2011 Volume 38 Issue 6 Pages 719-726
To estimate the lower limits of mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH), we examined data from 988 samples with C-reactive protein levels of 0.0mg/ dl. Samples were obtained from 400 40-59-year-old Japanese females who consulted our institute for health screening between April 2007 and March 2011. At a serum iron value over 90μg/dl level, the hemoglobin concentration, MCV and MCH were 13.6±0.8 g/dl, 91.3±3.6fl and 30.2±1.4pg, respectively. Compared to those at a serum iron level over 90μg/dl level, the serum iron levels relative to hemoglobin concentration, MCV and MCH significantly decreased to 65-74μg/dl (hemoglobin concentration; 13.0±0.9 g/dl, p=3.3E-05), 65-74μg/dl (MCV; 89.1±6.1fl, p=2.8E-04), 75-84μg/ dl (MCH; 29.5±1.7pg, p=1.4E-04), respectively. At a serum iron level of 35-44μg/dl, hemoglobin concentration, MCV and MCH were 12.0±1.0 g/dl, 83.8±5.7fl and 26.7±2.3pg, respectively. We performed multiple regression analyses of the serum iron levels using hemoglobin concentration and MCV or MCH as explanatory variables. We estimated the serum iron level of the sampling data, which showed serum iron level over 90μg/dl, using two different regression formulae. When the estimated serum iron level was within normal limits and the hemoglobin concentration was 12.0 g/ dl, the lower limits of MCV and MCH were calculated as 88.9fl and 29.0pg, respectively, and when the hemoglobin concentration was 12.8 g/dl, the lower limits of MCV and MCH were calculated as 84.8fl and 27.9pg, respectively. Therefore, we should evaluate a 40-59-year-old female for anemia when MCV ≤ 90fl and/or MCH ≤ 29pg, indicating microcytic anemia.