Summary:
Introduction: Diabetic neuropathy (DN) is a common complication of type 1
diabetes mellitus (T1DM) in adulthood, whereas it is rare as a clinical problem
during childhood. DN seems to have a multifactorial aetiology, not fully
clarified yet. The role of glutamic acid decarboxylase (GADΑ) and islet
antigen-2 (IA-2Α) autoantibodies in the development of DN remains
controversial.
Aims: The assessment of the prevalence of impaired early indices of DN in T1DM
children and adolescents and the investigation of possible correlations with
different parameters, such as metabolic control, T1DM duration and the presence
of GADA and IA-2A.
Materials and methods: The study population consisted of 129 T1DM patients aged
>8 years, with a disease duration of >2 years and 129 healthy control subjects.
A complete neurological examination was conducted in every subject and
vibration sensation threshold (VST) in the upper and lower extremities was
recorded. Nerve conduction studies (NCS) were performed in T1DM patients for
the examination of median, peroneal and sural nerves. Additionally, metabolic
control (HbA1c) and GADA and IA-2A levels were assessed.
Results: Patients had significantly elevated VST values in the upper and lower
limbs compared to controls, whereas 34.1% of the patients had abnormal NCS. The
presence of GADA and IA-2A was recorded in 62.7% and 58.7% of the patients
respectively. VST or NCS abnormality did not correlate with T1DM duration or
metabolic control. However, patients with positive GADA or IA-2A had lower
compound nerve action potential (CNAP) in the sensory peroneal nerve (p=0.046
and p=0.002, respectively), indicative of axonal dysfunction. Additionally, a
progressive reduction in peroneal action potentials (both sensory and motor)
was observed in parallel with the increase of the number of positive
autoantibodies.
Conclusions: Subclinical DN is frequent among T1DM children and adolescents,
irrespectively of the quality of metabolic control or disease duration. The
association of the presence of GADA and IA-2A autoantibodies with indices of
early axonal dysfunction in T1DM children and adolescents is reported for the
first time.
Keywords:
Diabetes mellitus, Neuropathy, Children, Autoantibodies, Nerve conduction studies
