Sorbitol concentration in the plasma and erythrocytes of diabetic subjects.

Sorbitol content of plasma and red blood cells is increased in diabetic subjects, and it correlates with plasma glucose concentration. Rapid changes in plasma glucose concentration, either during normalization or impairment of glucose homeostasis, are paralleled by equally rapid changes in plasma or erythrocyte sorbitol content. At variance with a recent proposal, it is concluded that the measurement of sorbitol in red cells is not a reliable indicator of either long-term blood glucose levels or sorbitol accumulation in those tissues in which such an accumulation participates in the pathogenesis of degenerative complications.