Endocrine Abstracts

Case history: A 34 year old Chinese male was referred by GP as routine blood test which was done as part of investigation for ongoing hair loss that revealed hypocalcaemia. Patient was asymptomatic with no tingling sensation, numbness or anaesthesia. There was no history of carpopedal spasm, muscle pain or cramps. He does not give any history of symptoms suggestive of malabsorption. His PMH include Mild asthma and Eczema for which he was not on any regular medication. Social history of note he lives with his parents and have no partner. He works in IT and stays mostly indoors. He does not smoke or drink alcohol. There is no family history of problem with calcium or any bony deformity. On examination Chvostek’s and Trousseau’s sign was negative. No bony deformity noted. Systemic examination was essentially normal.

Investigations: FBC- Normal, Normal renal function, Adjusted calcium- 1.57, PTH 75.7, Phosphate 1.0, Magnesium 0.81, Vitamin D 16.ALP 117 TSH 2. ECG-Normal sinus rhythm and QTc. Vitamin B12, folate and ferritin- Normal.

Results and treatment: The results supported a clinical diagnosis of secondary hyperparathyroidism due to vitamin D deficiency. Patient was started on Cholecalciferol 40 000 units once a week for 8 weeks then 20 000 units once a week for 8 weeks. He was also started on Calcium carbonate 1000 mg three times daily for 3 months. Patient was subsequently followed up in the endocrine clinic for 2 years where he missed couple of his appointments. His Vitamin D level normalised after initial replacement and remained between 71 to 87. His Adjusted calcium remained low between 1.9 and 2. The patients PTH remained high and was 24.2. After initial vitamin D replacement patient was on Cholecalciferol 10 000 units OD and Calcichew 2 tablet daily which was continued for 2 years with patient denying any compliance issue. His most recent blood test showed PTH 15.5, Adjusted calcium 2.1 and Vitamin D 135. All other biochemical test was normal.

Discussion: Differential diagnosis includes 1) Hypocalcaemia due to Vitamin D deficiency with secondary hyperparathyroidism or Pseudohypoparathyroidism Type 2 or 1b.Point for discussion-1) Is there any other test will be helpful to confirm the diagnosis like PTH infusion and measurement of urinary cAMP(where done in UK) or Xray hand or measure 1 25 OH Vit D and genetic test for Pseudohypoparathyroidism. 3) Is there any other treatment that can achieve normocalcaemia like alpha-calcidol.