Associations between iron markers with hemoglobin and outcomes in peritoneal dialysis patients: results from the PDTAP study.

BACKGROUND AND HYPOTHESIS

Iron metabolism markers, such as transferrin saturation (TSAT) and ferritin, are crucial in anemia management in patients with CKD and those undergoing dialysis, yet optimal levels remain unelucidated.

METHODS

We conducted a prospective multicenter cohort study using data from the nationwide Peritoneal Dialysis Telemedicine-based Management Platform (PDTAP) to analyze TSAT, ferritin, and hemoglobin (Hb) levels, and their associations with mortality in the peritoneal dialysis (PD) population.

RESULTS

Our study included 4429 PD patients, analyzing data through restricted cubic splines and Cox regression models, adjusted for multiple confounders. Non-linear associations between Hb levels and TSAT/ferritin were observed. Hb levels increased with TSAT up to 40%, then plateaued, whereas ferritin levels increased with the decline of Hb. Further, ferritin levels above 200 ng/mL were independently linked to increased mortality risk [hazard ratio (HR) 1.207, 95% confidence interval (CI) 1.134-1.286], with this effect decreasing as high-sensitivity C-reactive protein levels rose. This risk was notably significant in patients with a history of cardiovascular disease. A ferritin/Hb ratio >2 was associated with increased risk of mortality after adjusting for demographic, nutritional factors and erythropoiesis agents (HR 1.219, 95% CI 1.144-1.299). The ferritin/Hb ratio demonstrated superior predictive ability for iron responsiveness compared with ferritin alone.

CONCLUSION

Serum ferritin level exceeding 200 ng/mL was indepently associated with a higher risk of martality in Chinese PD population. Monitoring the ferritin/Hb ratio may help assess the relative iron content in the body and provide reference for iron supplementation among patients undergoing PD.