PTH and Calcium Levels and Mortality in Peritoneal Dialysis Patients

Patients with chronic kidney disease (CKD) and mineral bone disorder (MBD) face a high symptom burden, including fractures, vascular calcification, and cardiovascular disease, as well as increased risk of morbidity and mortality. According to Kosaku Nitta and colleagues, there are few data available on CKD-MBD among patients receiving peritoneal dialysis.

The researchers conducted a data analysis to examine calcium and parathyroid hormone (PTH) control, as well as associations with mortality in patients on peritoneal dialysis. Results of the analysis were reported during a poster session at the American Society of Nephrology Kidney Week 2023 in a poster titled International Variations in Serum PTH and Calcium Levels and Their Mortality Associations in Peritoneal Dialysis Patients: Results From PDOPPS.

Data from eight countries (Australia and New Zealand [A/NZ], Canada, Japan, Thailand, South Korea, the United Kingdom, and the United States) participating in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) 2014-2022 were included in the analysis. Eligible participants had received peritoneal dialysis for at least 3 months. Cox regression adjusted for potential confounders was used to examine the association between baseline PTH and albumin-adjusted calcium (calcium^Alb) and all-cause mortality.

Mean age of the eligible patients ranged from 54.6 years in South Korea to 63.5 years in Japan. PTH was measured at baseline in 12,642 patients, and serum calcium^Alb was measured at baseline in 14,244 patients. Median PTH ranged from 161 pg/mL in Japan to 363 pg/mL in the United States. Mean calcium^Alb ranged from 9.1 mg/dL in South Korea and the United States to 9.8 mg/dL in A/NZ.

The relationship between PTH and mortality was U-shaped, with the lowest risk at PTH 300 to 599 pg/mL. The risk of mortality was nearly 20% higher at serum calcium^Alb 9.6 mg/dL than at 8.4 mg/dL.

“A large proportion of peritoneal dialysis patients in the multinational study have calcium or PTH levels in ranges associated with substantially higher mortality,” the authors said. “These observations point to the need to substantially improve MBD management in peritoneal dialysis to optimize patient outcomes.”

Source: Nitta K, Bieber B, Karaboyas A, et al. International variations in serum PTH and calcium levels and their mortality associations in peritoneal dialysis patients: results from PDOPPS. TH-PO161. Abstract of a poster presented at the American Society of Nephrology Kidney Week 2023; November 2, 2023; Philadelphia, Pennsylvania.