Evaluating peripheral nerve function in asymptomatic patients with type 2 diabetes or latent autoimmune diabetes of adults (LADA): results from nerve conduction studies

AimsTo assess the involvement of peripheral nerve dysfunction in asymptomatic patients with latent autoimmune diabetes of adults (LADA) or type 2 diabetes (T2DM), and compare nerve conduction (NC) parameters between the two groups.MethodsA total of 1635 patients without symptoms and signs relevant to diabetic polyneuropathy (1275 with T2DM and 360 with LADA) were included and were further categorized into 3 groups according to diabetes duration: < 5 years, 5-14 years and ≥ 15 years. All subjects underwent nerve conduction studies. Abnormal NC was defined as the abnormality of NC parameters in two or more anatomical nerves.ResultsIn both LADA and T2DM patients, the proportions of abnormal NC increased significantly with increasing durations (both P for trend < 0.001). Specifically, abnormal NC was present in 18.5%, 38.8% and 66.7% of LADA patients with duration of < 5 years, 5-14 years and ≥ 15 years, respectively. Those numbers were 24.8% (P = 0.152, vs. LADA), 25.3% (P = 0.023, vs. LADA) and 62.8% (P = 0.723, vs. LADA) in T2DM. Regarding NC parameters, T2DM patients had higher composite Z-scores of latency than LADA patients within 5 years of duration (P = 0.001). In patients with duration of 5-14 years, the latency Z-scores were comparable between the two groups (P = 0.164), whereas the Z-scores of amplitude were lower (the lower the worse) in LADA than in T2DM (P = 0.035).ConclusionsPeripheral nerve dysfunction is common in asymptomatic patients with LADA or T2DM. Findings of the study suggest that LADA and T2DM differ in the pattern of peripheral nerve involvement over diabetes duration.