Abstract
AIMS/INTRODUCTION: Peripheral artery disease (PAD) serves as a risk factor for diabetic foot ulcers (DFUs). PAD pathology involves atherosclerosis and impaired immunity. Non-classical monocytes are believed to have an anti-inflammatory role. 1,25-Dihydroxy vitamin D (vitamin D(3) ) is claimed to have immune-modulating and lipid-regulating roles. Vitamin D receptor is expressed on monocytes. We aimed to investigate if circulating non-classical monocytes and vitamin D(3) were implicated in DFUs associated with PAD. MATERIALS AND METHODS: There were two groups of DFU patients: group 1 (n = 40) included patients with first-degree DFUs not associated with PAD, and group 2 (n = 50) included patients with DFU with PAD. The monocyte phenotypes were detected using flow cytometry. Vitamin D(3) was assessed by enzyme-linked immunosorbent assay. RESULTS: DFU patients with PAD showed a significant reduction in the frequency of non-classical monocytes and vitamin D(3) levels, when compared with DFU patients without PAD. The percentage of non-classical monocytes positively correlated with vitamin D(3) level (r = 0.4, P < 0.01) and high-density lipoprotein (r = 0.5, P < 0.001), whereas it was negatively correlated with cholesterol (r = -0.5, P < 0.001). Vitamin D(3) was negatively correlated with triglyceride/high-density lipoprotein (r = -0.4, P < 0.01). Regression analysis showed that a high vitamin D(3) serum level was a protective factor against PAD occurrence. CONCLUSIONS: Non-classical monocytes frequency and vitamin D(3) levels were significantly reduced in DFU patients with PAD. Non-classical monocytes frequency was associated with vitamin D(3) in DFUs patients, and both parameters were linked to lipid profile. Vitamin D(3) upregulation was a risk-reducing factor for PAD occurrence.