Parathyroid hormone of ≥1.6 pmol/L at 6 months is associated with recovery in ‘long-term’ post-surgical hypoparathyroidism

Abstract

Objective: Post-surgical hypoparathyroidism (PoSH) usually settles within few months after thyroid surgery, but several require long-term supplementation with calcium/activated vitamin D. When PoSH persists beyond 6 months, it is considered ‘chronic’ or ‘permanent’, however, late recovery has been reported. The aim of this study was to determine the frequency of late recovery and explore factors predicting late recovery of parathyroid function. Methods: Adult patients undergoing total/completion thyroidectomy between 2009-18 were included in this retrospective cohort observational study. The records of patients with evidence of PoSH were reviewed to identify those with persisting PoSH at 6 months. Demographic, biochemical, surgical, pathological, and clinical follow-up data was collected and analysed. Results: Out of 911 patients undergoing thyroidectomy, 270 were identified with PoSH. Of these, 192 were started on supplements and 138 (71.9%) recovered within six months. Of the remaining 54 patients, 35 had ongoing PoSH with median (range) follow-up of 3.4 (0.5-11.1) years. Nineteen patients were weaned off supplements and achieved remission at median (range) follow-up of 1.3 (0.6-4.8) years. All of those who recovered had a PTH of ≥1.6 pmol/L at 6 months. There was no difference in age, gender, diagnosis, type, and extent of surgery between those who did and did not show late recovery. Conclusions: Recovery from PoSH is common beyond 6 months, raising question whether 6-month threshold to define ‘long term’ PoSH is appropriate. The chances of recovery are high (~50%) in patients with PTH level ≥1.6 pmol/L at 6 months, where attempts at weaning may be focussed.

Management of Postthyroidectomy Hypoparathyroidism and Its Effect on Hypocalcemia‐Related Complications: A Meta‐Analysis

“…A total of 1743 articles were screened (Figure 1) and 237 full‐text articles were assessed for eligibility. After careful selection of the articles, 66 studies were eligible for the final synthesis and were included in this review 10,14,23,24,27‐88 …”

Impact of autofluorescence for detection of parathyroid glands during thyroidectomy on postoperative parathyroid hormone levels: parallel multicentre randomized clinical trial

“…Some 16 patients were still being treated for hypoparathyroidism after 6 months, 6 (2.4 per cent) in the intervention group and 10 (4.2 per cent) in the control group. The 6-month threshold is well established; however, it is known that some patients may recover beyond that time point 33 , although, importantly, the secretory reserve of the parathyroid glands in such patients is not known.…”

Autofluorescence-Guided Total Thyroidectomy in Low-Volume, Nonparathyroid Institutions

“…In practice, this meant that all patients who received active vitamin D postoperatively were considered as having immediate hypoparathyroidism, whereas patients who still received active vitamin D 1 year following surgery were considered as having permanent hypoparathyroidism. One year was used as a cutoff instead of 6 months due to the possibility for late PG recovery beyond 6 months post surgery . Patients who solely received calcium supplementations postoperatively were not considered to have hypoparathyroidism as calcium and cholecalciferol supplementations are widely used in Denmark, even by healthy individuals, due to the limited sun exposure.…”

“…One year was used as a cutoff instead of 6 months due to the possibility for late PG recovery beyond 6 months post surgery. 35 Patients who solely received calcium supplementations postoperatively were not considered to have hypoparathyroidism as calcium and cholecalciferol supplementations are widely used in Denmark, even by healthy individuals, due to the limited sun exposure. Normocalcemia was defined as plasma ionized calcium concentrations in the normal range (1.18-1.32 mmol/L).…”