In this large observational study of 582 ≥65 years old individuals with mild inflammation, the authors found that urinary hepcidin was positively correlated with ferritin and negatively correlated with the soluble transferrin receptor/ferritin index but was not correlated with markers of inflammation, such as IL-6 or CRP. In contrast, lower serum iron was significantly correlated with higher IL-6 and CRP. Despite its limitations (low number of anemic patients, no serum hepcidin, samples frozen for up to 8 years, possible etiologic misclassification of anemia, etc.) this study led to the hypothesis that hepcidin production becomes upregulated only in situations of overt inflammation, whereas mild inflammation can cause hypoferremia and anemia by hepcidin-independent mechanisms (e.g. direct action of inflammatory mediators on ferroportin) and/or that even normal hepcidin levels are sufficient to sustain the anemia once it is initiated. Thus, it is time for the way back from bedside to bench!
– Manuel Muoz