Although Does Liver Biopsy Overestimate Liver Iron Concentration?

mortality among subjects 65 and older with hemoglobin levels even in the “normal range,” is intriguing, in other studies2,3 confounding comorbid conditions accounted for most or all of the difference between anemic and nonanemic groups. Furthermore, even if 22% of the population were at risk for early demise because their hemoglobin levels were found to be low, it would remain to be shown that therapy directed at the hemoglobin level would have any effect on survival. In addition, given that high hemoglobin levels also have deleterious effects on function, it is likely that the normal distribution of hemoglobin represents a balance struck by evolutionary forces. Future studies, some of which we hope to be able to perform, may clarify some of these issues. In the meantime, we believe that physicians will have to content themselves with reference standards based on population norms, as we do with most other clinical laboratory measurements.