Elevated blood viscosity in alloxan diabetic dogs and experimentally galactosemic dogs

Blood viscosity was investigated in alloxan-diabetic dogs and in dogs made experimentally hyperglycemic by a galactose-rich diet. The diabetics were prospectively assigned to levels of glycemic control ranging from poor to good. After up to 5 years of study, the blood viscosity of hyperglycemic diabetic animals was significantly greater than normal at both high (100 sec-1) and low (0.1 sec-1) shear rates. Blood viscosity at the low shear rate correlated closely with fibrinogen concentration, (r = 0.75; p less than 0.02) but not with HbA1 concentration (r = 0.14) in the diabetics. Galactosemic animals likewise had elevated blood viscosity at the low shear rate, but the correlation of viscosity with fibrinogen concentration in those animals was not statistically significant (r = 0.42). Plasma viscosity tended to be elevated in both diabetes and galactosemia, but not to a statistically significant degree.