The association of iron status on clinical outcomes in peritoneal dialysis: a retrospective study over 10 years

Iron deficiency and overload are common in kidney disease. Although the relation between iron status and clinical outcome is well reported in hemodialysis, there are few publications in peritoneal dialysis (PD). We investigated the association between iron status and outcomes of new PD patients. We reviewed 1,804 new adult PD patients between 2011 and 2020. Their baseline status was classified into reference iron status (RIS), absolute iron deficiency (AID), low iron storage (LIS), functional iron deficiency (FID), and high iron status (HIS) according to the transferrin saturation and serum ferritin level. After a median follow-up of 35.2 months, outcome measures, including patient survival, technique survival, peritonitis-free survival, number of hospital admission, and length of hospitalization, were analyzed. FID and HIS were found in 18.8% and 57.5% patients, respectively. The 2-year patient survival for RIS, AID, LIS, FID, and HIS groups were 87.4%, 90.2%, 94.7%, 82.0%, and 83.5%, respectively (log-rank test, <i>p</i> < 0.001). However, all-cause mortality rate was not significantly different between iron status groups after adjusting for clinical confounders. The FID group was associated with more hospital admission than the other groups, but the difference became insignificant after adjusting for clinical confounders. In conclusion, FID and HIS are common in incident PD patients. FID was associated with a trend of lower patient survival and higher hospitalization rate, but the differenced were not significant with multi-variable analysis. Further studies are required to determine the desirable iron saturation or ferritin level to guide iron replacement therapy.