The optimal range of serum intact parathyroid hormone for a lower risk of mortality in the incident hemodialysis patients

The serum intact parathyroid hormone (iPTH) is associated with the prognosis of hemodialysis (HD) patients, however, its optimal range for reducing mortality remains inconsistent. We designed a prospective cohort study of 346 incident HD patients to assess the association between different serum iPTH level and mortality. According to the Kidney Disease Outcomes Quality Initiative (K/DOQI) international guidelines (2003), we divided patients into three groups (iPTH < 150 pg/mL, 150–300 pg/mL and >300 pg/mL). During the median follow-up of 58 months, 157 patients (45.38%) died. Multivariate Cox regression analysis showed that iPTH < 150 pg/mL and >300 pg/mL were associated with all-cause and cardiovascular mortality. Then, we performed a sensitivity analysis of patients divided into 6 serum PTH levels groups according to the folds of the K/DOQI target range. Multivariate Cox regression analysis showed that patients with serum iPTH ≥750 pg/mL, 600–749 pg/mL, 450–599 pg/mL had significantly higher risk of all-cause and cardiovascular mortality compared with those with serum iPTH in the range of 150–299 pg/mL. The association between serum iPTH and mortality shows a U-shaped curve. The optimal serum iPTH level which confers the lowest risk of all-cause and cardiovascular mortality could range from 150 pg/mL to 450 pg/mL in this group of incident HD patients.