Polymorphism in the IL6 promoter region is associated with the risk factors and markers of subclinical atherosclerosis in men: The Cardiovascular Risk in Young Finns Study

Objective: Inflammatory factors modify the risk of coronary heart disease. Promoter region genetic polymorphism of inflammatory cytokine interleukin-6 (IL6 - 174 G > C) is associated with the variation of IL-6 production. We investigated whether IL6 - 174 G > C associates with the risk factors of atherosclerosis and carotid artery compliance (CAC) in young subjects. Methods and results: As part of the Cardiovascular Risk in Young Finns Study, we performed carotid artery ultrasound examinations, IL6 - 174 G > C genotyping and coronary heart disease risk factor determination for 2228 subjects aged 24-39 years. In men CAC was higher for IL6 - 174 GG (2.10 +/- 0.65) than for GC (2.00 +/- 0.68) or CC (1.95 +/- 0.63, %/10 mmHg, mean +/- S.D., p = 0.0221). A similar association was observed for HDL cholesterol (GG 1.22 +/- 0.29. GC 1.15 +/- 0.27 and CC 1.14 +/- 0.28 mmol/L, p = 0.0015) and apolipoprotein A1 (apoA1) (GG 1.44 +/- 0.21, GC 1.40 +/- 0.20, CC 1.38 +/- 0.21 mmol/L, p = 0.0118). The opposite genotype effect was present in systolic (GG 127 +/- 13.1, GC 129 +/- 13.1, CC 130 +/- 14.3 mmHg, p = 0.0382) and diastolic blood pressure (GG 73.8 +/- 9.14, GC 75.1 +/- 8.68, CC 75.9 +/- 9.70 mmHg, p = 0.0374). The genetic effect size for these parameters was not significant in women. Conclusions: IL6 - 174 allele G homozygozity associates with beneficial profile of early predictors of atherosclerosis such as high CAC, HDL-C and apoA1 as well as low systolic and diastolic blood pressure in men. (C) 2008 Elsevier Ireland Ltd. All rights reserved.