Changes in bone turnover markers and bone mineral density after radiofrequency ablation for mild primary hyperparathyroidism: a prospective cohort study

Abstract

Background The application of radiofrequency ablation (RFA) is becoming increasingly widespread in the treatment of primary hyperparathyroidism (PHPT). However, the effect of RFA treatment on the skeleton in mild PHPT remains unclear. Therefore, the aim of this study was to investigate the change in bone turnover markers and bone mineral density (BMD) before and 2 years after RFA in patients with mild PHPT. Methods In this open-label, prospective study, 81 patients with mild PHPT including 36 treated with RFA and 45 observed without intervention (OBS), along with 81 age-matched healthy controls, were enrolled from November 2018 to September 2021 at Gansu Provincial Hospital. The main outcome measures were levels of serum calcium, serum intact parathyroid hormone (iPTH), and bone turnover markers, including bone-specific alkaline phosphatase (ALP), C-terminal cross-linking telopeptides of type I collagen (β-CTx), and osteocalcin (OC). BMD (femoral neck and lumbar spine) was measured with dual-energy X-ray absorptiometry, and spine radiographs were obtained for vertebral fracture assessment. Paired and unpaired two-tailed t -tests and Spearman rank correlation coefficient were used for statistical analyses. Results Normalized outcomes for both iPTH and calcium levels were achieved in 32 of 36 (88.9%) patients with mild PHPT treated with RFA. There was a significant treatment effect of RFA on bone turnover biomarkers compared with OBS before the treatment (P=0.04) and at the end of follow-up or (P=0.03). BMD of the lumbar spine increased by 1.8% (P=0.03) and remained stable in the femoral neck (P=0.17) after RFA. However, there was an obvious treatment effect of RFA on BMD compared with OBS (P 0.04). The only compartment with a T-score increase in the RFA group was the lumbar spine in (P<0.001). There was no difference in fracture frequency between groups during the follow-up period. Conclusions RFA can improve serum bone turnover markers in patients with mild PHPT and can be expected to increase BMD in the L1–L4 vertebrae and preserve BMD in the femoral neck. Whether RFA can reduce fracture risk in the long-term is a clinical concern for patients with mild PHPT.