Role of height and glycosylated hemoglobin in abnormal nerve conduction in pediatric patients with type I diabetes mellitus after 4-9 yr of disease

Abstract

Objective: To determine the role of height and glycosylated hemoglobin in abnormal nerve conduction in pediatric patients with insulin-dependent (type I) diabetes mellitus.

Research design and methods: Sixty-six pediatric patients (aged 6.3-18.2 yr) with a duration of diabetes from 4 to 8.5 yr but free of clinical neuropathy were evaluated for abnormal nerve conduction.

Results: Mean HbA1 values for 1 and 2 yr before study were available. Electroneurographic findings were significantly different from control subjects in upper and lower extremities and included all five measured velocities, three sensory latencies, and one amplitude. Stepwise regression analysis identified an adverse effect of height on latency (5 of 6) and of mean HbA1 concentration on decreasing velocity (4 of 5). The data analysis from 52 patients who were restudied and who had a duration of diabetes from 5.3 to 9.6 yr confirmed that all velocity values slowed; one of five values did so significantly. The coefficients associated with mean HbA1 concentration usually increased in both upper- and lower-extremity velocity analyses at the follow-up examination. The change in peroneal motor velocity between the first and last examinations was significantly related to the increasing time interval between examinations.

Conclusions: Prospective evaluation of nerve conduction parameters in pediatric patients with diabetes should include both height (the most significant independent variable in latency analysis) and mean glycemic control (the most consistent variable in velocity analyses) as variables in the assessment of the natural history of evolving peripheral neuropathy.