Aims/hypothesis: Abnormal rheological properties of erythrocytes, leucocytes and plasma may have a role in the development of diabetic microangiopathy. We hypothesized that changed haemorrheological variables may already be found in children with onset diabetes.
Methods: Erythrocyte deformation (rheoscope), neutrophil deformation (micropipette), erythrocyte aggregation, blood and plasma viscosity were measured in 15 children with insulin-dependent diabetes mellitus before initiation of insulin treatment and 4 to 6 weeks later, 15 diabetic children treated with insulin for 5 to 8 years, 15 healthy children and 15 healthy adults.
Results: At a low shear stress of 0.6 Pa, erythrocyte deformation was decreased in the diabetic children before (-28%), after 4 to 6 weeks (-22%) and after 5 to 8 years (-17%) of insulin treatment compared with healthy children. More active neutrophils were counted in the untreated diabetic children (9 +/- 6%) than in healthy children (3 +/- 2%). Deformability of passive neutrophils was greatly decreased in the children with onset diabetes and moderately reduced in the diabetic children who were treated with insulin. Neutrophil deformation (r = -0.52) and erythrocyte deformation at 0.6 Pa (r = -0.62) were inversely related to haemoglobin A1c. Haematocrit and blood viscosity were increased in the untreated children and in the children treated with insulin for 5 to 8 years. Plasma viscosity and erythrocyte aggregation were similar in the three groups of children.
Conclusion/interpretation: Decreased erythrocyte deformation at low shear force, increased count of active neutrophils and impaired deformability of passive neutrophils may increase the risk for acute cerebro-vascular complications in children with uncontrolled insulin-dependent diabetes mellitus.