Increased mean red cell volume in diabetes mellitus.

We investigated the relationship between fasting plasma glucose (FPG) and mean red cell volume (MCV) in 103 diabetic patients. Patients were selected among those admitted to our Diabetic Clinic according to the following criteria: absence of anemia, polycytemia, liver disease and use of drugs other than antidiabetic agents. All patients had peripheral blood profile performed on admission on a fasting venous sample for MCV and FPG. A highly significant correlation (r = 0.336; p less than 0.0005) was found between MCV and FPG in individual patients and when analyzed as a whole group. Patients were then divided into two subgroups according to FPG, using the value of 200 mg/dl as an arbitrary limit. The correlation between MCV and FPG remained significant, though weak (r = 0.243; 0.10 greater than p greater than 0.05) only in the subgroup with FPG greater than 200 mg/dl (n = 36). Therefore our data suggest a relationship between FPG and MCV in diabetic patients with FPG exceeding 200 mg/dl. The nature of this relation is only a matter of speculation.