Potential Usefulness of Urinary Hepcidin Measurement for Iron Deficiency Anemia in Female Athletes

Hepcidin is a key regulator of iron metabolism and has been proposed as a biomarker for detecting iron deficiency. This study examined serum hepcidin and non-invasively measured urinary hepcidin in 260 female athletes to assess their potential utility in evaluating iron status. Urinary hepcidin/creatinine showed a strong correlation with serum hepcidin and was positively associated with ferritin, suggesting that it reflects underlying iron dynamics. Iron-related measures, including hepcidin, showed expected differences across iron-status categories, consistent with physiological changes from iron repletion to iron deficiency anemia. In diagnostic analyses, both serum hepcidin and urinary hepcidin/creatinine demonstrated good accuracy for identifying iron deficiency including iron deficiency anemia. Serum hepcidin yielded AUCs of approximately 0.85-0.90, while urinary hepcidin/creatinine showed AUCs around 0.85-0.88. Internal validation produced consistent confidence intervals, suggesting stable estimates. At the Youden-optimal cutoff, both markers showed comparable performance, with sensitivities of 0.74-0.91, specificities of 0.73-0.92, and high negative predictive values (0.83-0.97). These cutoff values were derived from internally validated analyses and should be considered preliminary, requiring external validation before broader clinical implementation. These findings suggest that hepcidin-based measures may assist in ruling out iron deficiency or guiding triage decisions. Because urinary hepcidin can be obtained non-invasively and demonstrated performance similar to serum hepcidin, it may represent a practical screening option in athletic populations, although further external validation is needed.