Purpose: A promoter polymorphism (−174G>C) of interleukin-6 has been linked with increased cardiovascular risk Arterial stiffness is an important predictor of cardiovascular risk. Recent data suggest that acute inflammation leads to an increase of aortic stiffness. The effect of this polymorphism on arterial stiffness has not been defined yet.

Methods: Nineteen healthy adults (mean age 34.7 ± 2.2 years old, 11 men) participated in the study (randomised, double-blind design). Salmonella Typhi vaccine was used as an inflammatory stimulus. RLFPs were performed by standard methods for IL-6 and three genotypes were determined, GG, GC and CC. Pulse wave velocity (CF-PWV) was measured as an index of aortic stiffness using a non-invasive device (Complior^®). Arterial stiffness expressed by wave reflection was studied using a validated system (SphygmoCor^©). Augmentation index (AIx) was measured as an index of wave reflection. Arterial stiffness was assessed before and 8 hours after vaccination as well as in 11 non-vaccinated matched volunteers.

Results: Eight hours after vaccination, the G allele was associated with a more prominent change of pulse wave velocity (for GG and GC, 5.70 to 5.92m/sec, p<0.05, for CC group, p=NS) and a significant decrease in AIx (GG and GC, 18.31% to 12.22%, p<0.05 and CC 23% to 14.7%, p=NS), indicating increased aortic stiffness and decreased wave reflection. There were no changes in the control group.

Conclusions: Acute inflammation results in changes of arterial stiffness to a different degree, depending on interleukin-6 genotype. These findings underscore the genetic significance of IL-6 gene on the pathophysiology of cardiovascular system.