Purpose: Arterial stiffness is an important predictor of cardiovascular events. A polymorphism in the promoter region of il-6 (−174G>C) has been associated with cardiovascular risk. However, the relationship between this polymorphism and arterial stiffness has not been investigated yet.

Methods: Two hundred and forty-five individuals participated in the study (mean age 40.8 ± 0.5 years old, 164 males). RFLP was performed and three genotypes were determined, GG, GC and CC. Arterial stiffness as expressed by wave reflection was studied using a validated system (SphygmoCor^©) that employs high-fidelity arterial tonometry and appropriate computer software for pulse wave analysis. Augmentation index (AIx) was measured as an index of wave reflection. Higher values of augmentation index indicate increased wave reflection and arterial stiffness.

Results: The distribution of genotype was GG/GC/CC: 125/107/13, respectively. After adjustment for age and sex, multinomial logistic regression analysis revealed that GC genotype is associated with higher values of AIx compared to GG homozygocity (22.56% versus19.6%, p<0.1). Moreover, further analysis showed that the presence of C allele (GC or CC genotype) was linked to increased AIx compared to GG genotype (22.37% versus 19.6%, p<0.1), which indicates impaired elastic properties. The values of aortic and peripheral blood pressures did not differ among three groups (p=NS).

Conclusions: In healthy individuals, a polymorphism of the promoter region of interleukin-6 gene is associated with wave reflection and impaired arterial elastic properties. This finding provides evidence of a possible genetic link between the inflammatory cascade, arterial stiffness and the cardiovascular system.