WASHINGTON—Patients who have elevated parathyroid hormone (PTH) levels before the onset of end-stage renal disease are more likely to be prescribed active vitamin D and calcimimetic therapy after they initiate hemodialysis (HD), according to study findings presented at the American Society of Nephrology’s Kidney Week 2019 meeting. They also have a higher risk of uncontrolled PTH.

In the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 4 to 6, spanning the years 2009 to 2018, a total of 5683 incident HD patients from 21 countries had a median predialysis PTH of 275 pg/mL. Sixteen percent of patients initiated HD with PTH concentrations exceeding 600 pg/mL.

Among a subset of 2728 patients who remained in DOPPS, the prevalence of PTH higher than 600 pg/mL at 9 to 12 months after HD initiation increased along with predialysis PTH. The prevalence was 29% for those with a predialysis PTH level greater than 600 pg/mL, where it was 15%, 10%, and 7% for those with predialysis PTH levels of 450-600, 300-450 pg/mL, and 150-300 pg/mL, respectively, Eric W. Young MD, MS, of Arbor Research in Michigan and colleagues reported.

Patients starting HD with PTH higher than 600 pg/mL were much more likely than those with lower predialysis PTH to initiate calcimimetic treatment during the early months of HD, with amplified differences in calcimimetic use over the first 12 months of HD. By 1 year, nearly one-quarter of patients with the highest predialysis PTH received calcimimetics.

More than half patients who initiated HD with PTH levels higher than 300 pg/mL were prescribed active vitamin D in the first year of HD, including more than 70% of patients with predialysis PTH exceeding 600 pg/mL.

Despite more aggressive management, the groups with higher predialysis PTH (300-450 pg/mL, 450-600 pg/mL, and more than 600 pg/mL were 2.5%, 7.2%, and 19.0% more likely to experience uncontrolled PTH of more than 600 pg/mL at 9 to 12 months, respectively, compared with patients who had predialysis PTH level of 150-300 pg/mL. The investigators adjusted for age, sex, race, comorbidities, serum phosphorus, albumin, and hemoglobin, body mass index, and catheter use.

“Findings were consistent with the hypothesis that high PTH in the first year of HD are, in part, reflective of suboptimal predialysis SHPT management,” Dr Young’s team concluded. “These findings help inform clinical management and research goals and provide insight into cost drivers for PTH management in HD.”

This study was funded in part by Vifor Pharma.

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Reference

Young EW, Pisoni RL, Robinson BM, et al. PTH levels prior to initiating hemodialysis: Associations with prescription of PTH-lowering therapies and risk of uncontrolled PTH during the first year of hemodialysis. Presented at the American Society of Nephrology’s Kidney Week 2019 meeting held November 5 to 10 in Washington DC. Poster FR-PO128.