Association of C-peptide level with peripheral neuropathy in type 2 diabetes: An observational cross-sectional preliminary study.

Backround And Aims: Peripheral neuropathy is the most common microvascular complication of diabetes mellitus. In subjects with type 1 diabetes (T1D) relationship of C-peptide levels and neuropathy has been observed in several studies, however, there are very few studies in type 2 diabetes (T2D) subjects. In this study we aim to assess the association of C-peptide levels with peripheral neuropathy in Indian subjects with T2D.

Method: One hundred patients of T2D were included in this study. Clinical and laboratory parameter was assessed for all participants. The C-peptide level was measured by fluorometric enzyme immunoassay method. Assessment of diabetic peripheral neuropathy was based on diabetic neuropathy symptom score and the diabetic neuropathy examination scores.

Results: Total 100 patients completed the study. Mean age of subjects was 60.03 years and male: female ratio was 1.17. Peripheral neuropathy was detected in 47% of subjects evaluated. Subjects were further divided in to neuropathy group and no-neuropathy group for analysis. Age in neuropathy group was significantly higher than no-neuropathy group [65.62 ± 10.5 vs 55.08 ± 9.41 yrs (p-value <0.0001)] and similarly duration of T2D was significantly higher in neuropathy group [10.11 ± 6.13 vs 4.16 ± 3.7 yrs (p-value <0.0001)]. Importantly mean fasting C-peptide (2.27 ± 0.98 vs 3.12 ± 0.84 ng/ml) and mean post meal C-peptide (4.27 ± 1.34 vs 5.33 ± 0.89 ng/ml) were significantly lower in neuropathy group compared to no-neuropathy group. An association of HbA1c level and neuropathy was statistically not significant (p = 0.793).

Conclusion: Serum C-peptide concentrations are associated with peripheral neuropathy in T2DM patients, independent of the degree of glycemic control.