Vitamin D status and its association with inflammatory markers among Kurdish type 2 diabetic patients with painful diabetic peripheral neuropathy.

Several clinical studies have shown an association between vitamin D deficiency and painful diabetic peripheral neuropathy (DPN). However, it is still unclear whether vitamin D status and inflammatory markers correlate in patients with painful DPN. In this context, we aimed to investigate the associations between serum vitamin D levels and inflammatory status in Kurdish type 2 diabetes patients (T2DM) with painful DPN and without painful DPN. A clinical case-control study was conducted on 86 Kurdish patients with T2DM. The patients were divided into two groups: the case group consisted of 45 patients with painful DPN and the control group consisted of 41 age- and sex-matched diabetics without DPN. In T2DM patients with and without painful DPN, the prevalence of severe vitamin D deficiency was observed in 46.67% and 21.95% of the patients, respectively (p = 0.0283). The mean serum 25(OH)-vitamin D level in patients with painful DPN (mean = 12.00, SD = 5.78) was significantly lower than in patients without DPN (mean = 16.36, SD = 7.86; p = 0.0041). Regression analysis revealed that vitamin D deficiency (p = 0.0120) and higher glycated hemoglobin (HbA1c) (p = 0.00003) were identified as predictive risk factors for painful DPN. However, there was no significant association between inflammatory status and vitamin D levels. The duration of sun exposure was the only controlling factor for vitamin D in painful DPN patients. In the Kurdish population, lower vitamin D and high HbA1c levels were predictive factors for painful DPN.