Recommended iPTH Level for Dialysis Patients
The recommended intact parathyroid hormone (iPTH) level for dialysis patients is 150 to 600 pg/mL, with the most strongly supported target range being 150-300 pg/mL. 1
Primary Target Range: 150-300 pg/mL
The National Kidney Foundation's K/DOQI guidelines specifically recommend maintaining iPTH between 150-300 pg/mL (16.5-33.0 pmol/L) for all dialysis patients, including both hemodialysis and peritoneal dialysis. 1
This target represents 2-4 times the upper limit of normal to account for PTH resistance in uremic patients, balancing the competing risks of bone disease. 1, 2
The rationale is that iPTH levels below 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. 1
Conversely, iPTH levels above 300 pg/mL are associated with high-turnover bone disease (osteitis fibrosa) and progressive secondary hyperparathyroidism. 1
Treatment Thresholds
Active vitamin D sterol therapy should be initiated when iPTH exceeds 300 pg/mL to reduce PTH back to the target range. 1
When iPTH levels exceed 500-600 pg/mL, moderate to severe hyperparathyroid bone disease is typical, requiring more aggressive treatment. 3
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. 3, 4
Cardiovascular Disease Prevention
For the specific purpose of cardiovascular disease prevention, the K/DOQI cardiovascular guidelines recommend a slightly narrower target of 150-300 pg/mL. 3
This tighter range is recommended because abnormalities in PTH contribute to arterial stiffness, vascular calcification, and cardiac valve calcification. 3
Critical Caveats
Never target normal PTH levels (<65-100 pg/mL) in dialysis patients, as this causes adynamic bone disease with increased fracture risk. 4
Treatment must be held if corrected calcium exceeds 9.5 mg/dL, phosphorus exceeds 4.6 mg/dL, or iPTH falls below 150 pg/mL. 1
Calcium-based phosphate binders should not be used when iPTH is <150 pg/mL on two consecutive measurements. 3
Monitoring Frequency
iPTH should be measured every 3 months using an intact PTH assay (first-generation immunoradiometric assay). 3
When initiating or adjusting vitamin D therapy, iPTH should be monitored monthly for at least 3 months, then every 3 months once the target is achieved. 1
Evidence Quality Note
While the 150-300 pg/mL target is strongly recommended by guidelines, one study found that 88% of patients achieving this range had low-turnover bone disease on biopsy, suggesting the target may be too low for some patients. 5 However, the guideline recommendation of 150-300 pg/mL remains the standard of care and should be followed in clinical practice. 1