The risk of medically uncontrolled secondary hyperparathyroidism depends on parathyroid hormone levels at haemodialysis initiation

Background. Optimal parathyroid hormone (PTH) control during non-dialysis chronic kidney disease (ND-CKD) might decrease the subsequent risk of parathyroid hyperplasia and uncontrolled secondary hyperparathyroidism (SHPT) on dialysis. However, the evidence for recommending PTH targets and therapeutic strategies is weak for ND-CKD. We evaluated the patient characteristics, treatment patterns and PTH control over the first year of haemodialysis (HD) by PTH prior to HD initiation. Methods. We studied 5683 incident HD patients from 21 countries in Dialysis Outcomes and Practice Patterns Study Phases 4-6 (2009-18). We stratified by PTH measured immediately prior to HD initiation and reported the monthly prescription prevalence of active vitamin D and calcimimetics over the first year of HD and risk of PTH >600pg/mL after 9-12months on HD. Results. The 16% of patients with PTH >600pg/mL prior to HD initiation were more likely to be prescribed active vitamin D and calcimimetics during the first year of HD. The prevalence of PTH >600pg/mL 9-12months after start of HD was greater for patients who initiated HD with PTH >600 (29%) versus 150-300 (7%) pg/mL (adjusted risk difference: 19%; 95% confidence interval : 15%, 23%). The patients with sustained PTH >600pg/mL after 9-12months on HD were younger, more likely to be black, and had higher serum phosphorus and estimated glomerular filtration rates at HD initiation. Conclusions. Increased PTH before HD start predicted a higher PTH level 9-12 months later, despite greater use of active vitamin D and calcimimetics. More targeted PTH control during ND-CKD may influence outcomes during HD, raising the need for PTH target guidelines in these patients.

Automated summary

The study found that patients with higher PTH levels before starting hemodialysis were more likely to be prescribed active vitamin D and calcimimetics during the first year of hemodialysis. Additionally, these patients had a higher risk of having PTH levels greater than 600pg/mL 9-12 months after starting hemodialysis.