The Effect of Vitamin D Deficiency on the Size and Weight of Parathyroid Adenoma in Patients with Primary Hyperparathyroidism

Mehmet Emin Piskinpasa^1*, Yalcin Hacioglu²

¹Department of Internal Medicine, Istanbul Training and Research Hospital, Istanbul, Turkey - ²Department of Family Medicine, Istanbul Training and Research Hospital, Istanbul, Turkey

Introduction: To assess the effect of vitamin D deficiency on parathyroid adenoma size and weight in patients with primary hyperparathyroidism (PHPT) as well as the association between preoperative biochemical parameters.

Material and methods: This is a retrospective study including 286 patients (246 females/37 males)  with PHPT who were operated on for a single parathyroid adenoma. Correlation analysis was performed between the size and weight of the parathyroid adenoma on the surgical pathology report with preoperative biochemical parameters. Patients with vitamin D levels < 20 ng/mL were accepted as a group 1, and the patients with vitamin D levels ≥ 20 ng/mL were accepted as a group 2, and the groups were compared in terms of all parameters.

Results: In correlations analysis, there were positive correlations of the adenoma size with calcium and parathormone (PTH) (r = 0.192, p = 0.001; r = 0.334, p < 0.001, respectively) and adenoma weight with calcium and PTH (r = 0.219, p = 0.011; r = 0.510, p < 0.001, respectively) but there were negative correlations between adenoma size and weight with vitamin D levels (r = -0.191, p = 0.003; r = -0,231, p = 0.015, respectively). On the other hand there were no correlations of the size and weight of adenomas with calcium and PTH levels in patients with vitamin D levels ≥ 20 ng/mL. Adenoma size, adenoma weight, and PTH were higher in the patients in group 1 than in group 2. (p = 0.02, p = 0.04 and p = 0.001 respectively).

Conclusion: Vitamin D affects preoperative serum PTH level, adenoma size, and adenoma weight in PHPT. So it may not be correct to predict the size and weight of adenoma with preoperative serum PTH and calcium level without considering vitamin D levels.