J. Park1, K. Doffek1, T. W. Yen1, K. E. Coan1, T. S. Wang1 1Medical College Of Wisconsin,Surgical Oncology,Milwaukee, WI, USA
Introduction: The majority of patients with primary hyperparathyroidism (pHPT) present with asymptomatic disease, as nonspecific presenting signs and symptoms are heterogeneous to normal aging or other diseases. As a result, patients with hypercalcemia may not be appropriately referred for further evaluation/treatment of potential pHPT. The purpose of this study was to determine the prevalence and trends of potentially undiagnosed pHPT at a tertiary care institution.
Methods: This is a retrospective review of de-identified patient data of all patients from a single health system collected within Informatics for Integrating Biology and the Bedside (i2b2) Cohort Discovery Tool between 1/1/15 and 9/30/15. The study cohort was defined as any patient with at least one serum calcium levels >10.2 mg/dL (normal, 8.6-10.2) and PTH level of >30 pg/mL (normal, 16-72) in the study period; labs were not necessarily drawn concurrently. Patients were divided into 4 groups based on the presence or absence of an ICD-9 diagnosis of HPT (pHPT, secondary/tertiary HPT, HPT not otherwise specified, and no diagnosis). The presence of symptoms of pHPT (nephrolithiasis, gastroesophageal reflux disease [GERD] and/or bone-related disease [osteopenia, osteoporosis, or compression fractures]), extent of hypercalcemia and hyperparathyroidism, and referral to Endocrinology or Surgery within the study period were determined and compared between patients with PTH levels between 30-70 and those >70.
Results: Of the 941 patients, 446 (47%) had PTH levels of 30-70 and 495 (53%) had PTH levels >70. Those patients with a PTH >70 were more likely to have a diagnosis of HPT (primary or unspecified) than patients with PTH levels of 30-70 (Table). There was no difference in reported symptoms between the two groups (p=0.521). However, those with a PTH level >70 were more likely to be referred for additional evaluation (262, 53%) than patients with PTH levels of 30-70 (200, 45%; p=0.005). Patients with PTH >70 were also more likely to be referred to Surgery (31% vs. 22%).
Conclusion: Based on the findings of this study, patients with elevated serum calcium levels and PTH levels 30-70 appear to be less frequently referred for evaluation/treatment of potential pHPT than patients with PTH levels >70 pg/mL. Despite the limitations of this de-identified database, this suggests that pHPT may be underdiagnosed and undertreated within the health care system. Further examination of these data and broader dissemination of the diagnosis and symptoms of pHPT to primary care and other providers should be considered.
