Identifying risk factors for postoperative hypocalcemia in primary hyperparathyroidism: 12-year experience in a...

Hypocalcemia is the most common complication following parathyroidectomy (PTX) in patients with primary hyperparathyroidism (PHPT). With asymptomatic PHPT cases increasingly comprising a larger proportion of clinical presentations, the association between preoperative symptom status and postoperative hypocalcemia risk remains poorly defined. This study aimed to identify risk factors for hypocalcemia after PTX in symptomatic vs. asymptomatic PHPT patients to enable individualized calcium management protocols.

A retrospective analysis was performed on patients with primary PHPT who underwent PTX between July 2012 and August 2024. A total of 478 patients were included and categorized into two groups based on symptomatic status at admission. Data regarding demographics, surgical details, and laboratory parameters were collected. Univariate and multivariate analyses were performed to identify factors associated with postoperative hypocalcemia in PHPT patients.

Multivariate analysis revealed that the preoperative serum chloride/calcium (Cl/Ca) ratio [odds ratio (OR) =1.104; 95% confidence interval (CI): 1.025-1.190; P=0.009], alkaline phosphatase (OR =1.002; 95% CI: 1.001-1.003; P=0.001) and female gender (OR =0.257; 95% CI: 0.103-0.641; P=0.004) were statistically significant predictors of early postoperative hypocalcemia in the symptomatic group. In the asymptomatic group, age ≤60 years (OR =0.379; 95% CI: 0.161-0.894; P=0.03) and a higher preoperative serum Cl/Ca ratio (OR =1.335; 95% CI: 1.170-1.523; P<0.001) were identified as independent predictors of early postoperative hypocalcemia.

This first stratification analysis of PHPT patients by symptomatic status identified the serum Ca/Cl ratio as a common, independent predictor of post-PTX hypocalcemia in both symptomatic and asymptomatic groups. Additionally, in symptomatic patients, alkaline phosphatase levels and female gender were associated with early hypocalcemia. Conversely, for asymptomatic patients, age ≤60 years emerged as a significant predictor.