Nerve Function and Metabolic Control in Teenage Diabetics

Abstract

Peripheral somatic and autonomic nerve function have been studied in 79 teenage (16–19 yr) diabetics and 20 age- and sex-matched normal controls. Almost three-quarters of the diabetics (72%) had abnormal peripheral somatic nerve function tests, and one-third (31%) had abnormal cardiac parasympathetic tests. Both motor and sensory peripheral somatic nerve abnormalities were related to poor prevalling glycemic control (HbA1) and duration of diabetes. Thus, the 27 patients with three or more (maximum six) peripheral nerve abnormalities had significantly higher HbA1 levels (P < 0.001) and longer duration of diabetes (P < 0.01) than the 22 with no abnormalities. Individual peripheral somatic nerve tests almost invariably correlated only with HbA1 (median motor, P < 0.05; peroneal motor, P < 0.001; sural sensory, P < 0.001) or duration of diabetes (median sensory, P < 0.001). Sensory potential amplitude, as well as conduction velocity, was frequently reduced, implying axonal involvement. These findings suggest that abnormal peripheral and autonomic nerve function are common in young insulin-dependent diabetics and that poor metabolic control is a major determinant of the damage.