Endocrine Abstracts

Introduction: Parathyroidectomy is the treatment of choice for patients with primary hyperparathyroidism who have significant hypercalcemia and/or end-organ damage. The incidence of postoperative hypocalcaemia is 25–90% in patients with evidence of radiological evidence of parathyroid disease, 0–6% without. In most patients it is mild, but in some, it can cause significant morbidity. It has been attributed as ‘hungry-bone syndrome’ and attempts have been made to identify predictors with a view to reducing its incidence.

Methods: We retrospectively reviewed patients who had parathyroidectomy over the past 3 years at our hospital and assessed the frequency of post-operative hypocalcaemia (serum calcium <2.1 mmol/l). We correlated the occurrence of hypocalcaemia with predictors known to influence the frequency of its occurrence.

Results: 46 patients had surgery over 3-year period. Mean age 63 years, 12 (26%) were males. Mean preoperative calcium, parathyroid hormone, and alkaline phosphatase were 2.95 mmol/l (2.1–2.6), 20.53 pmol/l (1.6–7.2), and 102 IU/l (30–130) respectively. Pre-operative vitamin D level was recorded in 22 patients and 10/22 had significant vitamin D deficiency (<25 nmol/l). Mean weight of parathyroid adenoma was 2.5 g. Nine patients (20%) had post-operative hypocalcaemia with mean calcium of 1.92 mmol/l (+0.33). All patients had an eventless course and spontaneous recovery. There was no statistically significant difference between those who developed hypocalcaemia and those did not, in terms of mean age, gender distribution, pre-operative serum calcium, parathyroid hormone and alkaline phosphatase or with the weight of parathyroid adenoma (P>0.05 for all). Unfortunately as pre-operative vitamin D level was only available in 50% of patients; its correlation with hypocalcaemia could not be ascertained reliably.

Conclusion: The frequency of post parathyroidectomy hypocalcaemia was high in our patients. This may be related to high prevalence of vitamin D deficiency. However we did not find correlation between the occurrence of post-operative hypocalcaemia and any of its known predictors.