Abstract: Objective To investigate the relationship between the level of serum C-peptide(C-P) and neuropathy in patients with type 2 diabetes mellitus(T2DM).Methods The clinical data of 426 patients with T2DM was retrospectively analyzed. These patients were divided into three groups according to their serum C-P levels. From low to high were C-P(≤ 1.7 μg/L) in 152 cases,C-P2(1.8-2.7 μg/L)in 137 cases,C-P3(≥ 2.8 μg/L) in 137 cases.Results The levels of body mass index(BMI), triglyceride(TG), uric acid(UA) and fasting insulin(FINS) in the group of low C-P were lower than those in high C-P group(P<0.05). The levels of high density lipoprotein cholesterol(HDL-C), course and the incidence of diabetic peripheral neuropathy(DPN) and diabetic cardiac autonomic neuropathy(DCAN) were higher than those in high C-P group. The lower level of C-P, the higher incidence of complications(P<0.05). Serum C-P levels in patients with DPN and DCAN were lower than those of nondiabetic peripheral neuropathy(NDPN) and nondiabetic cardiac autonomic neuropathy(NDCAN) (P<0.05). The level of C-P was positively related to the levels of BMI, TG, UA and FINS (P<0.05), and negatively related to HDL-C, low density lipoprotein cholesterol(LDL-C), fasting plasma glucose(FPG), course, incidence of DPN and DCAN(P<0.05). Logistic regression analysis showed that the course and the low level of C-P were independent risk factors of diabetic neuropathy complications after correction of related factors.Conclusion Serum C-P level is independently associated with peripheral neuropathy and cardiac autonomic neuropathy in T2DM.

Key words: type 2 diabetes mellitus, peripheral neuropathy, cardiac autonomic neuropathy, C-peptide