Effect of total parathyroidectomy with autotransplantation on bone mineral density in patients with renal secondary hyperparathyroidism

Objective To investigate the impact of total parathyroidectomy with autotransplantation (tPTx+AT) on bone mineral density and serum soluble Klotho (sKlotho) level in patients with secondary hyperparathyroidism (SHPT). Methods A total of 86 patients undergoing tPTx+AT in the Second Affiliated Hospital of Anhui Medical University from June 2019 to May 2022 were recruited in this study. Their demographic characteristics were collected before surgery, along with serum levels of corrected calcium, phosphorus, intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), fibroblast growth factor 23 (FGF23), and sKlotho before and at 5 d, and 1, 3, 6, 12 and 24 months after surgery. Dual energy X-ray absorptiometry was used to determine the BMD values of the lumbar spine L1-L4 before surgery and at 3, 6, 12 and 24 months after surgery. The changes in BMD and serum FGF23 and sKlotho levels before and after tPTx+AT were observed. Results Surgical treatment was successfully completed in all 86 patients, with their clinical symptoms such as bone pain and skin itching significantly improved postoperatively, and markedly decreased serum calcium, phosphorus, iPTH, ALP and FGF23 levels. The sKlotho level was significantly lower at 5 d postoperatively than that preoperatively, with that at 1 month after surgery increased by approximately 24.5% than the preoperative level, and then the level was in a stable trend. The BMD values at the lumbar spine L1-L4 were increased postoperatively, and reached the highest levels at 12 months postoperatively. Further analyses showed that dialysis vintage, duration of SHPT, and ALP, iPTH and FGF23 levels were negatively correlated with the Z-scores of the lumbar spine L1-L4, while sKlotho level was positively correlated with the Z-scores. Conclusion tPTx+AT can significantly improve the clinical symptoms of SHPT patients, regulate the balance of calcium and phosphorus metabolism, increase sKlotho level and reduce FGF23 level. It is an effective method to improve BMD.