Optimal frequency of parathyroid hormone monitoring in chronic hemodialysis patients

Abstract

Secondary hyperparathyroidism is a common manifestation of chronic kidney disease (CKD). Serum parathyroid hormone (PTH) level is widely used as a marker for hyperparathyroidism. Currently, there is limited data to guide the frequency of PTH monitoring in CKD patients. The present study was undertaken to determine the optimal frequency of monitoring PTH in patients on maintenance hemodialysis. A cohort of 154 patients on maintenance dialysis at a single outpatient hemodialysis center was included in this retrospective study. In Phase I of the study, PTH was measured every 3 months as per Kidney Disease Outcomes Quality Initiative (KDOQI) recommendations. In Phase II, PTH was measured monthly. In both phases, dietary education and optimization of medications including phosphate binders, vitamin D analogues and calcimimetics were implemented using standard protocols Data from the two phases was compared with each other and with their respective national norms. The percentage of patients with PTH in target range of 150 - 300 pg/ml increased significantly from Phase I to Phase II of the study (25.4 - 40.3%, p < 0.01). There was a significant reduction in the percentage of patients with PTH levels > 300 pg/ml in Phase II compared with national averages (37% vs. 47%, p < 0.02). There was no significant difference in calcium and phosphorus levels or their product. There was a significant increase in the usage of calcimimetics and vitamin D analogues. We observed that increasing the frequency of monitoring PTH from quarterly to monthly was associated with a significant increase in the percentage of patients reaching KDOQI target PTH values.