Non-classical monocytes frequency and serum vitamin D levels are linked to diabetic foot ulcer associated with peripheral artery disease.

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 ) 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 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 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 levels, when compared with DFU patients without PAD. The percentage of non-classical monocytes positively correlated with vitamin D 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 was negatively correlated with triglyceride/high-density lipoprotein (r = -0.4, P < 0.01). Regression analysis showed that a high vitamin D serum level was a protective factor against PAD occurrence.

CONCLUSIONS

Non-classical monocytes frequency and vitamin D levels were significantly reduced in DFU patients with PAD. Non-classical monocytes frequency was associated with vitamin D in DFUs patients, and both parameters were linked to lipid profile. Vitamin D upregulation was a risk-reducing factor for PAD occurrence.