Primary Hyperparathyroidism in Patients With Nephrolithiasis: Experience From a Tertiary Center

Background: Primary hyperparathyroidism (PHPT) is an important but under-recognized cause of nephrolithiasis. Despite clinical guidelines recommending biochemical screening for PHPT in stone-forming patients, especially those with hypercalcemia, screening and referral patterns remain inconsistent in routine practice. This study aimed to evaluate adherence to PHPT screening recommendations among adult stone-forming patients and to determine the prevalence and characteristics of confirmed PHPT cases in a tertiary Saudi center. Methods: A retrospective cohort study was conducted at King Abdulaziz Medical City (KAMC), Riyadh, including adult Saudi patients diagnosed with nephrolithiasis between January 2019 and December 2023. Data were extracted from the BestCare electronic health record system. Patients were classified according to serum calcium status and parathyroid hormone (PTH) testing. PHPT was defined as persistent hypercalcemia with inappropriately elevated PTH after exclusion of secondary causes. Statistical analysis was performed using SPSS version 26. Results: A total of 1,229 patients were included (800 males, 429 females). Females had a significantly higher body mass index (BMI) (P < 0.001) and were more likely to have kidney stones ≥ 10 mm (P = 0.004), while males had significantly higher creatinine levels (P < 0.001) and more ureteral stones (P < 0.001). PTH screening was performed more frequently in females (53.2%) than males (46.8%) (P < 0.001). Although PHPT was diagnosed more frequently in females, the gender difference in PHPT prevalence was not statistically significant (P = 0.336). Referral to endocrinology was significantly more common among those diagnosed with PHPT (P = 0.046), yet overall referral rates remained low. Conclusion: There is significant under-screening for PHPT among patients with nephrolithiasis, particularly among hypercalcemic individuals. Gender-based disparities in evaluation and referral patterns were observed. These findings emphasize the need for improved clinician awareness and systematic screening protocols to enhance early detection and management of PHPT in stone-forming patients.