Peripheral nerve function in relation to quality of metabolic control in diabetes

It has been proposed that increased polyol pathway activity resulting from hyperglycaemia induces neuropathy in diabetic patients. Recently, it has been demonstrated that erythrocyte sorbitol content is a reflection of polyol pathway activity in nerve. In the present study the relationship of erythrocyte sorbitol and glycosylated haemoglobin (HbA1) levels to peripheral nerve functions were investigated in 62 diabetic patients. Peroneal and median motor nerve conduction velocities, H-M intervals of the Hoffmann reflex, thermal discrimination thresholds and vibratory perception thresholds, either singly or in combination, were not significantly correlated with erythrocyte sorbitol or HbA1 levels. These findings show that a single measurement of erythrocyte sorbitol or HbA1 content cannot predict impairment of nerve function in diabetic subjects.