Low levels of ficolin-3 are associated with diabetic peripheral neuropathy

Aims Ficolin-3, a soluble molecule of the innate immune system, has a primary role in the activation of the lectin pathway in the complement system. Considering that inflammatory mechanisms are involved in complement activation and take part in the pathophysiology of diabetic peripheral neuropathy (DPN), we conducted this study to explore the link between serum ficolin-3 and DPN in diabetic patients. Methods A total of 466 diabetic patients were enrolled in this cross-sectional study. DPN was evaluated by neurological symptoms, neurological signs, neurothesiometer and electromyogram. The concentration of serum ficolin-3 was determined by enzyme-linked immunosorbent assay. Results The concentration of serum ficolin-3 was lower in DPN patients compared with non-DPN patients (18.73 ± 4.75 vs. 26.69 ± 5.68 ng/mL, P < 0.001). In addition, it was found negatively correlated to the vibration perception threshold ( r = −0.158; P = 0.025). The results of multiple regression analysis of DPN indicated that age, diabetes duration, serum ficolin-3 were all independent impact factors for DPN ( P < 0.05). Patients were then assigned into quartiles according to the serum ficolin-3 levels, and the prevalence of DPN ascended as the concentration of ficolin-3 descended (Trend analysis, P < 0.001). Compared with ficolin-3 Quartile 1 (referent), the risk of DPN was significantly greater in Quartile 2 (OR 2.76; 95 % CI 1.56–4.88; P < 0.001), Quartile 3 (OR 3.02; 95 % CI 1.69–5.40; P < 0.001) and Quartile 4 (OR 6.84; 95 % CI 3.39–13.80; P < 0.001). Conclusions Lower ficolin-3 level is independently associated with DPN, and it may be a potential biomarker for DPN.