ORLANDO, Fla.—Very high and very low parathyroid hormone (PTH) levels are associated with the highest mortality rates in hemodialysis (HD) patients. However, a patient’s level of risk may be related to whether the patient also has polycystic kidney disease (PKD).
Kamyar Kalantar-Zadeh, MD, PhD, MPH, and colleagues at the University of California-Los Angeles presented their findings at the National Kidney Foundation’s Spring Clinical Meetings. They demonstrated that three-year averaged PTH levels below 150 pg/mL were associated with the highest mortality rates in HD patients with PKD. Among non-PKD HD patients, three-year averaged PTH levels greater than 600 pg/mL were associated with the highest risk of death.
It is not known whether mortality risk factors related to secondary hyperparathyroidism (SHPT) are similar in HD patients with PKD and non-PKD HD patients. The researchers examined a three-year (July 2001-June 2004) cohort of 58,917 HD patients. Patients were followed-up with until June 2006. The team obtained monthly to quarterly measurements of intact PTH levels over the entire three years and calculated three-year averaged PTH values.
The PKD patients had a mean age of 58.2 years; 49% were female and 8% were diabetic. The non-PKD patients had a mean age of 61.5 years; 46% were female and 47% were diabetic. In fully adjusted models across four PTH increments (less than 150, 150-300, 301-600, greater than 600 pg/mL), the researchers found that PTH levels in the 150-300 pg/mL range were associated with the greatest survival rates in both PKD and non-PKD patients.
The investigators observed marked differences, however, with both high and low PTH levels between the two populations. PTH levels below 150 pg/mL were associated with the highest mortality rates in PKD patients and levels above 300 pg/mL were associated with the highest death risk in non-PKD patients.