Kidney Week

Abstract: TH-PO131

Central vs. Peripheral Access Samplings in Patients on Hemodialysis Induce Variations in Parathyroid Hormone Levels

Session Information

• CKD-MBD: Clinical
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

• 502 Bone and Mineral Metabolism: Clinical

Authors

• Schreiber, Simon, Universite Laval Faculte de Medecine, Quebec, Quebec, Canada

Simon Schreiber, MD

• Desmeules, Simon, Universite Laval Faculte de Medecine, Quebec, Quebec, Canada

Simon Desmeules, MD

• Agharazii, Mohsen, Universite Laval Faculte de Medecine, Quebec, Quebec, Canada

Mohsen Agharazii, MD

• Douville, Pierre, Universite Laval Faculte de Medecine, Quebec, Quebec, Canada

Pierre Douville, MD

• Mac-Way, Fabrice, Universite Laval Faculte de Medecine, Quebec, Quebec, Canada

Fabrice Mac-Way, MD

Background

Parathyroid hormone (PTH) levels are routinely measured in dialysis patients, but international guidelines do not specify the optimal site from which PTH should be drawn. Previous findings suggest that centrally drawn PTH may significantly vary from peripherally sampled PTH¹. This study aimed to compare PTH levels drawn from central venous catheters (C-PTH), peripheral veins (P-PTH) and arteriovenous fistula (AVF-PTH) in hemodialysis patients.

Methods

C-PTH, P-PTH and/or AVF-PTH were simultaneously measured in hemodialysis patients at the CHU de Québec (cohort A) and CISSS Chaudières-Appalaches (cohort B) in Canada from January 1^st to February 28^th, 2024. Architect Intact PTH^TM (Abbott, normal range 25 to 115 ng/L) was used in cohort A and IMMULITE Intact PTH^TM (Siemens, normal range 20 to 100 ng/L) in cohort B. Demographic data were collected and mineral biochemistry were measured according to local standard. PTH levels were classified as “on target” according to sampling site if they were between two and nine times the upper limit of normal.

Results

Cohort A included 69 hemodialysis patients (mean age 69 ± 13 years, dialysis vintage 69 ± 13 months, 86% with a central venous catheter). Mean C-PTH, P-PTH and AVF-PTH were respectively 546 ± 309 ng/L, 409 ± 227 ng/L and 533 ± 325 ng/L. Classification of PTH levels being “on target” were different between C-PTH and P-PTH in 29% of patients. Cohort B included 50 hemodialysis patients (mean age 67 ± 13 years, dialysis vintage 50 ± 60 months, 54% with a central venous catheter). Mean C-PTH, P-PTH and AVF-PTH were respectively 357 ± 264 ng/L, 352 ± 236 ng/L and 475 ± 255 ng/L. Similarly to cohort A, “on target” PTH levels were different between C-PTH and P-PTH in 18.3% of patients.

Conclusion

Our results suggest that sites of sampling may influence PTH levels and could impact the treatment of hyperparathyroidism in hemodialysis patient. Standardization of sampling site should therefore be recommended.

1-Vulpio C, et al. Influence of blood sampling site on intact parathyroid hormone concentrations in hemodialysis patients. Clin Chem. 2010;56(3):489-90.

Funding

• Government Support – Non-U.S.