Low parathyroid hormone level predicts infection-related mortality in incident dialysis patients: a prospective cohort study

Abstract

Background/Aims: Parathyroid hormone (PTH) is an important factor influencing immunologic dysfunction, but the effect of PTH level on infection-related outcomes remains unclear in incident dialysis. Methods: We evaluated a multicenter prospective cohort study of 1,771 incident dialysis patients (1,260 hemodialysis and 511 peritoneal dialysis) in Korea. Patients were divided into three groups based on serum intact PTH (iPTH) level. The primary outcomes were all-cause and infection-related mortality and multivariate Cox regression analysis was performed to evaluate the role of iPTH in all-cause and infection-related mortality. Results: During the follow-up period of 27.3 months, 175 patients (9.9%) died, and infection-related death represented 20% of all-cause mortality. Both all-cause mortality and infection-related mortality rates (p < 0.001 and p = 0.003, by log-rank) were markedly higher in patients with serum iPTH < 1.50 pg/mL than in the other groups. Multivariate Cox regression analysis revealed that patients with serum iPTH < 150 pg/mL remained at higher risk for infection-related mortality than patients in the target range of 150 <= iPTH < 300 pg/mL, after adjusting for confounding variables (hazard ratio [HR], 2.52; 95% confidence interval, 1.06 to 5.99; p = 0.04). The HR of infection-related mortality in patients with serum iPTH < 150 pg/mL was significantly higher in patients with low serum phosphorus, low Ca x P product, low serum alkaline phosphatase and those older than 65 years. Conclusions: Low serum iPTH level is an independent predictor of infection-related mortality in incident dialysis patients.