Combined effect of C-reactive protein gene SNP +2147 A/G and interleukin-6 receptor gene SNP rs2229238 C/T on anthropometric characteristics among school children in Taiwan

Abstract

The purpose of this study was to explore the combined effect of the C-reactive protein (CRP) +2147 A/G (rs1205) and interleukin (IL)-6R rs2229238 C/T single-nucleotide polymorphisms (SNPs) on the anthropometric variables of school children in Taiwan. Cross-sectional analyses were performed using the data from the Taipei Children Heart Study-II. After multi-stage sampling, we selected 430 boys and 463 girls with an average age of 13.1 years. We genotyped these individuals for the CRP +2147 A/G and IL-6R rs2229238 C/T SNPs using a TaqMan 5' nuclease assay. Anthropometric characteristics, which included body height, body weight (BW), body mass index (BMI), waist circumference (WC), hip circumference (HC), body fat percentage (BF), and waist circumference to height ratio (WHtR), were measured/calculated. When considering the CRP +2147 A/G polymorphism, GG genotype boys were heavier and had larger BMI, WC, HC, BF and WHtR than A allele carriers. The odds ratio (OR) of larger WHtR in GG genotype boys was 2.14 (95% CI: 1.09-4.21). For the IL-6R rs2229238 C/T polymorphism, T allele carrier girls had larger WC and WHtR than those carrying the CC genotype. The OR of a larger HC for T allele carrier boys was 2.33 (95% CI: 1.16-4.68). Boys with the GG genotype of CRP +2147 A/G and the CC genotype of IL-6R rs2229238 C/T had higher OR for BW, BMI, WC, HC, BF and WHtR than boys who were carriers of the A allele of CRP +2147 A/G and had the CC genotype of IL-6R rs2229238 C/T (OR range=3.86-8.04, all P<0.05). Boys who carry the GG genotype of CRP +2147 A/G and the CC genotype of IL-6R rs2229238 C/T have a greater risk of having abnormal BW, BMI, WC, HC, BF and WHtR and of developing obesity than individuals who do not have these genotypes.