Endocrine Abstracts

Introduction: Graves’ disease is associated with mild hypercalcemia in about 1/5th of cases. T3, through its nuclear receptor activates osteoclasts resulting in accelerated bone turnover. Although mild hypercalcemia is common in Graves’ disease, symptomatic hypercalcemia is rare. We describe a case who presented with thyrotoxic storm and hypercalcemia.

Case report: 52-year-old lady presented with thyrotoxic symptoms of weight loss, dysphagia for 2 weeks. She had noticed painless neck swelling 3 months ago. She was a hypertensive, was on amlodipine. On examination, she had tachycardia (150/min), elevated blood pressure of 170/100 mm of Hg, fine finger tremors, a goitre measuring 12x6 cm. She had a hoarse voice and was anxious. She had paraparesis of both legs. Other systemic examination was normal. Burch-Wartofsky score was 45 indicating thyroid storm. She was admitted in intensive care unit, investigations revealed suppressed TSH-0.015IU/ml, elevated free T4 >90pmol/l, free T3 >53.77pmol/l and TSH receptor antibody >40IU/l. At presentation, her serum corrected calcium level was 3.24 mmol/l (2.13-2.63), phosphorous-0.71 mmol/l, 25(OH) vitamin D was 91.4ng/ml, low PTH of 15pg/ml. Renal and liver functions, serum protein electrophoresis were normal. MRI of the spine revealed intervertebral disc prolapse at the level of L4-L5. She was started on propylthiouracil, propranolol, dexamethasone. Adequate hydration with 0.45% normal saline was done. Serum calcium, phosphorous and free T4 levels were monitored regularly. Her calcium levels gradually improved and on discharge, after 4 weeks her calcium was normalized (2.55 mmol/l). Free T4 at the time of discharge was 9pmol/l. On follow up, her thyroid functions and calcium were normal.

Conclusion: Hypercalcemia is rare in Graves’ disease and might be overlooked. In case of thyrotoxic storm, it is important to assess calcium level. High-normal vitamin D level may act as a risk factor for hypercalcemia in Graves’ disease.