Oxidative stress and serum concentrations of vitamin A in septic patients
© BioMed Central Ltd 2007
Published: 19 June 2007
Sepsis, which may be considered systemic inflammatory response syndrome facing an infectious stimulus, is the main cause of mortality in patients in ICUs. As a result of the systemic inflammatory response and of the decrease of the aerobic metabolism in sepsis, oxidative stress occurs. Vitamin A is recognized by the favorable effect that it exerts on the immune response to infections and antioxidant action. The aim of the present study was to assess the association between serum concentrations of retinol, carotenoids and oxidative stress in septic patients in the ICU.
The subjects were to hospitalized adult patients with diagnosis of sepsis in the ICU from Hospital São Vicente de Paulo and from Hospital Universitário Clementino Fraga Filho, UFRJ, Rio de Janeiro State, Brazil, in the period from January to December 2006. The diagnosis of sepsis was based on the definitions of the International Sepsis Definitions Conference. Serum levels of retinol, total carotenoids and C-reactive protein (CRP) were measured. Oxidative stress was assessed through the lipid peroxidation dosage, which was estimated by thiobarbituric acid reactive substance (TBARS) levels. The APACHE II score was assessed. Forty-six patients were studied and divided into two groups: patients with diet (n = 24) and patients without diet (n = 22). The median age was 64.7 ± 19.4. Reduced levels of retinol and carotenoids were found in 65.2% and 73.9% of the sample, respectively. The group with diet had an inadequacy of retinol in 54% and carotenoids in 62.5%. CRP was high in 100% of the patients. The median vitamin A intake was 8,622 IU, the APACHE II score was 16.1 ± 4.68 and TBARS was 4.48 ± 4.49 nmol/ml. No significant difference was found related to retinol levels, TBARS and APACHE II score between the groups (P = 0.33/P = 0.24/P = 0.43). This was found between CRP levels and carotenoids (P = 0.001/P = 0.047). The results bring subsidies for the establishment/revision of the nutritional protocol directed to the group, particularly as regards the intake of vitamin A, aiming at improvement of the prognosis, evolution and survival of these patients.