Scope: Chronic venous disease (CVD) is a common pathology which involves both genetic susceptibility and environmental factors and has an increased socio-economic impact in the advanced stage when varico-se veins are present. Obesity represents the main risk factor for CVD and, with the ageing of global popu-lation, the prevalence of both disease are projected to substantially increase, hence, the term ‘phlebesity’. Vi-tamin D deficiency is frequent in the elderly, especially in the presence of obesity. Aim: The purpose of the present study was to investigate the effects of calcitriol, (1,25(OH)2-D3), the active form of vitamin D on the oxidative stress in the varicose veins harvested from obese and non-obese patients subjected to superficial vein surgery (cryostripping method).

Methods: Patients were randomized into 2 groups, obese (n=12) and non-obese (n=17). Venous samples were treated or not with 1,25(OH)2-D3 (100 nM, 12 hours incubation) and used for hydrogen peroxide (H2O2) measurement by means of a spectrophotome-tric method, FOX (Ferous Iron Xylenol Orange) assay.

Results: Vitamin D deficiency was diagnosed in obese vs non-obese patients that were indirectly correlated with the amount of H2O2 generated by the vascular samples. Ex vivo incubation of the varicose veins ex-plants with calcitriol significantly reduced the amount of reactive oxygen species in both obese and non-obese patients.

Conclusions: In obese patients with CVD, plasma level of vitamin D inversely correlates with the amount of hydrogen peroxide generated by the varicose explants. Ex vivo acute treatment with the active form of vitamin D mitigated the oxidative stress in the venous walls. Research supported by the university grant PIII-C5-PCFI-2017/2018-01.