Determinants of plasma Fatty Acid abnormalities in patients with active inflammatory bowel disease: a multivariate analysis.

: Patients with active inflammatory bowel disease (IBD) have increased levels of n3 and decreased levels of n6 plasma long-chain polyunsaturated fatty acids (LC-PUFA). Using multivariate statistical techniques, this study assessed the influence of the potentially important factors of diagnosis (ulcerative colitis versus Crohn's disease), disease activity, malnutrition, location of disease, therapy, age, and sex on these plasma fatty acid abnormalities. Plasma fatty acids were analyzed by semicapillary column gas-liquid chromatography in 73 patients with IBD and 107 healthy controls. The effect of each confounder upon either "low" (below the first quartile of the control group) or "high" (above the third quartile of the control group) levels of each fatty acid (FA) was assessed by means of stepwise logistic regression analyses. After controlling for these factors, disease activity remained the primary factor associated with changes in the plasma FA profile. Moderate/severe activity was significantly associated with low n6 LC-PUFA and was inversely related to high n3 LC-PUFA. Corticosteroid therapy was independently associated with high C16:0 and C18:2n6 plasma values and low C20:3n6 values and unsaturation index. Sulfasalazine therapy was inversely associated with low percentages of both C18:0 and C20:3n6. Hypoalbuminemia was significantly related only to low values of C18:0. No relationship between any confounder and high levels of n3 LC-PUFA was found. The observed relationships may be of importance in the pathogenesis and treatment of IBD.