Primary Hyperparathyroidism, vitamin D supplementation and imaging outcomes. Experience from a District General Hospital

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 234-256-Bone & Calcium Metabolism: Clinical Trials & Case Series
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-243
Roshini Kulanthaivelu1, Owen Ingram2, Dennis Baker1, Adrian Thomas1, Sudee Doddi1, Prakash Sinha1 and Abbi Lulsegged*3
1South London Healthcare NHS Trust, Orpington, United Kingdom, 2South London Healthcare NHS Trust, Orpington, 3South London NHS Trust, Bromley, United Kingdom
Primary hyperparathyroidism (HPT) is a common endocrine disorder and affected patients are more likely to have vitamin D deficiency. We analysed all cases of primary hyperparathyroidism that were treated at our institution between the years 2009 – 2012. There were 99 cases. Supplemental vitamin D if the adjusted calcium was not higher than 2.9mmol/L and vitamin D level < 30mcg/L. Serum calcium levels were re-measured no earlier than 4 – 6 weeks later.

The average baseline 25-vitamin D level was 14.69mcg/L or 36.6nmol/L. 75% of patients (72/95) had vitamin D levels less than 20mcg/L, 20% had levels between 20 and 29.9mcg/L and only 4% had levels > 29.9mcg/L. Mean adjusted baseline calcium was 2.73mmol/L (reference range 2.15 – 2.60mmol/L) or 10.92mg/dl.  The dose of vitamin D administered was between 1000 – 4800 units daily (levels increased over the years with greater awareness of vitamin D metabolism and safety). The mean adjusted calcium post vitamin D supplementation was actually lower at 2.67mmol/L (10.68mg/dl).  

HPT has a predilection for affecting bone mineral density at the wrist. Significant improvements in BMD are seen at the hips and spine as early as 6 months after successful surgery. However our data indicates that BMD at the wrist can show a (non-significant) trend towards deterioration which persists for a number of years before showing gains. None of these patients sustained fractures of the wrist. There is very little data on changes in BMD at the wrist post parathyroidectomy.

65% of patients had sesta-MIBI and USS scans that both correlated with each other and with the final surgical outcome. Of the dis-concordant scan there was no significant difference in terms of superiority between USS and sesta-MIBI in localising the offending gland emphasising the utility of both scans.

Vitamin D deficiency in HPT is more common than in normocalcaemic individuals. This maybe due to increased conversion of 25-vitamin D to 1,25 vitamin D by elevated PTH levels. Deficiency is associated with increased fracture rate and higher PTH levels while studies have shown reductions in PTH and bone turnover markers without elevations in serum calcium. Calcium levels did not rise significantly in our cohort of patients and if anything the mean calcium after treatment was lower.

We advocate correction of vitamin D deficiency in HPT regardless of whether the patient has surgery or not as it is safe, has possible direct benefits on bone health not to mention the other pleomorphic effects of vitamin D supplementation.

Nothing to Disclose: RK, OI, DB, AT, SD, PS, AL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm