#6822 ANALYSIS OF IRON STATUS AND ITS INFLUENCING FACTORS IN INITIAL PERITONEAL DIALYSIS PATIENTS
Authors: Peng Yuhao , Hui Zhong 
Published: June 2023

Abstract

Background and Aims
Iron deficiency (ID) is an important cause of poor response to anemia treatment in dialysis patients. The initial status of iron metabolism in uremic patients when they enter peritoneal dialysis (PD) may affect the strategy of iron therapy. Therefore, we investigated and analyzed the initial iron indicator levels and ID in patients with end-stage renal disease undergoing continuous ambulatory peritoneal dialysis (CAPD), and discussed the possible influencing factors of ID and iron supplementation treatment strategies.

Method
The clinical data of patients who underwent PD for 1–3months in West China Hospital, Sichuan University from January, 2011 to January, 2018 were collected. The clinical data including patients' characteristics, medication (oral iron supplement and erythropoietin), iron indicators [ferritin, serum iron, serum iron saturation (TSAT) and transferrin], hemoglobin (HB), serum albumin (Alb), blood lipids, C-reactive protein and IL-6, β2-microglobulin, electrolytes and other biochemical indicators, as well as PD-related parameters. ID or relative ID was defined as ferritin &lt; = 100 ng/ml or TSAT &lt; = 20%, and absolute ID was defined as ferritin &lt; = 100 ng/ml and TSAT &lt; = 20%. Person correlation and Spearman correlation were used for normal distribution and non-normal distribution measurement data, respectively. Kendall correlation was used for categorical variables. Multivariate linear regression was used to analyze the independent influencing factors of ferritin and transferrin saturation. Binary logistic regression was used to analyze the independent influencing factors of ID.

Results
A total of 633 adult patients with stable condition and complete iron metabolism data were enrolled. The mean age was 45.7±14.0 years (18-91 years). There were 397 males (61.1%) and 100 patients (15.8%) with diabetes. The mean HB level was 95.4±18.4g/L, the ferritin level was 277.9±278.1ng/ml, the TSAT 29.9±12.9%, and the transferrin level 1.89±0.4 g/L. Among them, 487 (76.9%) used oral iron therapy and 412 (65.1%) used erythropoietin. 156 (58.8%) had HB less than 100g/L, and 156 (44.2%) had ID. There were 32.2% patients with ferritin &lt;100 ng/mL and 23.4% patients with TSAT&lt;20%. Among patients who used oral iron therapy, 16.2% had absolute ID and 39.6% relative ID. there was no correlation between ID and diabetes, cardiovascular disease, gender, age, Alb, high-sensitivity CRP, IL-6, most of electrolytes, β2 microglobulin, blood leukocyte count, dialysate serum creatinine ratio at 4 hours, D/P Cr(4h), and there was no correlation between ID and eGFR (p = 0.057). Serum magnesium level (r = -0.414, p&lt;0.001), body surface area (r = -0.112, p = 0.005) and triglyceride (r = -0.086, p = 0.03) were negatively correlated with ID. Transferrin level (r = 0.427, p&lt;0.001) and platelet count (r = 0.169, p&lt;0.001) were positively correlated with ID. Multiple linear regression analysis with serum magnesium, body surface area, triglyceride, platelet count and eGFR input showed that triglyceride (p = 0.001), body surface area (p = 0.05) and platelet count (p = 0.001) were independently correlated with ferritin. With transferrin saturation as the dependent variable, showed that only platelet count (p&lt;0.001) was independently associated with transferrin saturation. Binary logistic regression analysis model (dependent variable being presence of ID = 1) showed that body surface area (β = -1.055, p = 0.042), triglyceride (β = -0.295, p = 0.014), serum magnesium (β = 0.997, p = 0.040) and platelet count (β = -0.006, p = 0.014). p&lt;0.001) were independently associated with ID

Conclusion
ID is common in new PD patients in our hospital, with a ferritin level of less than 100 ng/mL in one-third of patients. Platelet counts were higher in ID patients. People with larger body surface area and higher triglyceride levels may have more iron stores. Our study showed new PD patients should pay attention to iron supplementation before and after PD catheterization. Intravenous iron supplementation should be considered in time for those who still have ID after oral iron supplementation. In addition, increased platelet count may predict the occurrence of ID anemia.