Endocrine Abstracts

Section 1: Case history: An 18 year old young man with a background of several years’ ADHD (Attention Deficit Hyperactivity Disorder) and moderate learning disability presented generally unwell, with recent weight loss, abdominal pain, vomiting and poor oral intake in May 2019. He had been unsettled for some time with his mother convinced that his current condition warranted further investigation. When blood tests were done, severe hyponatraemia and hyperkalaemia were found and urgent referral made to the hospital. His past medical history was of preterm labour at 27 weeks, developmental delay, delayed speech and language development, coordination difficulty and cholesteatoma. He was on Methylphenidate 10 mg BD and Medikinet XL 40 mg OD, under follow up at the Paediatric clinic for his ADHD. His weight and height changed from 24 kg, 132 cm in 2010 to 40 kg, 160 cm in 2015 and 56 kg, 182 cm in March, 2019. On admission, his weight was 52 kg, examination revealed hyperpigmentation with pulse 103 and BP 94/65 mmHg.

Section 2: Investigations: On admission various blood tests were performed including a random cortisol, assessment of osmolality; later a short synacthen test (SST) and test for adrenal antibodies were organised.

Section 3: Results and treatment: The results on admission showed Sodium 122, K 6.4, Urea 19.4, Creatinine 154, Calcium 2.49, Albumin 43, Serum osmolality of 279 mmol/Kg (275–295), Urine osmolality 784 mmol/Kg and Random Cortisol of 271 nmol/l. The SST confirmed adrenal failure; Cortisol level 0 min 324, 30 min 336 and 60 min 342. Renin was 85 mU/l (5.4–60). TFTs (thyroid function tests); TSH 1.86, T4 17.6, TTG 0.8 u/ml (0–6.9), and 17OH Progesterone 1.9 nmol/l (0–5) were within range. The adrenal cortex autoantibodies result was positive. He was treated with Hydrocortisone 50 mg IV TDS and Fludrocortisone 100 mcg OM. Clinical and biochemical improvement took place, with electrolytes back to normal after 5 days of treatment. He is now on replacement oral Hydrocortisone 20 mg/24 h and Fludrocortisone 100 mcg and is under the Adult Endocrinology clinic.

Section 4: Conclusions and points for discussion: ADHD can present with a variety of symptoms and there is some evidence of HPA-axis dysregulation with associated variability in cortisol dynamics. Current guidelines for evaluating patients with ADHD do not suggest extensive or regular endocrine screening, which may lead to delays in diagnosis. In those treated for ADHD, altered behaviour and/or a change in physical development may warrant careful elucidation, especially for Addison’s disease.