Endocrine Abstracts

Background: PHPT is the leading cause of hypercalcemia in outpatients. Its clinical presentation varies from asymptomatic forms to renal or bone complications. The only curative treatment is surgical resection, and delayed diagnosis can lead to serious morbidity.

Objective: Identify the presence of PHPT at least one year prior to referral to endocrinology consultation. Secondly, determine whether diagnostic delay leads to increased complications.

Methods: Retrospective observational study. We analysed electronical records from a tertiary referral center in 116 patients with PHPT that underwent surgery between 2015 and 2018. Age, presence of nephrolithiasis, serum calcium, alkaline phosphatase, glomerular filtration rate and parathyroid hormone levels determined at least 12 months prior to referral were evaluated. In patients with [Ca] recorded more than one year earlier, the following four surgical criteria were assessed at the time of that determination: nephrolithiasis, age <50 years, [Ca] >11.4 g/dl and glomerular filtration rate <60 ml/min.

Results: Among the 116 operated patients, 81 (69.8%) had a previous measurement of serum calcium at a time interval ≥12 months. 65 of these 81 patients (56%) had a serum calcium>10.4 g/dl and presented an average delay of 57 months to receive a proper evaluation. Even more, 42 of these 65 patients with hypercalcemia (64.6%) had ≥1 inclusion criteria for surgery. The group of patients that met the surgical criteria were younger, had higher calcium serum values, a greater frequency of nephrolithiasis and a shorter Interval to undergo a parathyroidectomy than those patients who did not meet at least one surgical criterion. Conversely, the 35 patients that were not checked up ≥1 year before the endocrine evaluation was made, were older and had higher calcium serum values that those patients who had normal calcium values evaluated more than one year previously. No differences were found in the presence of kidney stones, surgical criteria or gender between both groups.

Conclusions: In our series of patients with PHPT, the referral to an endocrinologist is performed late, with an average delay of almost 5 years. A significant proportion of these patients have well documented hypercalcemia at least one year before evaluation and more than half of them met criteria for surgery. Despite increased early detection of the disease and avaibility of effective treatment, PHPT continues to be underdiagnosed and undertreated, with increased morbidity. System-level interventions that include proper management of hypercalcemia could improve outcomes.