Abstract
In an attempt to investigate the factors influencing the development of diabetic polyneuropathy, nerve conduction velocities were measured in 112 diabetic subjects, and the levels of fasting blood sugar (FBS), 2, 3-diphosphoglycerate (2, 3-DPG), and glycosylated hemoglobins (HbAl, HbAlc) were simultaneously determined. The diabetic subjects were arbitrarily subdivided into three groups according to their HbA1c values. The first group (41 cases, HbAlc 4-6%) was regarded as wellcontrolled. The second group (37 cases, HbAlc 6-8%) and the third group (34 cases, HbAlc more than 8%) were regarded as fairly and poorly controlled, respectively.
A significant inverse correlation was observed between HbAl and 2, 3-DPG in groups 2 and 3 as well as in the total subjects. HbA1 and the motor conduction velocity (MCV) of the peroneal nerve were also inversely correlated in groups 2 and 3 as well as in the total subjects. However, 2, 3-DPG and the peroneal MCV were correlated only in the total subject, not in the subgroups. Also, FBS was correlated only in the total subjects. The severity of polyneuropathy, as determined from the delay in nerve conduction velocity, may thus be related more with HbAlc and 2, 3-DPG and much less with FBS. Because of the high affinity of HbAlc to oxygen, elevation of HbAlc may decrease the capacity for Hb-O2 dissociation in the peripheral blood, and a decrease in 2, 3-DPG may further aggravate the capacity of oxygen release from the hemoglobins to the peripheral tissue. This implies that impairment in oxygenation of the peripheral nerve might be a significant factor influencing the development of diabetic peripheral neuropathy.
