title: C-reactive protein levels and common polymorphisms of the interleukin-1 gene cluster and interleukin-6 gene in patients with coronary heart disease.
abstract: C-reactive protein (CRP) is an inflammatory marker associated with increased cardiovascular risk. Production of CRP is regulated by interleukin (IL)-1beta, IL-1 receptor antagonist and IL-6. In 160 patients with coronary heart disease (CHD) confirmed by angiography, we examined the relationship between CRP level and five polymorphisms in genes coding for these cytokines: IL-1B(-511), IL-1B(+3954), a variable number tandem repeat (VNTR) polymorphism in intron 2 of IL-1RN [IL-1RN(VNTR)], IL-6(-174) and IL-6(-572). CRP values were logarithmically normalized (log-CRP) for statistical calculations. In univariate analysis, carrier status for the IL-1B(+3954)T allele and IL-1RN(VNTR) allele 2 [IL-1RN(VNTR)*2] correlated with higher (P < 0.01) and lower (P < 0.05) log-CRP values, respectively. Among the potential confounding factors analysed, smoking, body mass index, total cholesterol (P < 0.05 for all) and diabetes (P = 0.056) were positively correlated with CRP level. After adjustment for non-genetic covariates, CRP levels remained significantly (P < 0.01) higher in carriers of IL-1B(+3954)T than in non-carriers: mean log-CRP (with 95% confidence interval) was 0.443 (0.311-0.574) for CT or TT genotypes compared with 0.240 (0.107-0.373) for the CC genotype, which corresponded to back-transformed CRP levels of 2.77 and 1.74 mg l(-1), respectively. Adjusted association was also significant for IL-1RN(VNTR)*2 (P < 0.01), with lower CRP levels in the presence of allele 2: the mean log-CRP value was 0.252 (0.115-0.388) for carriers and 0.421 (0.290-0.552) for non-carriers (CRP 1.79 and 2.64 mg l(-1), respectively). When alleles of both polymorphisms were entered into the model simultaneously, the association remained significant for IL-1B(+3954)T (P < 0.05), but not for IL-1RN(VNTR)*2. We conclude that IL-1B(+3954)T is associated with higher CRP levels in patients with CHD, and we found that this association was significant after adjustment for major risk factors. Our data also suggest a possible relationship of IL-1RN(VNTR)*2 with lower CRP levels in the same patients.
authors.affiliation: Latvian Centre of Cardiology, P. Stradins Clinical University Hospital, Riga.
authors.forename: G
authors.initials: G
authors.lastname: Latkovskis
authors.forename: N
authors.initials: N
authors.lastname: Licis
authors.forename: U
authors.initials: U
authors.lastname: Kalnins
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D015415:Biomarkers; D002097:C-Reactive Protein / Q000032:analysis*; D015897:Comorbidity; D003327:Coronary Disease / Q000097:blood / Q000453:epidemiology* / Q000235:genetics; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood / Q000453:epidemiology; D005091:Exons / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000453:epidemiology / Q000235:genetics; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000235:genetics*; D015850:Interleukin-6 / Q000235:genetics*; D007438:Introns / Q000235:genetics; D007844:Latvia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D009765:Obesity / Q000097:blood / Q000453:epidemiology; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics; D012307:Risk Factors; D012795:Sialoglycoproteins / Q000235:genetics*; D012907:Smoking / Q000097:blood / Q000453:epidemiology; D044465:White People / Q000235:genetics
chemical_list: D015415:Biomarkers; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D015850:Interleukin-6; D012795:Sialoglycoproteins; D002097:C-Reactive Protein