Evaluation for Primary Hyperparathyroidism in Patients Who Present With Nephrolithiasis

Area of Science:

• Nephrology
• Endocrinology
• Surgical Oncology

Background:

• Primary hyperparathyroidism (PHP) incidence may be underestimated.
• Nephrolithiasis can be an indicator of PHP requiring parathyroidectomy.
• Current diagnostic and referral pathways for PHP in nephrolithiasis patients are unclear.

Purpose of the Study:

• To determine the proportion of nephrolithiasis patients with measured serum calcium levels.
• To assess parathyroid hormone (PTH) measurement rates in hypercalcemic patients.
• To evaluate the time to referral for definitive management of diagnosed PHP.

Main Methods:

• Retrospective review of adult patients with nephrolithiasis (July 2016 - December 2018).
• Exclusion of patients with prior nephrolithiasis, urinary tract anomalies, or on calciuretics.
• Assessment of serum calcium and PTH levels, and surgical referrals; univariate analysis performed.

Main Results:

• Of 968 eligible patients, 64.0% had calcium measured; 1.58% were hypercalcemic.
• Of hypercalcemic patients, 66.7% had PTH measured, all indicating PHP.
• Referral to surgery occurred in 62.5% of PHP patients, with significant delays (median 270 days).

Conclusions:

• A significant proportion of nephrolithiasis patients are not evaluated for hypercalcemia or PHP.
• Delayed diagnosis and referral for PHP in these patients can prolong time to parathyroidectomy.
• Electronic health record alerts or automated reflex testing could enhance diagnostic and referral processes.