To the Editor,

We discussed the article Parathyroidectomy for Normocalcemic Primary Hyperparathyroidism (nPHPT) is associated with Improved Bone Mineral Density regardless of Postoperative Parathyroid Hormone Levels by Lui et al. [1] in our department journal club. We congratulate the authors on their study on bone mineral density (BMD) changes in Normocalcemic Hyperparathyroidism which is a new kid on the block, even in developing Countries now which are showing increasing trends. In this context Normocalcemic Hyperparathyroidism has been a difficult entity for the endocrine surgeons to understand in terms of the physiology involved, the reset of calcium switch pre- and post-surgery, increased incidence of multi glandular disease, decreased PTH normalization after surgery, seasonal variation and also the reversal of end organ changes [2, 3].

We have few queries which may interest future readers. In the present study, the authors did not include the BMD measurement of distal third of the forearm which in 3 site BMD represent the cortical bone which has been shown to be most affected in PHPT. Do the authors think that this may have altered findings of BMD improvement in this study even though cortical or compact bone changes take considerable time? How do the authors explain the phenomenon of PTH not normalizing in nPHPT however with significant BMD improvement in the HIP? Do the authors advocate adoption of a new algorithm for the management of nPHPT based on their findings such as less imaging, more aggressive surgical approach in the form of BNE and less aggressive follow-up even if PTH does not normalize? Did they use Intra Operative PTH monitoring in their cohort of nPHPT? [4]. If so what was the result and what criteria did they use? Did they find more of oxyphil adenoma or other variants of adenoma in their cohort of nPHPT?

Thanks for comment on these issues

Spandana Jagannath

Sarrah Idrees

Sabaretnam Mayilvaganan