Dataset Information

Parathyroid Hormone Concentrations in Maintenance Hemodialysis: Longitudinal Evaluation of Intact and Biointact Assays.

ABSTRACT:

Rationale & objective

Management of chronic kidney disease mineral and bone disorder requires parathyroid hormone (PTH) concentrations. "Biointact" PTH immunoassays detect "whole" PTH (wPTH), whereas "intact" immunoassays measure PTH plus PTH fragments (iPTH). We aimed to determine whether longitudinal changes in PTH concentrations can be evaluated using biointact and intact immunoassays alike.

Study design

Open noninterventional longitudinal cohort study.

Setting & participants

PTH concentrations were measured quarterly up to 5 times in 102 hemodialysis patients.

Predictors & tests compared

Age, sex, phosphate levels, and others as clinical predictors for PTH trend. Tests compared were iPTH immunoassays from Siemens and Roche and wPTH immunoassays from Roche and DiaSorin.

Outcomes

PTH concentration trend; regression equations; test bias.

Analytical approach

Predictive regression-to-the-mean model for PTH slope; Bland-Altman plots, Passing-Bablok regression, and reference change values for test comparisons.

Results

wPTH concentrations were similar with both immunoassays (wPTH-Roche = 11.7 + 0.97 × wPTH-DiaSorin, r = 0.99; mean ± 1.96 SD bias, 8.2 ± 43.3 pg/mL [17.5% ± 40.9%], by Bland-Altman plots). iPTH-Siemens concentrations were higher than iPTH-Roche concentrations (iPTH-Siemens = -5.4 + 1.33 × iPTH-Roche, r = 0.99; mean ± 1.96 SD bias, 84.0 ± 180.2 pg/mL [21.1% ± 29.8%], by Bland-Altman plots). iPTH-Roche and iPTH-Siemens concentrations were 2- and 2.5-fold higher than wPTH concentrations, respectively. Full agreement among all 4 immunoassays in detecting both significant and insignificant changes in PTH concentrations, upward or downward from one quarter to the next, was reached in 87% of consecutive measurements. In a predictive model, baseline PTH concentrations > 199 pg/mL (wPTH-Roche), 204 pg/mL (wPTH-DiaSorin), 386 pg/mL (iPTH-Roche), and 417 pg/mL (iPTH-Siemens) correctly predicted declining PTH concentration trend in 62% to 68% of patients, but age, sex, hemodialysis vintage, and calcium and phosphate levels were no significant predictors.

Limitations

Limited number of immunoassays, only 59 patients attended all quarterly samplings.

Conclusions

wPTH-Roche and wPTH-DiaSorin concentrations were similar, while iPTH was higher than wPTH concentrations. The iPTH-Siemens immunoassay is either higher calibrated or detects more fragments than iPTH-Roche. However, longitudinal PTH concentration changes largely coincided with all tested immunoassays.

SUBMITTER: Berner C

PROVIDER: S-EPMC8178455 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundThe number of patients ⩾65 years who require maintenance hemodialysis (MHD) is increasing. Although reduced bone turnover in older patients receiving hemodialysis, as reflected by lower serum intact parathyroid hormone (iPTH) and phosphate (P) levels, has been reported, focus on the association between abnormal bone metabolism and the risk of death in older patients receiving MHD has been limited.MethodsWe retrospectively examined data from the Beijing Hemodialysis Quality Control and Improvement Center for 1410 older patients who underwent hemodialysis from 1 January 2012 to 31 December 2016. Baseline, time-dependent (TD) Cox proportional hazards models and Kaplan-Meier analyses were used to evaluate the association between the markers of mineral and bone disorder (MBD) [calcium (Ca), P, and iPTH] and survival. The Kidney Disease: Improving Global Outcomes (KDIGO) target ranges were included as reference values.ResultsSerum P levels >2.49 mmol/l increased the risk of all-cause death [hazard ratio (HR): 1.46; 95% confidence interval (CI): 1.04-2.07; p = 0.030] and cardiovascular death (HR: 2.01; 95%CI: 1.21-3.34; p = 0.007); iPTH levels >600 pg/ml increased the risk of cardiovascular death (HR: 1.95; 95%CI: 1.20-3.15; p = 0.007). Baseline results and TD Cox analyses were similar. All three MBD parameters were within the respective target ranges at least once during the follow-up period in 399 (28.3%) patients, and these patients had better survival rates than those who achieved two of the three target ranges (715/1410 patients; 50.7%); those who achieved one or no target range (296/1410; 21.0%) had the lowest survival rate (all-cause death: log-rank chi square = 83.96, p < 0.001; cardiovascular death: log-rank chi square = 47.06, p < 0.001).ConclusionOlder patients undergoing MHD who achieved the KDIGO target levels for any two or three MBD parameters had lower risks of all-cause and cardiovascular death.

Project description:Increases in 25-hydroxyvitamin D concentrations are shown to improve strength in adults; however, data in pediatric populations are scant and equivocal. In this ancillary study of a larger-scale, multi-sited, double-blind, randomized, placebo-controlled vitamin D intervention in US children and adolescents, we examined the associations between changes in vitamin D metabolites and changes in muscle mass, strength, and composition after 12 weeks of vitamin D3 supplementation. Healthy male and female, black and white children and adolescents between the ages of 9 and 13 years from two US states (Georgia 34°N and Indiana 40°N) were enrolled in the study and randomly assigned to receive an oral vitamin D3 dose of 0, 400, 1000, 2000, or 4000 IU/d for 12 weeks between the winter months of 2009 to 2011 (N = 324). Analyses of covariance, partial correlations, and regression analyses of baseline and 12-week changes (post-baseline) in vitamin D metabolites (serum 25(OH)D, 1,25(OH)2 D, intact parathyroid hormone [iPTH]), and outcomes of muscle mass, strength, and composition (total body fat-free soft tissue [FFST], handgrip strength, forearm and calf muscle cross-sectional area [MCSA], muscle density, and intermuscular adipose tissue [IMAT]) were assessed. Serum 25(OH)D and 1,25(OH)2 D, but not iPTH, increased over time, as did fat mass, FFST, forearm and calf MCSA, forearm IMAT, and handgrip strength (p < 0.05). Vitamin D metabolites were not associated with muscle strength at baseline nor after the 12-week intervention. Changes in serum 25(OH)D correlated with decreases in forearm IMAT, whereas changes in serum iPTH predicted increases in forearm and calf MCSA and IMAT (p < 0.05). Overall, increases in 25(OH)D did not influence muscle mass or strength in vitamin D-sufficient children and adolescents; however, the role of iPTH on muscle composition in this population is unknown and warrants further investigation. © 2018 American Society for Bone and Mineral Research.