Enhanced erythrocyte aggregation in type 2 diabetes with late complications

We investigated whether erythrocyte aggregation (EA) is enhanced in type 2 diabetic patients who have developed microvascular or macrovascular complic ations. EA rates at high and low shear rates were analysed in 141 patients with type 2 diabetes who were further divided into 4 subgroups according to the status of diabetic complications and degree of metabolic control. Grou ps II (n = 43) and 2 (n = 23) consisted of well-controlled patients without and with clinically evident late complications, while groups 3 (n = 33) an d 4 (n = 42) represented poorly controlled patients without and with these complications, respectively. 124 healthy subjects served as the control gro up. Mean EA rate was comparable between control subjects and group 1 both a t high (2.05 +/- 0.03 vs. 2.14 +/- 0.07, respectively) and low (6.96 +/- 0. 02 vs. 7.04 +/- 0.06, respectively) shear rates. Mean EA rate was also comp arable between groups 2 and 4 at high (2.76 +/- 0.09 vs. 2.94 +/- 0.07, res pectively) and low (8.18 +/- 0.13 vs. 8.41 +/- 0.1, respectively) shear rat es. However, EA at both shear rates in groups 2 and 4 were significantly hi gher than control subjects, group 1 (p < 0.0001) and group 3 thigh shear ra te EA: 2.76 +/- 0.09 and low shear rate EA: 7.48 +/- 0.07 (p < 0.01). In gr oup 3, EA rates were significantly higher than control subjects and group 1 (p < 0.05) at both shear rates. No significant correlation was found betwe en EA at high and low shear rates and fibrinogen levels in diabetic subgrou ps and control subjects. The data suggest that patients with type 2 diabete s who had developed clinically evident late complications have enhanced EA regardless of the degree of metabolic control. Whether enhanced EA is a pri mary phenomenon contributing to the development of these complications or i t occurs secondary to their development remains to be clarified.