Erythrocyte sorbitol level as a predictor of the efficacy of epalrestat treatment for diabetic peripheral polyneuropathy

Abstract The relationship between the effect of aldose reductase inhibitors (ARIs) on the activation of the polyol pathway and on diabetic neuropathy has not been fully established. To address this issue, we investigated the effect of epalrestat (150 mg/day), an ARI, on erythrocyte sorbitol levels as an index of polyol activation and on nerve function test results in 43 patients with diabetic peripheral polyneuropathy. After 6 months of epalrestat administration, erythrocyte sorbitol levels did not decrease in patients as a whole. However, a decrease in erythrocyte sorbitol levels during epalrestat administration was significantly correlated with baseline erythrocyte sorbitol levels ( ρ =−.47, P ρ =−.66, P ρ =.53, P