# Impact of thyroid volume on serum ionized calcium and PTH levels after total thyroidectomy

## TL;DR

This study examines how thyroid gland volume affects calcium and PTH levels after total thyroidectomy, finding a marginal link with calcium but not PTH.

## Contribution

The study provides new insights into the relationship between thyroid volume and postoperative hypoparathyroidism risk.

## Key findings

- A reduction in PTH and ionized calcium levels was observed postoperatively.
- No significant association was found between thyroid volume and PTH levels.
- A marginal association was found between thyroid volume and changes in ionized calcium levels.

## Abstract

The relationship between thyroid gland volume and hypoparathyroidism after total thyroidectomy remains controversial.

To evaluate thyroid gland mass as a risk factor for hypoparathyroidism after total thyroidectomy.

A Retrospective cross-sectional observational study was conducted at Centro Universitário Lusíada (UNILUS), Santos/SP, Brazil.

Patients undergoing total thyroidectomy between January 2022 and September 2023 were retrospectively evaluated for serum levels of ionized calcium and ultrasensitive parathyroid hormone (PTH), measured preoperatively and 30–60 days postoperatively, and thyroid mass, obtained by weighing the specimen.

A total of 174 patients were evaluated, with a predominance of women (89.7%), a median age of 50.5 years, and a median goiter volume of 36.3 mL. A reduction in both PTH and ionized calcium levels was observed in the postoperative period compared with the preoperative period (P < 0.05). No significant changes were observed in PTH levels and volume (P = 0.481). For calcium, there was a tendency towards an association between volume measurements and its change between the pre- and postoperative periods, which was marginally significant (P = 0.051).

There was a marginal association between volume and changes in pre- and postoperative ionized calcium levels, but no significant association with pre- and postoperative PTH measurements.