Hemoglobin levels in African-Americans

Hemoglobin levels in African-AmericansBeutler and West have made a significant contribution in their comparison of hemoglobin levels in African-American patients with those of white patients from an outpatient clinic population by taking into account iron deficiency, the presence of ␣-thalassemia-1 and ␣-thalassemia-2 trait, and serum creatinine levels higher than 123.8 M (1.4 mg/dL). 1 Nevertheless even when individuals with these factors were eliminated from consideration, the African-Americans maintained a slightly lower mean hemoglobin level than did the white patients, and a higher percentage of African-Americans would have been considered anemic when using the criteria of a hemoglobin level of less than 135 g/L (13.5 g/dL) for men and less than 120 g/L (12 g/dL) for women.The authors speculate on other possible genetic factors that could account for the difference in the average hemoglobin levels in the 2 populations.It is not clear from the article, however, whether the authors have taken into consideration the likely possibility of a higher frequency of hypertension and diabetes and therefore treatment with angiotensin-converting enzyme (ACE) inhibitor and angiotensin receptor blockade medications in their African-American patients than would be found in the white patients.I am a hematologist working in a hospital with a high percentage of African-American patients.In the last decade, we have been impressed by the increased number of patients referred to us for mild acquired anemia who have no other reason found after thorough evaluation except treatment with an ACE inhibitor and/or an angiotensin receptor antagonist.That inhibition of the renin-angiotensin system might result in anemia may be inferred from a number of observations. 2ACE inhibitors have been used successfully to ameliorate the erythrocytosis occurring at high altitude and that following renal transplantation. 3,4 In vitro evidence also suggests that angiotensin II may act as a direct growth factor for erythroid progenitor cells. 5Angiotensin receptor antagonists reduced the number of erythroid burst-forming units in peripheral blood cultures from both chronic hemodialysis patients and healthy volunteers. 5 It will be of great interest if Beutler and West can also examine the mean hemoglobin of the 2 groups after patients being treated with ACE inhibitors and angiotensin receptor blockade medications are also eliminated.