Hyperviscosity and microproteinuria in central obesity: relevance to cardiovascular risk.

Abstract

To investigate the role of blood rheology changes in the occurrence of glomerular proteinuria in obese patients with central fat distribution. Fifty-nine obese out-patients (31 with central and 28 with peripheral body fat distribution) and 24 healthy subjects. Blood and plasma viscosity (Rotational viscometer CV100 HAAKE), erythrocyte deformability (whole-blood filtration time), fibrinogen (nephelometry), urinary excretion rates of albumin, IgG, transferrin and IgA (nephelometry). Higher blood viscosity (at low and high shear-rates), plasma viscosity, fibrinogen, erythrocyte aggregability and lower erythrocyte deformability were found in patients with central obesity than in patients with peripheral obesity (P < 0.01) and in healthy subjects (P < 0.001). Furthermore an increased urinary excretion rate of albumin (P < 0.001), IgG (P < 0.001), transferrin (P < 0.01) and IgA (P < 0.05) was found in patients with central obesity than in the other two groups. Blood hyperviscosity (at shear-rate 1 s-1 and 1/200 ratio) significantly correlated with the amount of urinary excretion of proteins independently of the other clinical and metabolic variables. The data demonstrated haemorheologic disorders related to pathologic proteinuria in patients with central obesity. The interaction between these two components may increase the risk of widespread cardiovascular disease.