Iron deficiency linked to kidney outcomes in non-dialysis-dependent CKD without anemia
Key takeaways:
- Overall, 27.2% of patients had serum ferritin at or below 100 ng/mL.
- The study also found that 13.1% of patients had transferrin saturation levels at or below 20%.
Iron deficiency may be linked to non-dialysis-dependent chronic kidney disease and mortality in patients without anemia, according to results of a nationwide cohort study.
While iron is a key component of hemoglobin and myoglobin, “iron deficiency is associated with numerous pathophysiological conditions, such as anemia, heart failure and cancer,” researchers Hongxue Yu, Xian Shao and Zhixin Guo, of the Nanfang Hospital division of nephrology in China, wrote with colleagues. “The detection of iron deficiency in CKD patients without anemia requires additional support from clinical evidence. However, existing studies have focused on the impact of iron deficiency in anemic CKD patients, with limited evidence on the consequences of iron deficiency in CKD patients without anemia.”
Researchers conducted the multicenter retrospective study of data for 18,878 adults from 24 hospitals across China using deidentified data from the China Renal Data System from 2000 to 2022. The analysis investigated whether serum ferritin or transferrin saturation levels were associated with CKD progression and all-cause mortality outcomes for patients without anemia.
The total cohort had non-dialysis-dependent CKD; 9,989 patients were included in the kidney outcome analysis and 18,481 patients were included in the all-cause mortality analysis.
Findings showed 27.2% of patients had serum ferritin at or below 100 ng/mL, and 13.1% had transferrin saturation levels at or below 20%. Patients with 20% or lower transferrin saturation had a higher risk of kidney disease progression, as seen in the adjusted hazard ratio (aHR = 1.66; 95% CI, 1.16-2.37). This group also had a higher risk of all-cause mortality (aHR = 2.21; 95% CI, 1.36-3.57) vs. those with higher transferrin saturation.
The researchers confirmed the findings in subgroup analyses but did not find a correlation between serum ferritin levels and CKD progression or the risk of mortality.
“Iron deficiency was prevalent in [non-dialysis-dependent] NDD-CKD patients without anemia, and transferrin saturation could be a modifiable risk factor of CKD progression and all-cause mortality,” the researchers wrote. “It is recommended to include screening for iron biomarkers, particularly TSAT, in the early stage of NDD-CKD to improve the prognosis of patients. Furthermore, well-designed randomized clinical trials are necessary to confirm the impact of timely iron supplementation treatment on renal outcomes and all-cause mortality in CKD patients.”
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