Increased plasma apolipoprotein B levels and blood hyperviscosity in non-insulin-dependent diabetic patients: role in the occurrence of arterial hypertension.

An association between arterial blood pressure and blood viscosity has been suggested in healthy and in diabetic subjects, and that the hemorheological pattern may be influenced by blood lipid alterations. In diabetic patients a relationship between arterial hypertension and blood lipid changes may therefore be suggested. This study concerns 19 type II diabetics with hyperlipidemia (triglycerides=3.2±1 mmol/l; total cholesterol=6.1±1.2 mmol/l; HDL-cholesterol=0.92±0.27 mmol/l; VLDL=29±5%) (group A), and 19 normolipidemic type II diabetics (triglycerides=1.15±0.5 mmol/l; total cholesterol=5.1±1 mmol/l; HDL-cholesterol =1.25±0.38 mmol/l; VLDL=20±5%) (group B). No differences concerning age, body weight, duration of diabetes and glycemic control were found in hyperlipidemic compared to normolipidemic diabetics. On the contrary, higher systolic and diastolic blood pressure levels were demonstrated in group A (167±14 mmHg and 101±5.2 mmHg, respectively) than in group B (144±15 mmHg, p<0.001 and 87±6.9 mmHg, p<0.001, respectively). An increase of plasma apolipoprotein B level (163±27 mg/dl vs 102±21 mg/dl, p<0.001), of plasma viscosity (1.81±0.08 mPas vs 1.51±0.07 mPas, p<0.001) and of blood viscosity (5.37±0.33 mPas vs 5.07±0.04 mPas, p<0.01, at shear-rate of 90 s-1; 18.4±1 mPas vs 14.1±0.9 mPas, p<0.001 at shear-rate of 2.25 s-1) was found in group A, compared to group B. Moreover several positive correlations (p<0.001) between apolipoprotein B level, plasma and blood viscosity were demonstrated in the hyperlipidemic diabetic patients. These findings suggest that blood changes in diabetes might be involved in the occurrence of blood pressure alterations.