Association of age, sex, and race with body iron stores in adults: Analysis of NHANES III data

Background This study examined age-, sex-, and race- related increases in body iron stores that have been implicated in disease and the relative utility of the serum ferritin versus the percentage of transferrin saturation for population-based estimation of iron status. Methods and Results Serum ferritin levels were examined by age, sex, and race, and values were compared with the percent transferrin saturation in 20,040 individuals >17 years of age from the third National Health and Nutrition Examination Survey (NHANES III) database. Body iron stores reflected by serum ferritin levels rose in the late teens in men and after menopause in women. This rise was more rapid and maximum ferritin levels were greater for blacks than whites and Hispanics of comparable age and sex. The distribution of values for the serum ferritin differed from the percent transferrin saturation. Conclusions Different patterns of iron accumulation exist according to age, sex, and race. Serum ferritin levels reflect graded, population-based differences in body iron stores, but the percentage of transferrin saturation does not. The hypothesis that iron accumulation may contribute to higher morbidity and mortality rates can be tested in clinical trials of calibrated reduction of body iron stores in defined disease settings. (Am Heart J 2000;140:98-104.)