Phenotype-specific Severity and Intraoperative Predictors of Hypocalcaemia in Primary Hyperparathyroidism: Evidence from an Indian Cohort
Sanjay Kumar, Surjeet Dwivedi, Naresh K. Saidha, Debashish Mukherjee, Varun K. Agrawal, Amiy Arnav, Mandeep SharmaAbstract
Introduction:
In India, primary hyperparathyroidism (PHPT) continues to present mainly with symptomatic and biochemically severe disease. Phenotype-specific severity and intraoperative predictors of postoperative hypocalcaemia remain insufficiently defined.
Methods:
We retrospectively analysed 66 consecutive patients with biochemically confirmed PHPT who underwent parathyroidectomy at a tertiary referral centre from January 2023 to December 2024. Clinical phenotypes were compared for biochemical severity. Preoperative localisation by ultrasonography (USG), Technetium Tc-99m sestamibi, and selective four-dimensional computed tomography (4D-CT) was assessed. Excised gland weight was evaluated as an intraoperative predictor of postoperative biochemical hypocalcaemia in the absence of intraoperative parathyroid hormone (PTH) monitoring.
Results:
Presentation was symptomatic in 52/66 patients (78.8%). The skeletal phenotype showed the greatest biochemical burden, with higher calcium and PTH values in key adjusted pairwise comparisons. USG and sestamibi correctly localised abnormal glands in 57/66 (86%) and 54/66 (82%) patients, respectively; concordant USG plus sestamibi correctly localised them in 50/66 (76%) patients. 4D-CT, performed selectively in 12 patients, correctly localised them in 6/12 (50%) patients. Postoperative biochemical hypocalcaemia occurred in 17/66 patients (25.8%). Age, preoperative calcium, PTH, alkaline phosphatase, and 25-hydroxyvitamin D did not differ between hypocalcaemia groups. Excised gland weight was higher in patients with hypocalcaemia (median 5.2 g vs. 2.3 g;
Conclusion:
In this cohort, PHPT remained predominantly symptomatic, with skeletal disease representing the highest biochemical burden. USG and sestamibi reliably localised gland abnormalities in most patients. Excised gland weight may serve as a practical intraoperative marker of hypocalcaemia risk where intraoperative PTH monitoring is unavailable.