Effects of Parathyroidectomy on Plasma iPTH and (1–84) PTH Levels in Patients with Stage 5 Chronic Kidney Disease

Abstract

Currently, the second-generation intact parathyroid hormone (iPTH) assay is commonly used for measuring PTH levels. The iPTH assay detects both full-length (1-84)PTH and (7-84)PTH fragments, which have antagonistic effects on (1-84)PTH in bones and kidneys. The third-generation PTH assay is specific for (1-84)PTH. This study examined the features of different PTH fragments in stage 5 chronic kidney disease (CKD) and the effects of parathyroidectomy (PTX) on the above markers in severe secondary hyperparathyroidism (SHPT) patients. The cross-sectional study included 262 stage 5 CKD patients and 90 controls. A prospective follow-up study was then conducted in 34 PTX patients. Second- and third-generation assays were used to measure plasma iPTH and (1-84)PTH levels, respectively. Circulating (7-84)PTH levels were calculated by subtracting the (1-84)PTH value from the iPTH value. Different plasma PTH fragments were higher, and (1-84)PTH/iPTH was lower in CKD patients than in controls. Plasma (1-84)PTH and (7-84)PTH concentrations increased as iPTH levels increased, and (7-84)PTH increased more evidently. Plasma iPTH, (1-84)PTH and (7-84)PTH levels were 1530.5 (885.0-2111.5) pg/ml, 683.1 (431.4-1018.0) pg/ml, and 739.3 (452.6-1261.0) pg/ml, respectively, in PTX patients. Plasma iPTH, (1-84)PTH and (7-84)PTH concentrations decreased considerably, and the (1-84)PTH/iPTH ratio increased after PTX (median follow-up interval: 10.9 months). Stage 5 CKD patients had higher plasma levels of different PTH fragments, and lower (1-84)PTH/iPTH ratio. PTX could significantly reverse these abnormalities in severe SHPT patients. The iPTH assay overestimated the function of the parathyroid glands; thus, the third-generation PTH assay is likely better for the management of CKD patients.

Effects of parathyroidectomy on plasma PTH fragments and heart rate variability in stage 5 chronic kidney disease patients

“…In this study, patients with PTX were followed up over three months after the surgery (median follow-up time: 6.50 months). Consistent with the previous findings [ 13 ], elevated circulating adjusted calcium, iPTH, (1-84) PTH, (7-84) PTH levels, and a decreased (1-84) PTH/iPTH ratio was alleviated after PTX in severe SHPT patients. This data showed that an improved SDNN was related with decreased (1-84) PTH and (7-84) PTH levels, while improved SDANN was related with decreased (1-84) PTH levels.…”

“…Exclusion criteria of the patients included [ 13 , 16 ]: (1) undergoing maintenance dialysis between 0 and 3 months; (2) persistent SHPT patients who underwent PTX before enrollment and required the second PTX due to residual hyper-functional parathyroid tissue; (3) had a history of kidney transplantation; (4) a fasting blood glucose on the day of evaluation ≥200 mg/dL; (5) the presence of fever, infection or pregnant women; (6) severe congenital heart disease, atrial fibrillation or flutter, high-grade atrioventricular block, permanent pacemaker implantation; (7) severe hepatic disease, chronic obstructive lung disease, malignant tumors, or severe mental disorders; (8) episodes of acute myocardial infarction, stroke, or a major surgical procedure within the past two months; and (9) the use of immunosuppressive drugs, calcitonin, or bisphosphonates.…”

“…In 354 of the CKD5 patients, 208 had severe SHPT and received total PTX with forearm auto-transplantation. The surgical indications were the same as the references [ 13 , 16 , 17 ]. Successful PTX is defined as blood iPTH levels < 50 pg/mL within one week after surgery [ 18 ].…”

“…Circulating PTH levels are currently measured using the second generation intact PTH (iPTH) assays that detect different PTH fragments, including full-length (1-84) PTH and long C-PTH fragments, primarily (7-84) PTH [ 13 ]. The latter has been demonstrated to have antagonistic effects against (1-84) PTH for the bones and kidneys [ 14 ].…”

Raloxifene in the Treatment of Osteoporosis in Postmenopausal Women with End-Stage Renal Disease: A Systematic Review and Meta-Analysis

“…The risk of hip and/or vertebral fractures was further increased in postmenopausal women with the deterioration of kidney function [16,17]. The mainstays of therapy for CKD-MBD include dietary phosphorus restriction, phosphate binders, dialysis, calcimimetics with calcitriol or vitamin D analogs, and parathyroidectomy, which aim to restore the balance between calcium, parathyroid hormone (PTH), phosphorus and vitamin D [18,19].…”