Nerve function and metabolic control in teenage diabetics

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 prevailing 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 less than 0.001) and longer duration of diabetes (P less than 0.01) than the 22 with no abnormalities. Individual peripheral somatic nerve tests almost invariably correlated only with HbA1 (median motor, P less than 0.05; peroneal motor, P less than 0.001; sural sensory, P less than 0.001) or duration of diabetes (median sensory, P less than 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. DIABETES 32:142-147, February 1983.