Rheological determinants of red blood cell aggregation in diabetic patients in relation to their metabolic control.

Aims: To determine whether increased red blood cell adhesiveness/aggregation in diabetic patients is related to the extent of their metabolic control.
Methods: We measured erythrocyte adhesiveness/aggregation in a group of 85 adult patients with diabetes mellitus by using citrated venous whole blood and a simple slide test. The erythrocyte adhesiveness/aggregation was determined by measuring the size of the spaces that are formed between the aggregated erythrocytes. We divided the patients into those with either low or high erythrocyte adhesiveness/aggregation values.
Results: The erythrocyte adhesiveness/aggregation values of the two groups differed significantly in terms of their fibrinogen concentration, erythrocyte sedimentation rate, high sensitive C-reactive protein (CRP), total cholesterol and triglyceride concentrations. There was no difference between the two groups regarding the concentrations of HbA(1c). Logistic regression was applied to construct a model to predict the belonging of a patient in the low or high erythrocyte adhesiveness/aggregation group. A linear regression was applied to construct a model to predict the erythrocyte adhesiveness/aggregation values. Both models turned out to include gender, age, fibrinogen, triglyceride, retinopathy, coronary artery disease and age and gender interaction. Neither HbA(1c) nor CRP entered the models.
Conclusions: The degree of erythrocyte adhesiveness/aggregation and several variables of the acute-phase response in patients with diabetes mellitus are not directly related to the degree of metabolic control as evaluated by means of HbA(1c) concentration. Diabetic patients might benefit from rheological or anti-inflammatory interventions regardless of their metabolic control.