Endocrine Abstracts

Introduction: Post-surgical hypoparathyroidism (PoSH) is common after thyroidectomy. Most cases recover within 6 months, but several require long-term supplementation with calcium and activated vitamin D. When PoSH persists beyond 6 months, it is considered to be ‘long-term’ or ‘permanent’. However, few studies have demonstrated recovery beyond this time period.

Aim: Aim of this study is to determine the frequency of late recovery in this group and factors that can predict this.

Methods: Adult patients undergoing total or completion thyroidectomy between 2009-2018 were included in this cohort prospective observational study. Records of patients who met certain inclusion criteria (started on calcium or activated vitamin D, or day 1 adjusted calcium <2.1 mmol/l, or day 1 PTH <1.6 pmol/l) were reviewed to identify those with PoSH at 6 months. Demographic, biochemical, surgical, pathological, and clinical follow-up data is described and analysed.

Results: Out of 911 patients undergoing thyroidectomy, 270 met inclusion criteria. Of these, 192 were started on supplements and 138 (71.9%) recovered within six months. From the remaining 54 patients (females: males=46:8), 21 had ongoing PoSH (minimum follow-up 3 years, median follow-up 4.5 years). However, a significant number of patients (n = 19 [47.5%]) were weaned off all supplements and achieved remission (median recovery at 1.3 years, most delayed recovery at 4.8 years). All of those who recovered had a PTH of ≥1.6 pmol/l at/beyond 6 months. There was no difference in age, gender, diagnosis, type/extent of surgery, or calcium levels between the two groups.

Conclusions: Recovery from PoSH is common beyond 6 months, raising the question of whether 6-month threshold to define long-term PoSH is appropriate? In patients with PTH level of ≥1.6 pmol/l at/after 6 months, the chances of recovery are high. Therefore, attempts should be made to wean off supplements in this group.