Endocrine Abstracts

Introduction: Roux-en-Y gastric bypass (RYGB) places patients at an increased risk of hypocalcemia due to the reduction in calcium absorption (because the procedure bypasses the duodenum and jejunum) and vitamin D deficiency. Subsequent thyroid surgery increases the risk of severe hypocalcemia due to potential post-operative hypoparathyroidism. Only a few cases have been published before of this kind of treatment-challenging hypocalcaemia.

Case report: We report the case of a 31-year-old woman with a previous RYGB, who suffered severe and symptomatic chronic hypocalcaemia after total thyroidectomy. Six months after the surgery, corrected calcium level had severely decreased (5.2 mg/dl) and the patient related generalised muscle cramps, labile mood and increased anxiety. She required aggressive therapy with oral calcium and calcitriol (highest dose: 12 g of calcium carbonate and 8 μg of calcitriol per day) and frequent calcium infusions, but there was no improvement in serum calcium level. Due to the lack of response to standard therapy, teriparatide treatment was started (first with s.c. injections and thereafter with a multipulse s.c. infusor) but the results were disappointing. As there was no response to different medical treatments, reversal of RYGB was performed with no complications and a subsequent sustained increase in serum calcium level.

Conclusions: This case shows that patients with postoperative hypoparathyroidism and RYGB have increased risk of severe recalcitrant symptomatic hypocalcaemia. In our case teriparatide was ineffective but, as this is the first patient reported, more results are needed to evaluate properly the effect of teriparatide in this kind of hypocalcaemia. The reversal of RYGB may be an optimal treatment, if medical management has failed, because the surgery recovers an adequate absorption of calcium and vitamin D from previously bypassed duodenum and proximal jejunum.