Extensive Clinical Experience in the Investigation and Management of Primary Hyperparathyroidism

Presentation Number: FRI 342
Date of Presentation: April 1st, 2016

Laura J Reid*, Balakumar Muthukrishnan, Andrew Ditchfield, Andrew Brodie and Fraser W Gibb
Edinburgh Centre for Endocrinology & Diabetes, Edinburgh, United Kingdom

Abstract

Background/Aim:  Primary hyperparathyroidism is an increasingly common condition, which is often managed conservatively, particularly in older patients with relatively modest hypercalcemia.  Recent evidence suggests that increased PTH may be associated with higher mortality.  We sought to characterize the diagnostic features and management of patients referred for evaluation of primary hyperparathyroidism in a single endocrine centre.

Methods:  We undertook a retrospective review of the diagnosis and management of all patients with primary hyperparathyroidism attending an endocrine clinic, within a large university teaching hospital, between 2009 and 2013.  Clinical, biochemical and imaging data were extracted from electronic patient records.  Data are median (inter-quartile range).

Results: The majority of patients were women (198/241), presenting at an older age than men (70 [49 – 79] vs. 64 years [52 – 73], p = 0.013).  Median calcium at presentation was 2.75 mM (2.67 – 2.87) and PTH 12.4 pM (9.3 – 18.9).  Neck ultrasound identified the source in 101/142 patients, sestamibi identified a further 12 and CT/SPECT a further 4.  Abdominal imaging in 87 patients revealed nephrolithiasis in 14 (16%). Of 132 assessed, 42.4% had osteoporosis and a further 40.2% osteopenia.  Vitamin D deficiency was present in 30.9% and was associated with significantly higher PTH (14.7 [12.2 – 21.3] vs. 9.7 nM [7.8 – 15.8], p = 0.003) than replete individuals (25.8%).  Vitamin D replacement (18.7%) was not associated with significant change in calcium, in conservatively managed patients.

In total, 42.3% (n = 102) proceeded to surgery:  a significantly younger cohort (62 [50 – 72] vs. 73 years [64 – 80]), with higher calcium (2.81 [2.70 – 2.95] vs. 2.72 mM [2.63 – 2.82]) and PTH (15.9 [10.4 – 22.1] vs 11.6 pM [8.9 – 15.1]); all p < 0.001.  Surgical cure was achieved in 92.1%. At least one neck imaging modality had been positive in patients with persistent disease post-surgery.  25.3% of all patients presented with a calcium >0.25 mM above the upper limit of normal (2.85 mM). Where surgery was not performed, median calcium fell during two years of observation, with a greater fall observed in those with higher calcium at presentation (-0.11 vs. -0.05, p = 0.003). After 2 years of follow up, no patients with initial serum calcium <2.85 mM (n = 93) had risen above this threshold and 10/12 patients, above 2.85 mM at diagnosis, fell below the threshold at 2 years.

Conclusions:  These data provide reassurance that conservative management (including vitamin D replacement) is not associated with a significant risk of worsening hypercalcaemia over a 2-year period.  When complete, our cohort of over 400 patients should provide further information on the prevalence of complications and impact of newer imaging modalities upon adenoma localization and cure rates.  Large prospective databases present an opportunity to optimize care in this common condition.

 

Nothing to Disclose: LJR, BM, AD, AB, FWG