Endocrine Abstracts

Introduction

In primary hyperparathyroidism (PHPT) the chronic overproduction of parathormone (PTH) is mostly due to a solitary adenoma.

Aim

The aim of our study was to examine the relationship between calcium-phosphate metabolism and the volume of the parathyroid adenoma (PTA) in patients with PHPT.

Material and methods

The study included 195 patients with biochemical data of PHPT and solitary PTA, visualized on ultrasound. Patients with secondary hyperparathyroidism, multiple PTA and familial forms of PHPT were not included in the study. Patients’ mean age was 57.9 (± 11.5) and 88.7% were females. Serum calcium, inorganic phosphate, PTH, 25-hydroxyvitamin D, creatinine and alkaline phosphatase (ALP) were measured. Glomerular filtration rate (GFR) was calculated through CKD-EPI equations. In all patients, the PTA was localized and measured by ultrasound. The PTA volume was calculated using the formula of a rotating ellipsoid.

Results

The median PTA volume was 0.49 cm³; IQ range 0.22–1.19. It correlated positively with serum calcium and PTH (r = 0.33; P < 0.001 and r = 0.34; P < 0.001 respectively) and negatively with serum inorganic phosphate (r = –0.32; P < 0.001). A significant inverse relationship was found between the PTA volume and serum 25-hydroxyvitamin D level (r = –0.339; P < 0.001). The PTA volume was significantly related to BMI (r = 0.29; P < 0.001) and ALP (r = 0.17; P = 0.02) whereas there was no significant correlation with patients’ age and GFR (P = 0.52 and P = 0.23 respectively).

Conclusion

In patients with PHPT and a solitary PTA, there is a positive association between PTA volume and the biochemical markers of disease activity.