A 10-yr follow-up study for the detection of peripheral neuropathy in young patients with type 1 diabetes

The main objective of this work was to follow-up the development of diabetic neuropathy (DN) and its severity in patients with type 1 diabetes over 10 yr. Our intention was also to observe risk factor changes and verify which of them influence the development of neuropathy. The other objective was longitudinal study of electrophysiological parameters, focusing on the early diagnosis of DN.

The prospective study comprised of 62 young patients with type 1 diabetes mellitus (DM) aged 13.9 ± 5.89 yr, with diabetes duration of 5.56 ± 5.11 yr, treated with an intensified insulin regimen. All patients underwent a detailed clinical neurological examination, nerve conduction study (NCS) and biothesiometry three times (baseline, after 5 yr, after 10 yr).

During the follow-up there was an increase in DN prevalence from 24.2% to 62.9% (p < 0.001). The proportion of patients with subclinical neuropathy increased from 17.7% to 46.8% (p < 0.001) and patients with clinical neuropathy from 6.5% to 16.1% (p < 0.001). The main contribution factors for rapid growth of the DN prevalence were poor glycaemic control, diabetes duration and patient's age. Regarding the conduction parameters, the most significant changes were observed in sural nerve SNAP amplitude (-5.2 m/s, p < 0.001) and sural nerve conduction velocity (-8.2 uV, p < 0.001). In contrast, the least significant changes were in peroneal nerve CMAP amplitude (-0.65 mV, p = 0.008).

The results of the study demonstrated a progressive increase in the DN prevalence over time, in particular its subclinical stages. The long-term poor glycaemic control was a determining factor in the rapid DN development. The sensory conduction parameters deteriorated faster than the motor parameters. The present study is one of few of those in type 1 DM, which in relation to risk factors assess not only the presence of neuropathy, but also its severity. The results support the necessity of a regular diagnostic search for DN in diabetic children.