Relationship between erythrocyte sorbitol content and diabetic microangiopathy in patients with non-insulin-dependent diabetes mellitus: the study of a diet loading test

To determine whether erythrocyte sorbitol content could become an indicator of diabetic microangiopathy, we studied the relationship between the changes in erythrocyte sorbitol content in response to diet loading and diabetic microangiopathy in patients with non-insulin-dependent diabetes mellitus. The increase of change in erythrocyte sorbitol content (ΔSor) after diet loading (420 kcal) significantly correlated with that of plasma glucose levels (ΔBS). The patients with ≤40 m/s of motor or sensory nerve conduction velocity (MCV and SCV) had significantly higher ΔSor ΔBS values than those with > 40 m/s of MCV and SCV; nevertheless, there were no significant differences in ΔBS between the two groups. Furthermore there was a significant negative correlation between nerve conduction velocity and ΔSor and ΔSor ΔBS values. On the other hand, the patients with nephropathy or retinopathy showed no significant increase in ΔSor or ΔSor ΔBS compared with patients without these complications. The results demonstrated that ΔSor and ΔSor ΔBS could become indicators of the presence or severity of diabetic neuropathy. Furthermore the more significant participation of alteration in the polyol pathway in the pathogenesis of neuropathy than of the other microangiopathies was suggested.