric patients in our cohort experience a high prevalence of emotional distress and low self-esteem. Obese paediatric patients are at risk of experiencing reduced QoL. Females between the ages of 10–15.9 years are the most vulnerable to experiencing psychological comorbidities within this cohort. Initial observations may suggest high motivation scores are a positive indicator for weight change but more research should be carried out to establish a link.

Searchable abstracts of presentations at key conferences on calcified tissues ISSN 2052-1219 (online)

SummaryCongenital Hyperinsulinism (CHI) is a rare but important cause of hypoglycaemia in infancy. CHI is a heterogeneous disease, but has a strong genetic basis; a number of genetic causes have been identified with CHI in about a third of individuals, chiefly in the genes that code for the ATP sensitive K+ channels (KATP) in the pancreatic β‐cells. Rapid KATP channel gene testing is a critical early step in the diagnostic algorithm of CHI, with paternal heterozygosity correlating with the occurrence of focal lesions. Imaging investigations to diagnose and localize solitary pancreatic foci have evolved over the last decade with (18)F‐DOPA PET‐CT scanning as the current diagnostic tool of choice. Although clinical management of CHI has improved significantly with the application of genetic screening and imaging investigations, much remains to be uncovered. This includes a better understanding of the molecular mechanisms for dysregulated insulin release in those patients without known genetic mutations, and the development of biomarkers that could characterize CHI, including long‐term prognosis and targeted treatment planning, i.e. ‘personalised medicine’. From the perspective of pancreatic imaging, it would be important to achieve greater specificity of diagnosis not only for focal lesions but also for diffuse and atypical forms of the disease.

P/THU/01 Impaired 24-hour blood pressure variation and endothelial function in adolescents with type 1 diabetes L. Machnica, G. Deja, L. Czupryniak, M. Pawlowski, A. Borkowska & P. Jarosz-Chobot Upper Silesia Child Health Center, Pediatric Endocrinology and Diabetes, Katowice, Poland, Medical University of Silesia, Pediatric Endocrinology and Diabetes, Katowice, Poland, Medical University of Lodz, Diabetology and Metabolic Diseases, Lodz, Poland