Red cell density is sex and race dependent in the adult
Blumenfeld, N.; Fabry, M.E.; Thysen, B.; Nagel, R.L.
Journal of Laboratory and Clinical Medicine 112(3): 333-338
1988
ISSN/ISBN: 0022-2143 PMID: 3411195 Document Number: 311525
Using a highly sensitivie method for the determination of red cell densities (Percoll-Stractan continuous isopykinic gradients), we find that, in adults, this parameter varied with sex and race. Whites have red cell densities (expressed as mean corpuscular hemoglobin concentration [MCHC]) that are, on the average, 0.7 gm/dl higher than those in blacks (the differences of the means has p < 2 .times. 10-7). White men have, on the average, 0.6 gm/dl higher MCHC than white women (the difference of the means has p < 6 .times. 10-5). We find a strong correlation between all red cell densities and intracellular K+ and a slightly weaker correlation between red cell density and intracellular Na+ + K+. Men have an average intraerthyrocytic K+ that is approximately 4.5 mmol/L of red cells less than that of women among whites as well as blacks (P < 10-5 and p < 9 .times. 10-4, respectively). Blacks have significantly higher plasma ferritin levels than do whites (in addition to the sex difference). Future work will have to dissect the possible causes of these differences, which include the high incidence of deletional .alpha.-thalassemia (-.alpha./.alpha.alpha.) among blacks, menstruation, hormoanl effects, and the red cell transport and volume regulation differences between sexes and races. Whatever the cause of the sex and racial differences reported here, they are bound to affect the pathophysiologic expression of genetic red cell diseases that are particularly sensitive to the MCHC, such as the sickle cell syndromes.