Endocrine Abstracts

Background: Primary hyperparathyroidism (PHPT) is a common cause of hypercalcaemia seen in outpatient endocrinology clinic. Diagnosis is based on biochemistry and exclusion of other conditions, such as familial hypocalciuric hypercalcaemia. Symptomatic patients should usually be referred for parathyroidectomy. For asymptomatic patients there are clear guidelines for surgical referral, based on the Fourth International Workshop (2014) recommendations. This study evaluates current practice for diagnosing and managing primary hyperparathyroidism compared to international guidelines, at a large UK teaching hospital.

Methods: We evaluated all new cases of PHPT seen in outpatient endocrinology clinics between January 2014 and July 2016. Data were collected using a standardised proforma. Data fields included demographics, biochemistry and imaging. Follow-up data on surgical referrals, histology and outcomes were also collected.

Results: Of the 121 patients, at diagnosis, 50.4% were symptomatic. Complete investigation data were available for 117. 59.8% had all relevant investigations performed as recommended per guidelines. Urinary calcium was conducted in 67.5% of patients, of those, 44.3% had inappropriate vitamin D levels at the time of collection. At diagnosis, 30.0% patients had renal complications and 36.3% had osteoporosis. 84% of the 121 met criteria for surgery, although 58.8% were actually referred. The most common reasons for non-referral were patient choice (33.3%) and fitness for surgery (45.5%). On imaging, 74% had a single adenoma, 11.7% had no obvious adenoma. 75% had positive correlation between imaging and surgical findings. 3 months post-operatively, 91% of patients had normal calcium and 68% had normal PTH.

Conclusions: This study shows that the majority of patients with PHPT are diagnosed and investigated as per guidelines. Almost all patients had a normal calcium 3 months post operatively, suggesting surgery was curative. However, urinary calcium estimation was performed without the correction of vitamin D levels in a significant percentage of patients, thereby affecting accuracy of interpretation.