Erythrocyte volume and count: a linear relation descriptive of population differences.

In a sample of 215 adult males the mean red cell volume decreases linearly with increasing red cell concentration. The mean corpuscular volume and the red cell count are found uncorrelated with age of subject. Of these subjects 69 are identified as smokers and 114 as nonsmokers. Linear regression analysis shows negative linear relation for the smoking-defined groups, with slopes judged to be no different. When the regression lines are constrained to be parallel the line for smokers is displaced upward by 2.7 fl. No difference is found in mean corpuscular haemoglobin concentration or reticulocyte count. Haematocrit, haemoglobin, mean corpuscular haemoglobin are also reported. Viscosity of blood is greater in smokers. Optical determination of cell volume and area confirms the linear relation of volume and count.