FADS1 and peripheral vascular disease: Because of C 20:4 n-6 role in the inflammatory cascade and ability to induce oxidative stress, AA is a relevant factor in the pathogenesis of cardiovascular and metabolic diseases such as diabetes mellitus, non-alcoholic fatty liver disease, atherosclerosis, peripheral vascular disease, and hypertension EPA (n-3) and AA (n-6) both compete for use of the delta-5-desaturase enzyme to be synthesized.