Differences in the hemoglobin cut-off point for the diagnosis of anemia as a function of race/color

Abstract

Hemoglobin levels vary according to age, gender, different phases of pregnancy, smoking habit, and altitude. In the early 90s, researchers began to notice unexplained differences in hemoglobin levels between whites and blacks in various age groups. Since then, studies began to be published to identify which factors would be responsible for such differences. From a review of the literature, we aimed at exposing relevant aspects that may assist in the understanding of why blacks have lower levels of hemoglobin in relation to whites. The Medline, Lilacs, and Pubmed databases were used for this review. Studies have shown that the levels of hemoglobin in blacks are lower, ranging between 0.5 and 1 g/dL in relation to whites. This difference remains, even controlling for possible confounding factors such as intake and iron nutritional status, socioeconomic status, age, and comorbidities among others. The studies, however, do not come to a conclusion about what raises this difference between races. Therefore, proposing specific cut-off points as a function of race, as some authors suggest, may be precipitated and result in not identifying people with anemia, which is considered a serious public health problem in Brazil.