Niinisalo P, Raitakari OT, Kähönen M, et al. - Findings revealed a correlation of IDO activity (indoleamine 2,3-dioxygenase, an intracellular enzyme linked with artery wall inflammation) with obesity as well as with factors associated with non-alcohol-fatty liver (NAFLD) [namely obesity of visceral type, hypertriglyceridemia and C-reactive protein (in females)]. In addition, IDO activity could well-define risk factors for diabetes and atherosclerosis in 6- and 10-year follow-up in men and premenopausal women.

• In previous studies, correlation between IDO activity and early signs of atherosclerosis has been verified particularly in women.

• A 6- and 10-year follow-up (from 2001 to 2007 and 2011) was performed in women (n = 506; age 24–39) and men (n = 421; age 24–39), to determine the link between an estimate of IDO activity and atherosclerotic risk factors associated with NAFLD.

• Correlation of age-adjusted IDO with BMI and waist remained significant, from 2007 to 2011, in females.

• The correlation of age-adjusted IDO with high-density lipoprotein cholesterol was still significant in 2011, among males.

• On adjusting for age and BMI, the association between IDO and obesity was corroborated in women after 10 years (RR = 1.026) and in men after 6 and 10 years (RR = 1.019 and 1.015, respectively).