Does vitamin D have any role in the improvement of diabetic peripheral neuropathy in type 1 diabetic patients?

AIM: The aim of this study was to evaluate the relationship between diabetic peripheral neuropathy (DPN) and vitamin D, nerve growth factor (NGF) and oxidative stress markers in patients with type 1 diabetes.

METHODS

Ninety-six patients with type 1 diabetes were included in the study. All patients were evaluated for DPN with Michigan Neuropathy Screening Instrument. Fasting blood glucose, HbA1c, lipid parameters, 25 (OH) D3, NGF, total oxidant status, total antioxidant status and oxidative stress index were measured.

RESULTS

Twenty-six patients (27 %) had DPN (group 1) and 70 patients did not have neuropathy (group 2). When the groups were evaluated with respect to general demographic characteristics, no differences were detected. Mean age, duration of diabetes and retinopathy were found significantly higher in patients who had neuropathy. Glomerular filtration rate levels were significantly lower in the neuropathy group. Between the groups, 25 (OH) vitamin D levels were significantly lower in the neuropathy group, while there were no differences in NGF levels or in oxidative stress markers. Michigan neuropathy examination score was positively correlated with age, and diabetes duration was negatively correlated with 25 (OH) vitamin D levels. In addition, 25 (OH) vitamin D was positively correlated with NGF. In the logistic regression analysis to determine the independent variables that will affect the development of neuropathy, duration of diabetes was detected as the only factor (p = 0.039, OR = 1.071).

CONCLUSION

It seems that the most important risk factor for the development of neuropathy in type 1 diabetic patients is disease duration.