Objective: Interleukin-1B (IL1B) modulates C-reactive protein (CRP) expression. However, whether IL1B genetic variation is associated with CRP level is unknown. Further, obesity, a state of low-grade inflammation that influences cellular IL-1 functions may modify this association. Methods and results: Study participants (N = 3289), 48% blacks and 52% whites, had CRP level measurements at year 7 and year 15 examinations as part of the CARDIA study. Ten tag single nucleotide polymorphisms (SNPs) that characterize common IL1B gene variation were genotyped. In SNP analysis, no significant associations with either level or change in time CRP were observed after multiple testing adjustments. However, global ILIB gene variation was associated with year 7 to year 15 change in CRP (global nominal p = 0.004, multiple testing corrected p = 0.048) among obese blacks. Compared to the commonest haplotype, a common haplotype that includes the SNP rs1143642 was associated with greater increases in CRP from year 7 to year 15 among obese blacks and whites while another common haplotype that includes the SNP rs3917356 was associated with decreased change in CRP from year 7 to year 15 among obese blacks. The rare alleles of ILIB SNPs, SNP 7114 (rs1143642) and SNP 3298 (rs3917356), were associated with greater increases and decreases in CRP from year 7 to year 15 among blacks, respectively, compared to their common variants. Conclusion: IL1B genetic variation may have a role in CRP level regulation and this association may be modified by obesity.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Feb 2009|
Bibliographical noteFunding Information:
This study was conducted as part of IGAP (Inflammation Genomics and Atherosclerosis Prevention), an ancillary study to CARDIA. The study was supported by the following grants from NHLBI; Cardiovascular Training Grant (1-T32-HL07902), CARDIA (N01 HC95095), IGAP (R01 HL071017) and SeattleSNPs (U01 HL66682 and U01 HL66642); additional assistance was provided by NIEHS grant P30ES07033.
Copyright 2009 Elsevier B.V., All rights reserved.
- Genetic variation
- Plasma C-reactive protein
- Young adults