Increased red cell aggregation in diabetes mellitus: association with cardiovascular risk factors.

Red cell aggregation may be higher in diabetic patients and may predispose to cardiovascular disease. Red cell aggregation was measured by a simple photometric method in 122 diabetic patients and 100 matched control subjects, to determine its relationship to cardiovascular risk factors. Red cell aggregation was significantly increased in both Type 1 (4.3 +/- 1.3 vs 3.4 +/- 1.2, p < 0.002) and Type 2 diabetic patients (5.5 +/- 1.5 vs 3.2 +/- 1.3, p < 0.0001). In all diabetic patients aggregation correlated with triglycerides, VLDL, and inversely with HDL and in Type 2 diabetic patients also with body mass index, hypertension, and inversely with duration of diabetes. On multiple regression analysis, triglycerides and body mass index showed an independent association with red cell aggregation and in Type 2 diabetic patients smoking was also associated with increased red cell aggregation. It is concluded that increased red cell aggregation may be one mechanism by which some cardiovascular risk factors could promote cardiovascular disease in diabetes.