Effectiveness of a dietary intervention program on the disease activity, metabolic profile and oxidative stress in patients with psoriatic arthritis and psoriasis activity: a clinical, randomized, placebo-controlled study

Abstract

Psoriasis (Ps) and psoriatic arthritis (PA) are associated with increased risk of metabolic syndrome (MetS), adiposity and cardiovascular mortality. In all these conditions there is an increase of oxidative stress and inflammation is recognized as one of the mechanisms involved. However, little is known about the influence of diet and micronutrients in these diseases. Objectives: To evaluate the effectiveness of a dietary intervention on disease activity, metabolic profile and oxidative stress in patients with Ps and AP. Patients and methods: We will include 97 patients with Ps and 97 patients with AP, through clinical trial, randomized, placebo-controlled 12-week intervention. Each stage of disease (Ps and PA) will be randomized at a ratio of 1:1:1 into three groups: GD (diet alone), GDS (diet and supplementation of fish oil) and GP (placebo). Patients with liver, lung and kidney diseases are excluded, as were those in nutritional treatment or use of anabolic drugs and consumption of protein supplements, vitamins or antioxidants. The characteristics of the disease and risk factors for MetS, as well as details of concomitant diseases and medications associated will be evaluated by a standard questionnaire. Will be assessed dietary intake, anthropometric data and physical activity. The body composition will be evaluated by absorptiometry total body by dual energy x-ray absorptiometry (DXA, GE-Lunar DPX-MD +). The activity and disease severity will be evaluated using the PASI (Psoriasis Area Severity Index), DAS28-CRP (Disease Activity Score) and HAQ (Health Assessment Questionnaire). In addition, the biochemical evaluation include anti-LDL and anti-LDLoxidada, insulin, apolipoprotein A and B, adiponectin, malondialdehyde and conjugated dienes, oxidative DNA damage and soluble RAGE. Evaluations are made at two points (baseline and 12 weeks). For statistical analysis, will be used mean and standard deviation, Kolmogorov-Smirnov test, Student's t test, Pearson correlation, chi-square or Fisher's exact test and ANOVA. The intention to treat analysis will be used for final data analysis. The value of significance is p <0.05. (AU)