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

Immune Response and Lipid Metabolism Gene Polymorphisms Are Associated with the Risk of Obesity in Middle-Aged and Elderly Patients

More than two billion people around the world are overweight or obese. Even in apparently healthy people, obesity has a potent effect on their quality of life. Experimental data indicate the role of infectious agents in systemic inflammation, revealing a correlation between the dietary habits of people with obesity and the level of systemic inflammation mediators, serum lipid concentration, and hormonal and immune status. This study aimed to determine the association of immune response and lipid metabolism gene polymorphisms with the risk of obesity. This study included 560 Caucasian participants living in Western Siberia (Russian Federation). A total of 52 polymorphic sites in 20 genes were analyzed using the 5′ TaqMan nuclease assay. Four risk-associated polymorphic variants were discovered—two variants in immune response genes (IL6R rs2229238, OR = 1.92, 95% CI = 1.36–2.7, p = 0.0002 in the dominant model; IL18 rs1946518, OR = 1.45, 95% CI = 1.03–2.04, p = 0.033 in the over-dominant model) and two variants in lipid metabolism genes (LPA rs10455872, OR = 1.86, 95% CI = 1.07–3.21, p = 0.026 in the log-additive model; LEPR rs1137100, OR = 2.88, 95% CI = 1.52–5.46, p = 0.001 in the recessive model). Thus, polymorphisms in immune response and lipid metabolism genes are potentially associated with the modification of obesity risk in the Caucasian population.

Genetic analysis of hsCRP in American Indians: The Strong Heart Family Study

Background

Increased serum levels of C-reactive protein (CRP), an important component of the innate immune response, are associated with increased risk of cardiovascular disease (CVD). Multiple single nucleotide polymorphisms (SNP) have been identified which are associated with CRP levels, and Mendelian randomization studies have shown a positive association between SNPs increasing CRP expression and risk of colon cancer (but thus far not CVD). The effects of individual genetic variants often interact with the genetic background of a population and hence we sought to resolve the genetic determinants of serum CRP in a number of American Indian populations.

Methods

The Strong Heart Family Study (SHFS) has serum CRP measurements from 2428 tribal members, recruited as large families from three regions of the United States. Microsatellite markers and MetaboChip defined SNP genotypes were incorporated into variance components, decomposition-based linkage and association analyses.

Results

CRP levels exhibited significant heritability (h² = 0.33 ± 0.05, p<1.3 X 10⁻²⁰). A locus on chromosome (chr) 6, near marker D6S281 (approximately at 169.6 Mb, GRCh38/hg38) showed suggestive linkage (LOD = 1.9) to CRP levels. No individual SNPs were found associated with CRP levels after Bonferroni adjustment for multiple testing (threshold <7.77 x 10⁻⁷), however, we found nominal associations, many of which replicate previous findings at the CRP, HNF1A and 7 other loci. In addition, we report association of 46 SNPs located at 7 novel loci on chromosomes 2, 5, 6(2 loci), 9, 10 and 17, with an average of 15.3 Kb between SNPs and all with p-values less than 7.2 X 10⁻⁴.

Conclusion

In agreement with evidence from other populations, these data show CRP serum levels are under considerable genetic influence; and include loci, such as near CRP and other genes, that replicate results from other ethnic groups. These findings also suggest possible novel loci on chr 6 and other chromosomes that warrant further investigation.

Low-grade inflammation markers in children and adolescents: Influence of anthropometric characteristics and CRP and IL6 polymorphisms

Overweight and obesity are associated with chronic and subclinical inflammation due to an imbalance of inflammatory mediators. However, the association with gene polymorphism has been rarely studied in children. The aim of this study was to determine if serum concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) are related to the IL6 rs1800795, IL6 rs2069845 and CRP rs1205 polymorphisms (SNPs) according to body mass index (BMI) in a sample of children and adolescents. A cross-sectional study in 470 students between 7 and 17yearsof age of anthropometric characteristics, high sensitivity-CRP (Hs-CRP) and IL-6 levels and three SNPs genotyped. The prevalence ratio of hs-CRP>3mg/L in obese individuals was 4.15 (CI 2.43-7.06; p=0.01), and it was 1.91 (CI 1.03-3.55; p=0.03) in overweight individuals and 1.74 (CI 1.05-2.88 p=0.03) in females. Individuals with waist circumference (WC) and body fat percentage (BF%) alterations showed elevated levels of hs-CRP (p=4.3×10^-5 and p=5.3×10^-6). The combination of any two anthropometric measurement increases CRP levels, especially combinations with obesity body mass index (BMI): BMI+WC and BMI+BF%. Among the overweight/obesity group, T allele carriers of CRP rs1205 showed lower levels of hs-CRP (0.5, IQR=0.3-1.8mg/L) than CC homozygotes (1.5, IQR=0.4-3.4mg/L, p=0.018). Additionally, considering subjects with two or three anthropometric alterations for CRP rs1205: rs1205 T allele carriers had lower levels of hs-CRP (0.7, IQR=0.3-2.7mg/L) than CC homozygotes (1.2, IQR=0.5-3.5mg/L, p=0.02). In conclusion, carriers of the rs1205/T allele with higher BMIs had lower levels of hs-CRP. Schoolchildren who were overweight/obese had higher levels of CRP and IL-6, whereas individuals with WC and BF% alterations had higher levels of CRP.

Effect of GAS6 and AXL Gene Polymorphisms on Adiposity, Systemic Inflammation, and Insulin Resistance in Adolescents

The present study was designed to explore the effects of GAS6 and AXL gene polymorphisms on adiposity, systemic inflammation, and insulin resistance in adolescents. After multistage sampling from the data of the Taipei Children Heart Study-III, we collected 358 boys and 369 girls with an average age of 13.3 years. We genotyped the adolescents' GAS6 rs8191973, GAS6 rs8191974, AXL rs4802113, and AXL rs2304232 polymorphisms. Significantly higher body mass index (BMI), waist circumference (WC), and hsCRP levels were found in boys with the GG genotype of GAS6 rs8191974 than A allele carriers; higher IL-6 and insulin levels and increased HOMA-IR were found in boys with the GG genotype of AXL rs2304232 than the A allele carriers. There was a significant difference in hsCRP levels of boys with the TT, TC, and CC genotypes of AXL rs4802113. Boys with both the GG genotype of GAS6 rs8191973 and the GG genotype of GAS6 rs8191974 exhibited higher BMI, WC, IL-6, and hsCRP levels than the boys carrying both the C allele of the GAS6 rs8191973 and the A allele of the GAS6 rs8191974. In conclusion, GAS6 and AXL polymorphisms are associated with adiposity, systemic inflammation, and insulin resistance in adolescents, especially in boys.

The role of inflammatory pathway genetic variation on maternal metabolic phenotypes during pregnancy

Background

Since mediators of inflammation are associated with insulin resistance, and the risk of developing diabetes mellitus and gestational diabetes, we hypothesized that genetic variation in members of the inflammatory gene pathway impact glucose levels and related phenotypes in pregnancy. We evaluated this hypothesis by testing for association between genetic variants in 31 inflammatory pathway genes in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort, a large multiethnic multicenter study designed to address the impact of glycemia less than overt diabetes on pregnancy outcome.

Results

Fasting, 1-hour, and 2-hour glucose, fasting and 1-hour C-peptide, and HbA1c levels were measured in blood samples obtained from HAPO participants during an oral glucose tolerance test at 24-32 weeks gestation. We tested for association between 458 SNPs mapping to 31 genes in the inflammatory pathway and metabolic phenotypes in 3836 European ancestry and 1713 Thai pregnant women. The strongest evidence for association was observed with TNF alpha and HbA1c (rs1052248; 0.04% increase per allele C; p-value = 4.4×10⁻⁵), RETN and fasting plasma glucose (rs1423096; 0.7 mg/dl decrease per allele A; p-value = 1.1×10⁻⁴), IL8 and 1 hr plasma glucose (rs2886920; 2.6 mg/dl decrease per allele T; p-value = 1.3×10⁻⁴), ADIPOR2 and fasting C-peptide (rs2041139; 0.55 ug/L decrease per allele A; p-value = 1.4×10⁻⁴), LEPR and 1-hour C-peptide (rs1171278; 0.62 ug/L decrease per allele T; p-value = 2.4×10⁻⁴), and IL6 and 1-hour plasma glucose (rs6954897; −2.29 mg/dl decrease per allele G, p-value = 4.3×10⁻⁴).

Conclusions

Based on the genes surveyed in this study the inflammatory pathway is unlikely to have a strong impact on maternal metabolic phenotypes in pregnancy although variation in individual members of the pathway (e.g. RETN, IL8, ADIPOR2, LEPR, IL6, and TNF alpha,) may contribute to metabolic phenotypes in pregnant women.