Erythrocyte sialic acid and filterability in type 2 diabetic patients

Abstract

Increased erythrocyte membrane sialic acid was found to adversely affect cell deformability. Therefore, we studied the erythrocyte sialic acid content and hemorheological parameters in well controlled non-insulin dependent type 2 diabetic patients (17 non-obese and 19 obese). Plasma viscosity was more significantly increased in the obese (p < 0.001) than non-obese (p < 0.05) diabetics. Erythrocyte filterability (IFR µl/sec), measured by gravity methods using 5/µm Nucleopore filters, did not show significant differences between non-obese (31.72±3.94) and obese (32.4±5.4) subjects when compared with controls (28.05±5.29). Erythrocyte sialic acid content (µg/10⁹ cells) was lower in the non-obese (12.62±2.41) than obese (14.08±2.73) compared to controls (16.17±1.79). In a subset of obese diabetics with fasting plasma free insulin level > 30 mU/L, erythrocyte sialic acid (15.06±3.4/ug/10 cells) correlated inversely with the erythrocyte filtration rate and positively with insulin levels. Insulin levels, on the other hand, correlated positively (p < 0.001) with systolic blood pressure. These results implicate erythrocyte sialic acid in the erythrocyte rheology of hypertensive, obese, type 2 diabetic patients.