The Impact of Vitamin D Status on Preoperative Ultrasound Findings and Parathyroidectomy Outcomes in Patients With Primary Hyperparathyroidism

Abstract

Background: An impaired vitamin D status may present with an aggressive phenotype of primary hyperparathyroidism (PHPT). We evaluated the impact of 25-hydroxyvitamin D (25(OH)D3) levels on pre-operative ultrasound findings and outcomes following parathyroidectomy.

Methods: Retrospective analysis of 81 patients who had parathyroidectomy for PHPT from January 2008 to October 2016. Patients were grouped according to their 25(OH)D3 levels (deficient (< 30 nmol/L), insufficient (>= 30 and < 50 nmol/L), sufficient (>= 50 nmol/L)). All patients had preoperative ultrasound scans (USS) and their pre-and post-operative biochemistry results and pathology reports were obtained from the hospital portal system.

Results: Preoperatively, there was no statistically significant difference in parathyroid hormone (PTH) (P = 0.19) and adjusted calcium (P = 0.91) levels in different vitamin D subgroups. Parathyroidectomy led to significant improvement of PTH, adjusted calcium, phosphate, alkaline phosphatase and creatinine levels (P < 0.00001). USS did not show any significant difference in localizing single gland disease (SGD) in vitamin D subgroups (sensitivity 57.1%, 62.5% and 55.8% in deficient, insufficient and sufficient groups respectively) and the chances of finding a negative scan was similar in all groups (about 44.5%). USS could not detect any multiple gland disease (MGD). Inferiorly located glands were more involved especially when 25(OH)D3 levels were in the deficient or insufficient range. Postoperatively, patients had higher adenoma weight in vitamin D deficient and insufficient groups (1.42 1.35 g and 1.11 1.39 g) compared to sufficient group (0.58 0.48 g) for SGD and trend was identical for the combined weight of glands in MGD (1.81 2.79 g; 0.93 0.58 g and 0.59 0.33 g respectively). Regression analysis showed an inverse association of 25(OH)D3 level with adenoma weight for SGD (r = -0.006; P = 0.008) but not when multiple glands were resected (r = -0.0007; P = 0.54).

Conclusions: Vitamin D does not influence biochemical severity of disease in PHPT. USS is a reliable tool for localization in SGD but ineffective for MGD and the sensitivity and specificity of scan results are not affected by vitamin D levels. Hypovitaminosis D leads to higher adenoma weight and an inverse relationship exists between the two for SGD.




J Endocrinol Metab. 2017;7(6):172-177
doi: https://doi.org/10.14740/jem477w