Exploring the Role of Vitamin D2, Parathyroid Hormone, and C-Peptides as Biomarkers in Diabetic Neuropathy Development

Abstract Background: Diabetic neuropathy affects significant individuals worldwide and is considered a chronic complication of diabetes. However, the exact mechanisms underlying the development of diabetic neuropathy are still not fully understood. Objectives: This study investigated the involvement of vitamin D2, PTH, and C-peptide in the onset of diabetic neuropathy. Materials and Methods: This study included 120 diabetic patients and 30 healthy controls. Diabetic patients were divided into group 1 with neuropathy ( N = 80) and group 2 without neuropathy ( N = 40). The following data were incorporated: sex, age, diabetes duration, and BMI. Biochemical evaluations involved HbA1C, C-peptide, PTH, and vitamin D2. Results: The study’s population had a 52.2 ± 13.9 years mean age. Patients had 9.8 years average diabetes duration, were mostly overweight, and were poorly controlled (mean HbA1C = 8.8). Vitamin D2 was insufficient, particularly in diabetics, and C-peptide measures were markedly low. There were differences in the three parameters between diabetes and controls. Potential relationships among the parameters were detected namely, higher HbA1C, elder, lower vitamin D2, besides higher C-peptide and vitamin D2 levels. ROC-curve metrics for vitamin D2, PTH, and C-peptide, revealed varied diagnostic potential. All parameters were unable to distinguish between patients with or without neuropathy from healthy subjects. Conclusion: The study highlights the importance of glycemic control, insulin production, PTH, and vitamin D2 levels in the context of diabetic neuropathy. While these biomarkers show associations with neuropathy risk, their diagnostic potential is still limited. The associations between age, HbA1C levels, PTH, C-peptide levels, and vitamin D2 levels provide valuable insights into potential contributors to neuropathy risk.