Lower plasma levels of antioxidant vitamins in patients with metabolic syndrome: A case control study

Abstract

Background. Metabolic syndrome (MS) is a coexistence of metabolic risk factors affecting the development of cardiovascular diseases. Reactive oxygen species, which are excessively produced in MS, participate in its pathogenesis. Vitamins A, C and E are an important part of the non-enzymatic antioxidative barrier in humans. Objectives. The aim of the study was to estimate plasma vitamin A, C and E levels and the intake of these vitamins from the diet in patients with MS. Material and Methods. The study included 182 patients with MS, 94 men and 88 women, aged 30-65 years (mean 57.31 ± 8.28 years). The control group was comprised of 91 subjects, 56 men and 35 women, aged 41-65 years (mean 57.75 ± 5.84 years). The MS diagnosis was based on IDF criteria. The determination of the serum level of vitamin A, C and E was performed using the spectrophotometric method. The food intake was assessed by 24-h dietary recall. Results. The mean plasma vitamin A, C and E levels were significantly lower in MS patients than in the controls (p = 0.05). No correlation was found between vitamin A, C and E intake from the diet and their plasma concentrations in MS patients. Plasma vitamin A, C and E deficiency was observed significantly more often in MS patients than in the control group (15.38% vs. 2.19%, 79.12% vs. 8.79% and 60.45% vs. 5.49%, p < 0.0001, respectively). BMI was the one factor significantly affecting the mean value of vitamin A, C and E levels in MS patients. Conclusions. MS patients demonstrated significantly lower plasma levels of vitamin A, C and E compared to the healthy subjects. Lower plasma levels of antioxidant vitamins with their high intake from the diet indicate antioxidant barrier impairment in MS patients.