title: Hematologic differences between African-Americans and whites: the roles of iron deficiency and alpha-thalassemia on hemoglobin levels and mean corpuscular volume.
abstract: The average results of some laboratory measurements, including the hemoglobin, mean corpuscular volume (MCV), serum transferrin saturation (TS), serum ferritin, and white blood cell count of African-Americans differ from those of whites. Anonymized samples and laboratory data from 1491 African-American and 31 005 white subjects, approximately equally divided between men and women, were analyzed. The hematocrit, hemoglobin, MCV, TS, and white blood cell counts of African-Americans were lower than those of whites; serum ferritin levels were higher. When iron-deficient patients were eliminated from consideration the differences in hematocrit, hemoglobin, and MCV among women were slightly less. The -3.7-kilobase alpha-thalassemia deletion accounted for about one third of the difference in the hemoglobin levels of African-Americans and whites and neither sickle trait nor elevated creatinine levels had an effect. Among all subjects, 19.8% of African-American women would have been classified as "anemic" compared with 5.3% of whites. Among men, the figures were 17.7% and 7.6%. Without iron-deficient or thalassemic subjects, the difference had narrowed to 6.1% and 2.77% and to 4.29% and 3.6%, respectively. Physicians need to take into account that the same reference standards for hemoglobin, hematocrit, MCV, and TS and the white blood cell count do not apply to all ethnic groups.
authors.affiliation: The Scripps Research Institute, Department of Molecular and Experimental Medicine, 10550 North Torrey Pines Rd, La Jolla, CA 92037, USA. beutler@scripps.edu
authors.forename: Ernest
authors.initials: E
authors.lastname: Beutler
authors.forename: Carol
authors.initials: C
authors.lastname: West
mesh_terms: D044383:Black People / Q000235:genetics; D016022:Case-Control Studies; D004909:Erythrocyte Indices; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006447:Hemoglobin H / Q000235:genetics; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000097:blood; D000090463:Iron Deficiencies; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D017384:Sequence Deletion; D012805:Sickle Cell Trait / Q000097:blood / Q000235:genetics; D044465:White People / Q000235:genetics; D017085:alpha-Thalassemia / Q000097:blood* / Q000235:genetics; D001741:Black or African American
chemical_list: D006454:Hemoglobins; D006447:Hemoglobin H; D007501:Iron