C-peptide is independent associated with diabetic peripheral neuropathy: a community-based study

BACKGROUND: Because the relationship between C-peptide and diabetic peripheral neuropathy (DPN) is controversial, the aim of our study was to evaluate the relationship between C-peptide and DPN in community-based Chinese patients with type 2 diabetes. METHODS: In total, 220 consecutive type 2 diabetic patients treated by our regional medical consortium were enrolled. DPN was assessed by clinical symptoms, signs, and electromyography. RESULTS: Fasting C-peptide, 2-h postprandial C-peptide and ΔC-peptide (i.e., 2-h postprandial C-peptide minus the fasting C-peptide) serum concentrations in the non-DPN group were significantly higher than those in the clinical DPN group (all P ≤ 0.040) and the confirmed DPN group (all P < 0.002). The three C-peptide parameters were independently associated with DPN (all P < 0.05) after adjusting for age, sex, diabetes duration, smoking status, systolic pressure, body mass index, angiotensin-converting enzyme inhibitors/angiotensin receptor blocker use, fasting plasma glucose, HbA1c, triglyceride and estimated glomerular filtration rate. Compared with the ΔC-peptide quartile 1 (reference), patients in quartile 3 (odds ratio [OR], 0.110; 95% confidence interval [CI] 0.026–0.466; P = 0.003) and quartile 4 (OR, 0.012; 95% CI 0.026–0.559; P = 0.007) had a lower risk of DPN after adjusting for the confounders. CONCLUSIONS: C-peptide was negatively associated with DPN in community-based Chinese type 2 diabetic patients in China.