Acute, reversible autonomic nervous system abnormalities in juvenile insulin-dependent diabetes

Abstract

Autonomic nervous function was studied by infrared TV-pupillography in nine insulin-dependent diabetic subjects with 0 to 3 years duration of diabetes, during poor and good metabolic control. During poor control there was no change in the latency time, the maximal contraction velocity or the amplitude of the light response, whereas the redilatation time was prolonged by 28%, from 2.26±0.27 to 2.90±0.58s (mean±SD) (2p=0.012). The pupil size after adaptation to darkness was unchanged, but the light induced pupillary unrest was reduced by 35% from 1.68±0.62 to 1.10±0.36 mm² (2p=0.0037), and the degree of miosis in continuous illumination was reduced by 47% from 0.32±0.13 to 0.17±0.08 (2p=0.0011), during metabolic derangement. The study has thus demonstrated reversible changes in autonomic nervous function, which are related to the diabetic metabolic state and thereby analogous to the previously well established reversible functional changes in the somatic nervous system in early diabetes.