beta-hydroxy fatty acids are a major component of lipid A moiety of lipopolysaccaride. We aimed to investigate the role of free beta-hydroxy fatty acids on inflammation, as well as to evaluate their e. ects on cytokine release from human blood cells, and whether they exist in plasma of patients with chronic inflammatory diseases with/without insulin resistance. Peripheral venous blood was incubated with beta-hydroxy lauric and beta-hydroxy myristic acids (each 100 ng, 1 mu g, 10 mu g/mL) up to 24 hours. Cytokines were measured from culture media and plasma. Free fatty acids and biochemical parameters were also measured from patients' plasma. Only beta-hydroxy lauric acid significantly stimulated interleukin-6 production at 10 beta/mL compared to control (533.9 +/- 218.1 versus 438.3 +/- 219.6 pg/mL, P < .05). However, free beta-hydroxy lauric and myristic acids were not found in patients' plasma. Therefore, free beta-hydroxy lauric and myristic acids do not seem to have a role on sterile inflammation in chronic inflammatory diseases associated with insulin resistance.