Hemorheologic analyses of GD and CTR RBCs. For all the studies, blood samples were from 11 healthy CTRs and 9 GD patients. (A) RBC aggregation in control CTR subjects and GD patients (*P < .05). (B) RBCs disaggregation threshold in CTR and GD patients (*P < .05). (C) Blood viscosity (ηb) in CTR and GD patients at different shear rates. A loop protocol was used with shear rate increasing from moderate value to high value (curves 1), and then the shear rate was reduced (curves 2) to the initial value (see “Methods” for details). Difference between the 2 groups during the incrementing phase of the loop (curves 1; *P < .05). Difference between the value obtained during the incrementing phase of the loop protocol (curves 1) and the value obtained during the decreasing phase of the loop protocol (curves 2) in the GD group (^$P < .05; ^$$P < .01; ^$$$P < .001).