Management of Intact Parathyroid Hormone Levels in Dialysis Patients

Target Range and Treatment Thresholds

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (K/DOQI) recommends maintaining intact PTH (iPTH) levels between 150-300 pg/mL (16.5-33.0 pmol/L) for dialysis patients, with treatment initiated when iPTH exceeds 300 pg/mL 1, 2
The target range of 150-300 pg/mL is associated with a lower risk of adynamic bone disease and high-turnover bone disease, and is recommended for both hemodialysis and peritoneal dialysis patients 1, 2, 3
A treatment threshold of iPTH >300 pg/mL requires active vitamin D sterol therapy to reduce PTH to the target range 1, 2, 3

The 150-300 pg/mL target range represents 2-4 times the upper limit of normal to account for PTH resistance in uremic patients, balancing the risks of low-turnover/adynamic bone disease and high-turnover bone disease 1, 2, 3
iPTH levels <150 pg/mL are associated with low-turnover/adynamic bone disease, which impairs the skeleton's ability to buffer calcium and phosphorus loads, leading to vascular calcification 4, 3, 5
iPTH levels >300 pg/mL are associated with high-turnover bone disease (osteitis fibrosa) and progressive secondary hyperparathyroidism 1, 2, 3

When initiating or adjusting vitamin D therapy, calcium and phosphorus levels should be monitored every 2 weeks for 1 month, then monthly, and iPTH levels should be monitored monthly for at least 3 months, then every 3 months once the target is achieved 1, 6, 5
Treatment must be held if corrected calcium >9.5 mg/dL, phosphorus >4.6 mg/dL, or iPTH falls below 150 pg/mL 5, 7
The Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines recommend a practical algorithm for PTH management, including assessing iPTH level, verifying calcium and phosphorus control, and selecting an appropriate vitamin D sterol 1, 2, 3, 4, 5

For hemodialysis patients, intravenous calcitriol is preferred due to its greater effectiveness compared to oral calcitriol 1, 6
For peritoneal dialysis patients, oral calcitriol 0.5-1.0 μg or doxercalciferol 2.5-5.0 μg, 2-3 times weekly, is recommended 1, 6, 7
If hypercalcemia or hyperphosphatemia is present, paricalcitol or doxercalciferol may be considered due to their lower calcemic effects 1, 6

When iPTH levels exceed 500-600 pg/mL, moderate to severe hyperparathyroid bone disease is typical, requiring more aggressive treatment, according to the American Journal of Kidney Diseases guidelines 8
For severe hyperparathyroidism with iPTH >800-1,000 pg/mL, larger doses of vitamin D sterols are generally required, and parathyroidectomy should be considered if hypercalcemia and/or hyperphosphatemia are refractory to medical therapy, as recommended by the American Journal of Kidney Diseases 8

For the specific purpose of cardiovascular disease prevention, the K/DOQI cardiovascular guidelines recommend a slightly narrower target of 150-300 pg/mL, to prevent arterial stiffness, vascular calcification, and cardiac valve calcification 9
The American Journal of Kidney Diseases guidelines suggest that abnormalities in PTH contribute to arterial stiffness, vascular calcification, and cardiac valve calcification, supporting the target range of 150-300 pg/mL for cardiovascular disease prevention 9

Calcium-based phosphate binders should not be used when iPTH is <150 pg/mL on two consecutive measurements, as recommended by the American Journal of Kidney Diseases guidelines 10

iPTH should be measured every 3 months using an intact PTH assay, according to the American Journal of Kidney Diseases guidelines 9