Endocrine Abstracts

Introduction: In patients with hypercalcaemia, assessment of urinary calcium excretion helps differentiate primary hyperparathyroidism (PHPT) from familial hypocalciuric hypercalcaemia (FHH). International guidelines recommend 24-hour calcium to creatinine clearance ration (CCCR) as the preferred test for this purpose, but other tests like random (or spot) CCCR test, 24-hour urine calcium excretion (UCE), and calcium to creatinine ratio (CR) are frequently used. The aim of this survey is to evaluate the current practice among UK endocrinologists and endocrine surgeons.

Methods: A web-based anonymous cross-sectional survey, consisting of 8 multiple-choice questions was developed using Survey Monkey®. The survey was disseminated to members of Society for Endocrinology (SfE) and British Association of Endocrine and Thyroid Surgeons (BAETS) between 20/11/2025 and 12/12/2025.

Results: 248 responses from 192 endocrinologists (83.9% consultants) and 56 surgeons (98.2% consultants) were received. Respondents worked in both university/ tertiary hospitals (n=128; 51.6%) and district general hospitals (n=114; 46%). Although the most commonly performed urinary calcium excretion test in hypercalcaemic patients is 24-hour UCE (60.1%), for differentiation between PHPT and FHH, the most preferred test was 24-hour CCCR (43.1%), followed by random CCCR (24.6%), 24-hour UCE (14.5%), and CR (8.5%). Of the respondents who had experience or knowledge with using CCCR, most (59.5%) used a cut-off of >0.01 to rule out FHH, while >0.02 cut off was used by 27.7% respondents. Most clinicians (75.9%) used albumin-adjusted calcium for CCCR calculation, and 71.8% respondents considered vitamin D levels on ≥50 nmol/L to be adequate for any type of urinary calcium measurement. Simultaneous urinary sodium measurement is never or rarely performed by most respondents (71.4%).

Conclusion: The survey provides valuable insight into current UK practice. 24-hour and random CCCR are the most commonly used tests to exclude FHH, but overall, the practice varies widely.