Application of nonparametric methods of planning multifactorial analysis in the study of the dose-dependent effect of polyunsaturated fatty acid intake on fatty acids in erythrocyte in patients with atopic dermatitis

Atopic dermatitis (AD) is one of the most common chronic skin diseases, which is a serious medical and social problem and requires an integrated approach to treatment and prevention due to its high prevalence and tendency to progressive course in most patients. <b>The aim</b> of the study was to analyze the dose-dependent effect of polyunsaturated fatty acids (PUFA) consumption on erythrocyte fatty acid composition in AD patients using nonparametric multifactorial analysis. <b>Material and methods</b>. The study included 65 patients (aged 18 to 59 years) with AD of varying severity (28 moderate and 37 severe). For 30 days, patients received ω-3 PUFAs in addition to the main diet: 19 patients - with 3.6 g of fish oil (200 mg of eicosapentaenoic acid and 240 mg of docosahexaenoic acid), 46 patients - with 0.72 g of fish oil. Erythrocyte fatty acids were determined by gas chromatography with flame-ionisation detection (GC-FID). There were used nonparametric methods of multifactor planning. The main methods of this study were: the Kruskal-Wallace criterion (H-criterion), as well as the Fisher z-transformation of dependent variables. <b>Results</b>. Significant differences in the content of some fatty acids in erythrocytes were revealed between the groups. In the group with the 2:1 ratio, a statistically significant decrease in the content of saturated (6:0, 8:0, 10:0, 20:0, 22:0, 24:0), monounsaturated fatty acids (15:1 10-cis, 16:1 9-cis, 17:0, 17:1, 18:1 trans, 22:1 13-cis), ω-3 PUFA (18:3 ω-3 all cis 9,12,15) and elaidic acid (18:2 9-cis, 12-trans) was noted compared to the 10:1 group. In the 2:1 group, there was an increase in the content of 20:1 11-cis and 22:6 ω-3 all cis 4,7,10,13,16,19. Three-way analysis of the data showed significant changes in the fatty acid profile depending on the severity of AD, mainly in patients with a severe course, characterized by both a decrease (15:1 10-cis, 16:1 9-cis, 17:1, 18:2 9-cis, 12 trans, 18:3 ω-3, 22:6 ω-3) and an increase (8:0, 10:0, 17:0, 22:1 13-cis) of certain fatty acids. In women with AD, a decrease in the level of short-chain saturated fatty acids (6:0, 8:0, 10:0) was found. <b>Conclusion</b>. The obtained results indicate that PUFA intake positively affects the lipid profile of red blood cells in patients with AD. The identified changes may be associated with a potential impact on the course of the disease, but further studies, including an assessment of the AD clinical manifestations and long-term observations, are needed to confirm this hypothesis.