Nerve conduction measures in mild diabetic neuropathy in the Early Diabetes Intervention Trial: the effects of age, sex, type of diabetes, disease duration, and anthropometric factors. Tolrestat Study Group for the Early Diabetes Intervention Trial.

We evaluated nerve conduction measures at baseline from 429 patients enrolled in a multicenter diabetic neuropathy study. We defined neuropathy by using recently proposed recommendations but included only patients who had measurable sural and peroneal responses and quantitative vibration thresholds. Patients with type II diabetes were older than type I patients (54.5 versus 39.1 years), were heavier (body mass index [BMI] of 30.9 versus 25.5 kg/m2, and in general had lower evoked amplitudes. The effects of diabetes type upon nerve conduction measures disappeared when age and BMI were included in regression models. The men had lower amplitudes and conduction velocities and longer latencies than the women. The effect of gender was greatly reduced when height was included in the regression models, but gender continued to be a significant predictor of median sensory amplitude, most conduction velocities, and most latencies in these models. The relationships between nerve conduction measures and age, sex, and anthropometric factors were similar for patients with type II, but not those with type I, diabetes to the relationships reported for normal subjects. This may be a result of greater homogeneity with respect to degree of neuropathy for type II patients than for type I patients. These findings are important in designing and interpreting clinical studies of diabetic neuropathy.