Association between C-reactive protein gene haplotypes and C-reactive protein levels in Taiwanese: interaction with obesity

Dietary magnesium, C-reactive protein and interleukin-6: The Strong Heart Family Study

OBJECTIVES

To examine the associations of dietary Mg intake with inflammatory biomarkers (C-reactive protein (CRP) and interleukin 6 (IL-6)), and the interaction of dietary Mg intake with single nucleotide polymorphism (SNP) rs3740393, a SNP related to Mg metabolism and transport, on CRP and IL-6 among American Indians (AIs).

METHODS

This cross-sectional study included AI participants (n = 1,924) from the Strong Heart Family Study (SHFS). Mg intake from foods and dietary supplements was ascertained using a 119-item Block food frequency questionnaire, CRP and IL-6 were measured from blood, and SNP rs3740393 was genotyped using MetaboChip. Generalized estimating equations were used to examine associations of Mg intake, and the interaction between rs3740393 and dietary Mg, with CRP and IL-6.

RESULTS

Reported Mg intake was not associated with CRP or IL-6, irrespective of genotype. A significant interaction (p-interaction = 0.018) was observed between Mg intake and rs3740393 on IL-6. Among participants with the C/C genotype, for every 1 SD higher in log-Mg, log-IL-6 was 0.04 (95% CI: -0.10 to 0.17) pg/mL higher. Among participants with the C/G genotype, for every 1 SD higher in log-Mg, log-IL-6 was 0.08 (95% CI: -0.21 to 0.05) pg/mL lower, and among participants with the G/G genotype, for every 1 SD higher in log-Mg, log-IL-6 was 0.19 (95% CI: -0.38 to -0.01) pg/mL lower.

CONCLUSIONS

Mg intake may be associated with lower IL-6 with increasing dosage of the G allele at rs3740393. Future research is necessary to replicate this finding and examine other Mg-related genes that influence associations of Mg intake with inflammation.

Rare functional variants in the CRP and G6PC genes modify the relationship between obesity and serum C-reactive protein in white British population

BACKGROUND

C-reactive protein (CRP) is a sensitive biomarker of inflammation with moderate heritability. The role of rare functional genetic variants in relation to serum CRP is understudied. We aimed to examine gene mutation burden of protein-altering (PA) and loss-of-function (LOF) variants in association with serum CRP, and to further explore the clinical relevance.

METHODS

We included 161,430 unrelated participants of European ancestry from the UK Biobank. Of the rare (minor allele frequency <0.1%) and functional variants, 1,776,249 PA and 266,226 LOF variants were identified. Gene-based burden tests, linear regressions, and logistic regressions were performed to identify the candidate mutations at the gene and variant levels, to estimate the potential interaction effect between the identified PA mutation and obesity, and to evaluate the relative risk of 16 CRP-associated diseases.

RESULTS

At the gene level, PA mutation burdens of the CRP (β = -0.685, p = 2.87e-28) and G6PC genes (β = 0.203, p = 1.50e-06) were associated with reduced and increased serum CRP concentration, respectively. At the variant level, seven PA alleles in the CRP gene decreased serum CRP, of which the per-allele effects were approximately three to seven times greater than that of a common variant in the same locus. The effects of obesity and central obesity on serum CRP concentration were smaller among the PA mutation carriers in the CRP (pinteraction  = 0.008) and G6PC gene (pinteraction  = 0.034) compared to the corresponding non-carriers.

CONCLUSION

PA mutation burdens in the CRP and G6PC genes are strongly associated with decreased serum CRP concentrations. As serum CRP and obesity are important predictors of cardiovascular risks in clinics, our observations suggest taking rare genetic factors into consideration might improve the delivery of precision medicine.

Roles of C-reactive protein polymorphisms and life event changes on cognitive function in bipolar patients receiving valproate

Introduction

Patients with bipolar disorder (BD) exhibit an inflamed condition that is associated with metabolic disturbance and cognitive impairment. Whether inflammation, represented by C-reactive protein (CRP), is causally associated with BD and influences treatment outcome has not been established.

Methods

We examined whether CRP is a causal factor for the risk of BD in drug-naïve, depressed BD patients and investigated whether polymorphisms in CRP and life event changes influence cognitive function in BD patients receiving valproate (VPA) treatment.

Results

Our results showed that BD patients had significantly higher CRP levels and worse cognitive function than the controls, while the frequencies of CRP single nucleotide polymorphisms in BD patients and in controls were not different. In addition, the life event scale score was higher for BD patients than for controls. Furthermore, the genotypes of CRP polymorphisms and the interactions between polymorphisms of CRP and life event scale score had a significant influence on cognitive performance in BD patients after 12 weeks of VPA treatment.

Conclusion

Our study demonstrated the clinical utility of the application of functional genetics in clarifying the interactions among CRP, life event stress, and BD and suggested the important roles of CRP gene–environment interactions in developing treatment strategies for BD.

Quantile-dependent expressivity of serum C-reactive protein concentrations in family sets

Background

“Quantile-dependent expressivity” occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g., C-reactive protein, CRP) is high or low relative to its distribution. We have previously shown that the heritabilities (h²) of coffee and alcohol consumption, postprandial lipemia, lipoproteins, leptin, adiponectin, adiposity, and pulmonary function are quantile-specific. Whether CRP heritability is quantile-specific is currently unknown.

Methods

Serum CRP concentrations from 2,036 sibships and 6,144 offspring-parent pairs were analyzed from the Framingham Heart Study. Quantile-specific heritability from full-sib (β_FS, h² ={(1 + 8r_spouseβ_FS)^0.5 − 1}/(2r_spouse)) and offspring-parent regression slopes (β_OP, h² = 2β_OP/(1 + r_spouse)) were estimated robustly by quantile regression with nonparametric significance determined from 1,000 bootstrap samples.

Results

Quantile-specific h² (±SE) increased with increasing percentiles of the offspring’s age- and sex-adjusted CRP distribution when estimated from β_OP (P_trend = 0.0004): 0.02 ± 0.01 at the 10th, 0.04 ± 0.01 at the 25th, 0.10 ± 0.02 at the 50th, 0.20 ± 0.05 at the 75th, and 0.33 ± 0.10 at the 90th percentile, and when estimated from β_FS (P_trend = 0.0008): 0.03±0.01 at the 10th, 0.06 ± 0.02 at the 25th, 0.14 ± 0.03 at the 50th, 0.24 ± 0.05 at the 75th, and 0.53 ± 0.21 at the 90th percentile.

Conclusion

Heritability of serum CRP concentration is quantile-specific, which may explain or contribute to the inflated CRP differences between CRP (rs1130864, rs1205, rs1800947, rs2794521, rs3091244), FGB (rs1800787), IL-6 (rs1800795, rs1800796), IL6R (rs8192284), TNF-α (rs1800629) and APOE genotypes following CABG surgery, stroke, TIA, curative esophagectomy, intensive periodontal therapy, or acute exercise; during acute coronary syndrome or Staphylococcus aureus bacteremia; or in patients with chronic rheumatoid arthritis, diabetes, peripheral arterial disease, ankylosing spondylitis, obesity or inflammatory bowel disease or who smoke.

Genetic factors associated with obesity risks in a Kazakhstani population

Objectives

There is limited published literature on the genetic risks of chronic inflammatory related disease (eg, obesity and cardiovascular disease) among the Central Asia population. The aim is to determine potential genetic loci as risk factors for obesity for the Kazakhstani population.

Setting

Kazakhstan.

Participants

One hundred and sixty-three Kazakhstani nationals (ethnic groups: both Russians and Kazakhs) were recruited for the cross-sectional study. Linear regression models, adjusted for confounding factors, were used to examine the genetic associations of single nucleotide polymorphisms (SNPs) in 19 genetic loci with obesity (73 obese/overweight individuals and 90 controls).

Results

Overall, logistic regression analyses revealed genotypes C/T in CRP (rs1205), A/C in AGTR1 (rs5186), A/G in CBS (rs234706), G/G in FUT2 (rs602662), A/G in PAI-1 (rs1799889), G/T (rs1801131) and A/G (rs1801133) in MTHFR genes significantly decrease risk of overweight/obesity. After stratification for ethnicity, rs234706 was significantly associated with overweight/obesity in both Russians and Kazakhs, while rs1800871 was significant in Kazakhs only.

Conclusions

This study revealed that variations in SNPs known to be associated with cardiovascular health can also contribute to the risks of developing obesity in the population of Kazakhstan.

Association of serum C-reactive protein level and polymorphisms with susceptibility to dengue infection and severe clinical outcome among eastern Indian patients

Dengue virus (DENV) infection is a major public health concern in India ranging from simple febrile illness to severe outcome. This study aimed to investigate association of serum CRP level and CRP gene polymorphisms towards development of dengue disease susceptibility and severity among eastern Indian patients. Blood was collected from 348 symptomatic patients. Sera was subjected to serological diagnosis for the presence of anti-dengue IgM, anti-dengue IgG antibodies and dengue NS1 antigen by ELISA. Viral RNA was extracted and the presence of DENV genome, viral load, serotypes was determined by qRT-PCR. CRP level and polymorphisms were determined by immunoturbidimetry and polymerase chain reaction-restriction fragment length polymorphism, respectively. Statistical analysis was performed by GraphPad-Prism. Among 206 dengue patients, CRP level increased significantly among patients within acute phase, and patients with qRT-PCR/NS1 antigen positivity, high viral load (HVL), secondary infection, and DENV4 and DENV2 infections. rs3091244, TT genotype positively associated with dengue susceptibility (p = 0.03). CT genotype of rs3093059 and TT genotype of rs3091244 were found to correlate with elevated CRP level and development of WHO-defined warning signs. TT genotype of rs3091244 was more prevalent among HVL patients. Thus, these CRP polymorphic variants and CRP concentration might act as potential prognostic biomarkers for predicting disease severity among acute-stage dengue patients.

C-Reactive Protein Gene Variants and Their Serum Levels in Early Adult-onset Type 2 Diabetes Mellitus

BACKGROUND/AIM

C-Reactive protein (CRP) is a common marker of inflammation. Elevated CRP levels have been associated with increased risk of development of type 2 diabetes mellitus (T2DM). This study aimed to evaluate the association of CRP gene polymorphisms with early-onset T2DM and the effect of genetic variants on CRP level.

MATERIALS AND METHODS

In total, 948 individuals with early-onset (n=271) or late-onset (n=677) T2DM were enrolled in the study. Five single-nucleotide polymorphisms (SNPs) in the CRP gene, namely rs3093077, rs2808630, rs1800947, rs11265263, and rs11265265, were selected for genotyping, and CRP levels were measured.

RESULTS

Genotypic, allelic, and haplotype frequencies of these five SNPs were not significantly different between patients with early- and those with late-onset. T2DM Higher serum CRP levels were independently associated with the C-allele of rs3093077 and T-allele of rs11265265 (p<0.001). Furthermore, the C-allele of rs3093077 was associated with higher CRP level in both early- (p=0.016) and late-onset (p<0.001) T2DM.

CONCLUSION

CRP gene variants may contribute to the risk of early-onset T2DM by affecting the serum CRP level.

CRP genetic variants are associated with mortality and depressive symptoms in chronic heart failure patients

OBJECTIVE

Heart failure (HF) is a complex medical condition with a multitude of genetic and other factors being involved in the pathogenesis. Emerging evidence points to an involvement of inflammatory mechanisms at least in subgroups of patients. The same is true for depression and depressive symptoms, which have a high prevalence in HF patients and are risk factors for the development and outcomes of cardiovascular disease.

METHODS

In 936 patients of the Interdisciplinary Network Heart Failure (INH) program, CRP and IL-6 protein blood levels were measured and genetic variants (single nucleotide polymorphisms) of the CRP and IL6 gene analyzed regarding their influence on mortality.

RESULTS

Less common recessive genotypes of two single nucleotide polymorphisms in the CRP gene (rs1800947 and rs11265263) were associated with significantly higher mortality risk (p < 0.006), higher CRP levels (p = 0.029, p = 0.006) and increased depressive symptoms in the PHQ-9 (p = 0.005, p = 0.003). Variants in the IL-6 gene were not associated with mortality.

CONCLUSION

Our results hint towards an association of less common CRP genetic variants with increased mortality risk, depressive symptoms and peripheral CRP levels in this population of HF patients thereby suggesting a possible role of the inflammatory system as link between poor prognosis in HF and depressive symptoms.

Elevated levels of C-reactive protein and IL-6 among the antipsychotic medicating schizophrenia patients of Siliguri, West Bengal, India

PURPOSE

Chronic, low-grade inflammation is a proposed etiological factor associated with schizophrenia. Thus, various studies have been conducted to understand the role of inflammatory process in schizophrenia by using inflammatory maker C-reactive protein (CRP) with conflicting findings. Inadvertently, studies of CRP among the Indian schizophrenia patients are very few. Therefore, the present study was undertaken to investigate the role of inflammatory process among Indian Bengalee schizophrenia patients of Siliguri, using the marker CRP and its stimulating cytokine interleukin-6 (IL-6). In addition, the study also intended to investigate the immunomodulatory effect of antipsychotic medication on serum levels of CRP and IL-6.

MATERIALS AND METHODS

The serum levels of CRP and IL-6 were measured by Enzyme-Linked Immunosorbent Assay (ELISA) among 67 antipsychotic medicating, 28 psychotropic medication-free schizophrenia patients, and it was compared with 72 age, sex and ethnicity-matched controls.

RESULTS

A significantly higher level of CRP and IL-6 were recorded among the antipsychotic medicating patients. Although CRP was found to be higher among the psychotropic medication-free patients than the controls, it was not found to be significant. However, a significantly higher level of IL-6 was observed in this group.

CONCLUSIONS

The results provide the evidence for a possible immunomodulatory effect of antipsychotic drugs on CRP. Future investigations including the study of antipsychotics separately may help to understand the differential effects of individual antipsychotics on CRP level. Additional studies with a larger sample size of psychotropic medication-free patients may help to verify the role of inflammation in schizophrenia patients of this region.

Gene-physical activity interactions in lower extremity performance: inflammatory genes CRP, TNF-α, and LTA in community-dwelling elders

We assessed gene-gene and gene-physical activity interactions of polymorphisms in C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and lymphotoxin α (LTA) genes on lower extremity performance in community-dwelling elders in Taiwan. Five SNPs (rs1205, rs1130864, rs1800947, rs2794520, and rs3093059) of CRP gene, three SNPs (rs909253, rs1041981, and rs2239704) of LTA gene, and three SNPs (rs3093662, rs1800629, and rs1799964) of TNF-α gene of 472 unrelated elders were genotyped. Lower extremity performance included timed up-and-go test (TUG), walking speed, weight-adjusted leg press (waLP), and timed chair stand (TCS). We detected significant interactions between physical activity with CRP rs2794520, rs1205, and rs3093059; LTA rs909253 and rs1041981; and TNF-α rs1799964 for TCS in women after covariate adjustment (all P < 0.05). In men, significant interactions between physical activity with CRP rs2794520, rs1205, and rs3093059; and LTA rs909253 and rs1041981 for TUG; with CRP rs2794520, rs1205, rs1130864, and rs3093059; and LTA rs909253 and rs1041981 for walking speed; and with TNF-α rs3093662 for waLP after covariate adjustment (all P < 0.05). These variants also significantly interacted with physical activity on TCS in women and on walking speed in men. These results show inflammatory genes are involved in lower extremity performance, likely via gene-physical activity interactions.

CRP and SAA1 Haplotypes Are Associated with Both C-Reactive Protein and Serum Amyloid A Levels: Role of Suppression Effects

To test the statistical association of the CRP and SAA1 locus variants with their corresponding circulating levels and metabolic and inflammatory biomarker levels by using mediation analysis, a sample population of 599 Taiwanese subjects was enrolled and five CRP and four SAA1 variants were genotyped. Correlation analysis revealed that C-reactive protein (CRP) and serum amyloid A (SAA) levels were significantly associated with multiple metabolic phenotypes and inflammatory marker levels. Our data further revealed a significant association of CRP and SAA1 variants with both CRP and SAA levels. Mediation analysis revealed that SAA levels suppressed the association between SAA1 genotypes/haplotypes and CRP levels and that CRP levels suppressed the association between CRP haplotypes and SAA levels. In conclusion, genetic variants at the CRP and SAA1 loci independently affect both CRP and SAA levels, and their respective circulating levels act as suppressors. These results provided further evidence of the role of the suppression effect in biological science and may partially explain the missing heritability in genetic association studies.

Genetic Association Studies Reporting on Variants in the C-Reactive Protein Gene and Coronary Artery Disease: A Meta-Analysis

C-reactive protein (CRP) is a commonly used inflammatory marker and elevated CRP levels are shown to increase the risk of coronary artery disease (CAD). Sequence variations in the CRP gene believed to influence the protein levels have been extensively investigated in CAD community. Most of the published studies, however, have reported mixed findings. The objective of the present study was to examine the associations of CRP variants (+942G>C, -717A>G, +1444C>T) with genetic risk of CAD by use of a meta-analysis.The human case-control studies were identified through online search, hand search, and contacting the authors of original articles. We performed both random-effect and fixed-effect meta-analysis to estimate CAD risk (odds ratios, OR). This analysis combined 16 studies in total. We found +942G>C was not associated with CAD risk when all data were pooled together, nor did we find a significant association in subgroup analyses. Meta-analysis of +1444C>T studies showed a similar trend. However, a borderline association with CAD risk was revealed for -717A>G (random-effect: OR = 0.53, 95% CI = 0.28-1.00 for the homozygous model; random-effect: OR = 0.51, 95% CI = 0.26-1.00 for the recessive model).These data suggest that the CRP gene variants examined may not modulate CAD risk.

C-reactive protein genetic variant is associated with diabetic retinopathy in Chinese patients with type 2 diabetes

BACKGROUND

Diabetic retinopathy (DR) is an important microvascular complication of diabetes with a high concordance rate in patients with diabetes. Inflammation is supposed to participate in the development of DR. This study aimed to investigate whether genetic variants of CRP are associated with DR.

METHODS

A total of 1,018 patients with type 2 diabetes were recruited in this study. Of these patients, 618 were diagnosed with DR, 400 were patients with diabetes for over 10 years but without DR, considered as cases and controls for DR, respectively. Four tagging SNPs (rs2808629, rs3093077, rs1130864 and rs2808634) within CRP region were genotyped for all the participants. Fundus photography was performed for diagnosis and classification for DR.

RESULTS

rs2808629 was significantly associated with increased susceptibility to DR (odds ratio 1.296, 95% CI 1.076-1.561, P = 0.006, empirical P = 0.029, for G allele). This association remained significant after adjustment for confounding factors (odds ratio 1.261, 95% CI 1.022-1.555, P = 0.030).

CONCLUSIONS

In this study, we found CRP rs2808629 was associated with DR in the Chinese patients with type 2 diabetes.

Effect of obesity on the association between common variations in the PPAR gene and C-reactive protein level in Chinese Han population

The peroxisome proliferator-activated receptors (PPARs)-α, -β/δ, and -γ are the ligand-activated transcription factors that function as the master regulators of glucose, fatty acid and lipoprotein metabolism, inflammation, and atherosclerosis. Our aim was to test the association between ten single nucleotide polymorphisms of PPARs and CRP level, as well as their interaction with overweight/obesity. A sample population of 643 subjects was recruited from the prevention of MetS and multi-metabolic disorders in Jiangsu Province of China Study. The selected SNPs in PPAR α (rs135539, rs4253778, rs1800206), PPAR β/δ (rs2016520 and rs9794), and PPAR γ (rs10865710, rs1805192, rs709158, rs3856806, and rs4684847) were genotyped. After adjustment for smoking, alcohol consumption, SBP, DBP, TG, and HDL-C, rs1800206, rs709158, rs1805192, and rs4684847 polymorphisms were significantly associated with CRP level in normal weight subjects (P < 0.05). In the overweight/obese subjects, rs1800206 was also significant associated with CRP level (P<0.01). In addition, the rs709158, rs1805192, and rs4684847 polymorphisms were shown interactions with overweight/obesity to influence CRP level (P<0.05). PPARs polymorphisms are independently associated with CRP levels in Chinese Han population. Further, PPARs polymorphisms interact with overweight/obesity to set CRP levels.

Association of CRP gene polymorphism with CRP levels and Coronary Artery Disease in Type 2 Diabetes in Ahvaz, southwest of Iran

Introduction: We evaluated the association between four polymorphisms in the CRP gene with serum C-reactive protein (CRP) levels, prevalence and severity of coronary artery disease (CAD) in type 2 diabetes mellitus (T2DM) patients.

Methods: We performed coronary angiography for 308 T2DM patients and classified them into two groups: T2DM with CAD and T2DM without CAD. All patients were from Ahvaz, Iran. serum levels of CRP, glucose and lipid profile were measured. Genotyping was performed by PCR/RFLP, and the severity of coronary artery disease was determined by Gensini score.

Results: The GG genotype of SNP rs279421 was associated with the increased risk of CAD (OR= 2.38; 95% CI: 1.12- 5.8; p= 0.02) and CA, TT, TA genotypes and A allele of SNP rs3091244 and GA genotypes and A allele of SNP rs3093062 were significantly associated with increased CRP levels. None of genotypes or alleles was associated with Gensini score. We found that the haplotype 7 (AGCG) was associated with decreased risk of CAD (OR= 0.11; 95% CI: 0.02, 0.66; p= 0.017) and the Gensini score was correlated with increased levels of CRP, only in CAD group.

Conclusion: Although genetic polymorphisms were influenced on serum RP levels, none of the alleles and genotypes raising or falling C-reactive protein levels was consistently associated with an increased prevalence of CAD or protected from that.

Association of CRP gene polymorphisms with serum CRP level and handgrip strength in community-dwelling elders in Taiwan: Taichung Community Health Study for Elders (TCHS-E)

Low handgrip strength is one component of frailty, characterized by loss of reserves, including energy, physical ability, cognition and health. This study rated the effect of five single-nucleotide polymorphisms (SNPs) in C-reactive protein (CRP) gene on the serum CRP level and handgrip strength in elderly Taiwanese. Five SNPs (rs2794520, rs1205, rs1130864, rs1800947, and rs3093059) of CRP gene were utilized to genotype 472 unrelated elderly subjects (mean age 73.8years). Handgrip strength was measured by handgrip dynamometer (TTM Dynamometer, Tsutsumi, Tokyo). Our study demonstrated that minor alleles of rs2794520 and rs1205 were C, whereas they were T in most ethnic groups. There exist significant associations of three CRP polymorphisms (rs2794520, rs1205 and rs3093059) with serum CRP level and handgrip strength. All three had simultaneous influence on raising CRP levels and reducing handgrip strength. Genotype and sex interactions emerged for rs2794520 and rs1205 in relation to CRP levels (p<0.05). In addition, haplotype C-C-C-C-C was associated with higher levels of CRP (exp(β)=1.45; p<0.001) and lower handgrip strength (β=-1.00kg, p<0.05). We conclude that SNPs rs2794520, rs1205, and rs3093059 of CRP gene, as well as haplotype C-C-C-C-C may be important biomarkers for susceptibility to low handgrip strength and high serum CRP level in elders; further studies are required.

Role of C-reactive protein in schizophrenia: an overview

Over the years, schizophrenia is speculated to be associated with immune or inflammatory reactions mediated by cytokines. It is proposed that chronic inflammation might damage the micro-vascular system of brain and hamper cerebral blood flow. Scientific evidence suggests that an increase of stress hormone like norepinephrine may activate the inflammatory arm of the immune system and trigger the expression of genes that cause chronic, low-grade inflammation. Thus, studies were conducted to decipher the potentiality of CRP as a marker for inflammation in schizophrenia. This article reviews the findings of CRP in schizophrenia, and the limitations of the previous studies have been discussed. The importance of simultaneous study of CRP modulating cytokines and CRP gene polymorphism in the study of serum or plasma level of CRP has been emphasized.

C-reactive protein 1059G/C gene polymorphism, C-reactive protein levels and acute myocardial infarction

AIMS

High-sensitivity C-reactive protein (hs-CRP) is an inflammatory marker, predicting the occurrence of acute myocardial infarction (AMI). Genetic predisposition to high baseline CRP might account for a high risk of heart diseases. Our study aimed at investigating an association of CRP 1059G/C gene polymorphism with plasma CRP levels and AMI in Egyptian patients.

METHODS

Genotypes of 150 patients with AMI and 150 healthy sex and age-matched controls were analyzed using PCR-restriction fragment length polymorphism methods. hs-CRP concentrations were assessed.

RESULTS

There was no significant association between CRP 1095G/C polymorphism and AMI. However, individuals with GG genotype had significantly higher plasma CRP concentration than those with GC and CC genotypes, in both controls (3.82 ± 1.03 vs. 2.34 ± 0.7; P = 0.001) and patients with AMI (8.39 ± 2.6 vs. 6.67 ± 2.4; P = 0.005).

CONCLUSION

Our results revealed that CRP 1059G/C gene variation influences plasma CRP levels. Conversely, this polymorphism was not associated with the risk for AMI.

Genetic variants associated with circulating MMP1 levels near matrix metalloproteinase genes on chromosome 11q21-22 in Taiwanese: interaction with obesity

BACKGROUND

MMP1 is implicated in the pathogenesis of atherothrombotic cardiovascular disease. We aimed to elucidate genetic determinants of inflammatory marker levels, including circulating MMP1, in Taiwanese, and their association with obesity.

METHODS

Five genetic polymorphisms around matrix metalloproteinase genes on chromosome 11q21-22 region were genotyped in 519 subjects.

RESULTS

After adjusting for clinical covariates, two polymorphisms were significantly associated with MMP1 levels, rs1799750 and rs495366, using an additive inheritance model (P = 1.5x10-4 and P = 2.57x10-5, respectively). Using dominant model, minor alleles of rs1799750 and rs495366 were associated with higher MMP1 levels (P = 1.3x10-4 and P = 1.95x10-5, respectively). In haplotype analysis, two haplotypes inferred from five SNPs (A2GATA and A1GATG) were associated with MMP1 levels (P = 5x10-4 and P = 8.47x10-5, respectively). Subgroup and interaction analysis revealed an association of rs1799750 and rs495366 with MMP1 levels only in non-obese subjects (P = 6.66x10-6 and P = 4.38x10-5, respectively, and interaction P = 0.008 for rs1799750). Haplotype interaction analysis also showed significant interaction for haplotype A1GATG (interaction P = 0.003).

CONCLUSIONS

Genotypes/haplotypes around MMP1 locus are associated with MMP1 levels in Taiwanese. Further, since genotypes/haplotypes near MMP1 locus interact with obesity to set MMP1 levels, genetic determinants for MMP1 level may be different between obese and non-obese individuals.

C-reactive protein, early life stress, and wellbeing in healthy adults

OBJECTIVE

To determine whether C-reactive protein (CRP) can serve as a marker for alterations in immune function prior to the manifestation of significant psychiatric and medical disorders.

METHOD

Ninety-two healthy adults were recruited from the community and determined to be free of psychiatric or medical disorders. The concentration of plasma CRP from a single resting sample was examined in relation to current mental and physical health as well as to self-reported history of early life adversity.

RESULTS

C-reactive protein showed a significant positive correlation with body mass index (BMI; r = 0.477, P < 0.001). Non-specific pain, fatigue, and lower overall quality of physical health were all associated with higher CRP concentrations (all P < 0.05 or P < 0.01), after controlling for effect of BMI and other relevant covariates. Subthreshold depression symptoms and other indices of mental/emotional wellbeing were not associated with CRP, nor was CRP significantly linked to any measures of early life adversity.

CONCLUSION

Lower-quality physical health and wellbeing, but not the presence of mood/anxiety symptoms or early life stress (ELS), were significantly related to plasma CRP. Elevated CRP does not appear to be a fundamental consequence of ELS among healthy adults.

Haplotypes in the CRP gene associated with increased BMI and levels of CRP in subjects with type 2 diabetes or obesity from Southwestern Mexico

Objective. We evaluated the association between four polymorphisms in the CRP gene with circulating levels of C-reactive protein (CRP), type 2 diabetes (T2D), obesity, and risk score of coronary heart disease. Methods. We studied 402 individuals and classified them into four groups: healthy, obese, T2D obese, and T2D without obesity, from Guerrero, Southwestern Mexico. Blood levels of CRP, glucose, cholesterol, triglycerides, and leukocytes were measured. Genotyping was performed by PCR/RFLP, and the risk score for coronary heart disease was determined by the Framingham's methodology. Results. The TT genotype of SNP rs1130864 was associated with increased body mass index and T2D patients with obesity. We found that the haplotype 2 (TGAG) was associated with increased levels of CRP (β = 0.3; 95%CI: 0.1, 0.5; P = 0.005) and haplotype 7 (TGGG) with higher body mass index (BMI) (β = 0.2; 95%CI: 0.1, 0.3; P < 0.001). The risk score for coronary heart disease was associated with increased levels of CRP, but not with any polymorphism or haplotype. Conclusions. The association between the TT genotype of SNP rs1130864 with obesity and the haplotype 7 with BMI may explain how obesity and genetic predisposition increase the risk of diseases such as T2D in the population of Southwestern Mexico.

Relationship between CRP polymorphism and cardiovascular events in Chinese peritoneal dialysis patients

BACKGROUND AND OBJECTIVES

The single-nucleotide polymorphism (SNP) -717A→G substitution, rs2794521, was found in the promoter of the C-reactive protein (CRP) gene. Functional studies showed that A allele promoter has higher transcriptional activity than the G allele. This study investigated the association between this SNP and the outcome of Chinese patients undergoing peritoneal dialysis (PD).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The study included 441 new PD patients (232 men; mean age ± SD, 56.7±13.5 years). CRP genotyping was determined; patients were followed for 41.3±18.3 months for cardiovascular events.

RESULTS

For the entire cohort, 5-year event-free survival rates did not differ between the AA and AG/GG groups (35.7% and 31.9%, respectively; P=0.64). However, there was significant interaction between plasma cholesterol levels and CRP genotype groups on event-free survival (P=0.04 for interaction). For patients with cholesterol levels of 200 mg/dl or greater, the 5-year event-free survival rate in the AG/GG group was significantly better than that in the AA group (54.7% versus 40.0%; P=0.04), whereas there was no difference in event-free survival between genotype groups for patients with cholesterol levels less than 200 mg/dl.

CONCLUSIONS

CRP gene -717AG or GG genotypes is associated with cardiovascular benefit to Chinese PD patients with cholesterol levels of 200 mg/dl or greater. These findings suggest a complex interaction among cholesterol, CRP, and cardiovascular disease in PD patients.

Single-nucleotide polymorphisms at five loci are associated with C-reactive protein levels in a cohort of Filipino young adults

C-reactive protein (CRP) is a component of nonspecific immune defense and is a reliable marker of low-grade inflammation involved in obesity, type 2 diabetes and cardiovascular disease. Genome-wide association studies in middle-aged and elderly populations, predominantly of European descent, demonstrated associations of CRP levels with single-nucleotide polymorphisms (SNPs) at several loci. To examine whether the variants identified are replicated in Filipino young adults, we applied Tobit regression models to study the association of plasma CRP with 12 SNPs at seven loci in a cohort of 1691 Filipino young adults (aged 21.5±0.3 years) from the Cebu Longitudinal Health and Nutrition Survey. SNPs in or near CRP (P=3.2 × 10(-11)), HNF1A, IL6R, APOE-APOC1 and LEPR showed significant associations (P<0.05) and together explained 4.8% of the total variation in CRP. Modest interactions were observed between LEPR-rs1892534 and waist circumference (uncorrected P(interaction)=0.020) and between APOE-rs769449 and pathogen exposure (uncorrected P(interaction)=0.0073) in models predicting CRP. Our results demonstrated that variants in several loci are significantly associated with plasma CRP in Filipino young adults, suggesting shared genetic influences on circulating CRP across populations and age groups.

CRP gene variation affects early development of Alzheimer's disease-related plaques

Introduction

We used the Tampere Autopsy Study (TASTY) series (n = 603, age 0-97 yrs), representing an unselected population outside institutions, to investigate the pathogenic involvement of inflammation in Alzheimer's disease-related lesions.

Methods

We studied senile plaque (SP), neurofibrillary tangles (NFT) and SP phenotype associations with 6 reported haplotype tagging single nucleotide polymorphisms (SNPs) in the CRP gene. CRP and Aβ immunohistochemistry was assessed using brain tissue microarrays.

Results

In multivariate analyses (age- and APOE-adjusted), non-neuritic SP were associated with the high-CRP TA-genotype (3.0% prevalence) of rs3091244 and CA-genotype (10.8%) of rs3093075 compared to common genotypes. Conversely, the low-CRP C allele (39.3%) of rs2794521 reduced the risk of harbouring early non-neuritic SP, compared to the TT genotype. CRP haplotype TAGCC (high) associated with non-neuritic SP, whereas haplotype CCGCC offered protection. TT genotypes (high) of rs3091244 and rs1130864 were associated with CRP staining. There were no associations between SNPs or haplotypes and NFT. CRP staining of the hippocampal CA1/2 region correlated with Aβ staining.

Conclusions

CRP gene variation affects early SP development in prodromal Alzheimer's disease, independent of APOE genotype.

Effect of obesity on the association between ATF3 gene haplotypes and C-reactive protein level in Taiwanese

OBJECTIVE

ATF3 has traditionally been related to various inflammatory processes. Our aim was to test the statistical association between variations in the ATF3 gene and levels of nine serum inflammatory markers, including C reactive protein (CRP), in a Taiwanese population using interaction analysis.

METHODS

A sample population of 604 Taiwanese subjects was enrolled. Five tagging single nucleotide polymorphisms of the ATF3 gene from the Han Chinese HapMap Database were selected and genotyped.

RESULTS

With or without adjustment for clinical covariates, ATF3 genotypes were found to be associated with CRP levels but not with other inflammatory marker levels. Minor alleles of 2 of the 5 ATF3 SNPs were associated with decreased CRP levels predominantly in non-obese subjects (Bonferoni P=0.018, and P=0.002 for rs11571530, and rs10475, respectively). Two haplotypes inferred from the 5 SNPs, GATTA and TACCA, were also associated with increased or decreased CRP levels, respectively, in non-obese subjects (Bonferoni P=0.012 and P=0.01, respectively) but not in obese subjects. Interaction analysis revealed interaction of obesity with an ATF3 genotype associated with a high CRP level (interaction P=0.006 for SNP rs10475). An effect of obesity on CRP level was also noted in haplotype interaction analysis (interaction P=0.019 for haplotype TACCA).

CONCLUSIONS

ATF3 polymorphisms are independently associated with CRP levels in Taiwanese subjects. Further, ATF3 genotypes/haplotypes interact with obesity to set CRP levels. These findings may have implications for the prediction of atherosclerotic disease.

Association of C-reactive protein gene polymorphisms and colorectal cancer

BACKGROUND

An elevated plasma level of C-reactive protein (CRP) is a risk for, and prognostic factor of, colorectal cancer (CRC). In other reports of CRP concerning cardiovascular disease, CRP level correlated with its gene polymorphisms. We hypothesized that CRP polymorphisms associate risk and prognosis of CRC.

METHODS

This study enrolled 421 patients with CRC and 218 healthy control subjects. After preliminary studies, we selected four single nucleotide polymorphisms (SNPs) in the CRP gene: +2147A > G (rs1205), +942G > C (rs1800947), -717A > G (rs2794521), and -757T > C (rs3093059). At first, analyzing distributions of four SNPs between CRC case and non-CRC control groups was performed. Subsequently, the impacts of these SNPs with other prognostic factors of disease-free interval (DFI) and cancer-specific survival (CSS) were analyzed using uni- and multivariate Cox regression analyses.

RESULTS

The case and control groups differed in the frequency of -757T > C (P = 0.002). The CRC case group had a higher percentage of the TT genotype (odds, 1.75). Regarding prognoses, multivariate analyses revealed that four factors, including stage (I, II, III), gross tumor type (polypoid, ulcerative, infiltrative), location (right, left, rectum), and -757T > C SNP (odds, 1.29; P = 0.048), correlated with DFI; two factors, including stage and +2147A > G SNP (odds, 0.71; P = 0.03), correlated with CSS.

CONCLUSIONS

The -757T > C SNP is a risk for and prognostic factor of DFI; the +2147A > G SNP is a prognostic factor of CSS. CRP polymorphisms associate the risk and survival of CRC.

Inflammatory gene variants in the Tsimane, an indigenous Bolivian population with a high infectious load

The Tsimane of lowland Bolivia are an indigenous forager-farmer population living under conditions resembling pre-industrial European populations, with high infectious morbidity, high infection and inflammation, and shortened life expectancy. Analysis of 917 persons ages 5 to 60+ showed that allele frequencies of 9 SNPs examined in the apolipoprotein E (apoE), C-reactive protein (CRP), and interleukin-6 (IL-6) genes differed from some European, African, and north Asian-derived populations. The apoE2 allele was absent, whereas four SNPs related to CRP and IL-6 were monomorphic: CRP (rs1800947, rs3093061, and rs3093062) and IL-6 (rs1800795). No significant differences in apoE, CRP, and IL-6 variants across age were found CRP levels were higher in carriers of two CRP proinflammatory SNPs, whereas they were lower in carriers of apoE4. Taken together the evidence for (1) different allele frequencies between the Tsimane and other populations and (2) the correlations of CRP and apoE alleles with blood CRP may suggest that these variants are under selection in response to a high infection environment.

Association between functional variants of the ICAM1 and CRP genes and metabolic syndrome in Taiwanese subjects

Although inflammation has been shown to play an important role in metabolic syndrome (MetS), the association between inflammatory marker gene polymorphisms and the risk of MetS has not been fully elucidated. This study was initiated to investigate the association between functional variants of inflammatory marker genes and the risk of MetS in Taiwanese adults. The sample population comprised 615 unrelated subjects, of which 22% had MetS. The single nucleotide polymorphisms rs5491 on the intercellular adhesive molecule 1 (ICAM1) gene and rs3091244 on C-reactive protein (CRP) were genotyped. The ICAM1 rs5491 polymorphism was significantly associated with the level of soluble intercellular adhesive molecule 1 (P < .001). Both the ICAM1 rs5491 and the CRP rs3091244 were shown to have significant association with MetS after adjustment for age, sex, smoking, and body mass index, but not after adjustment for levels of the respective serum marker. Independent associations between the combined ICAM1-CRP (rs5491 and rs3091244) genotypes and MetS were found by multivariate analysis (P = .005). In subgroup analysis, association of combined genotypes with insulin resistance and MetS mainly occurred in subjects with central obesity. In conclusion, inflammatory marker gene polymorphisms play an important role in modulating the risk of insulin resistance and MetS for subjects with central obesity. These findings will contribute toward a better understanding of the mechanism of association between inflammatory markers and the risk of developing atherosclerotic disease.

Effect of central obesity, low high-density lipoprotein cholesterol and C-reactive protein polymorphisms on C-reactive protein levels during treatment with Rosuvastatin (10 mg Daily)

Plasma levels of high-sensitivity C-reactive protein (hsCRP) are an important predictor of cardiovascular disease, and achievement of lower targets of hsCRP with rosuvastatin treatment was associated with improved cardiovascular outcomes. The aim of this study was to examine whether hsCRP levels were related to genetic variants and traditional cardiovascular risk factors in Chinese patients treated with rosuvastatin 10 mg/day. The relations were analyzed between on-treatment plasma hsCRP concentrations and cardiovascular risk factors and 14 single-nucleotide polymorphisms in CRP and other candidate genes. In 281 patients with a median plasma hsCRP level of 0.81 mg/L (interquartile range 0.46 to 1.86), higher hsCRP levels were significantly associated with female gender, greater waist circumference (WC), having diabetes, higher triglycerides, and lower high-density lipoprotein (HDL) cholesterol. Three single-nucleotide polymorphisms (rs1205, 3872G>A and rs2808630, 5237A>G in CRP and rs1169288, I27L in HNF1A) were independently associated with hsCRP levels before and after adjustment for other variables. WC and the CRP rs1205 polymorphism showed the strongest relations with hsCRP, and in multiple regression analysis, gender, WC, diabetes, triglycerides, HDL cholesterol, and the 3 genetic variants explained 35.5% of the variance in hsCRP levels. The 2 CRP polymorphisms, female gender, higher WC, and lower HDL cholesterol were associated with risk for having CRP concentrations ≥ 1 mg/L. In conclusion, central obesity, low HDL cholesterol, and CRP polymorphisms are major determinants of higher hsCRP levels in Chinese patients receiving treatment with rosuvastatin.

Genetic variants of the inflammatory C-reactive protein and schizophrenia in Armenian population: a pilot study

C-reactive protein (CRP) is an inflammation marker implicated in the pathogenesis of schizophrenia. To investigate association of the CRP rs1417938, rs1800947, rs1205 variants with susceptibility to schizophrenia 208 unrelated Armenians (103 patients and 105 healthy controls) were genotyped. In this pilot study, none of studied variants was associated with schizophrenia.

Insulin resistance is associated with C-reactive protein independent of abdominal obesity in nondiabetic Taiwanese

Insulin resistance, which plays a fundamental role in the pathogenesis of metabolic syndrome and type 2 diabetes mellitus, is associated with serum levels of inflammatory markers and abdominal obesity. Whether insulin resistance is caused by inflammation or is an epiphenomenon of obesity remains unresolved. We therefore conducted a cross-sectional study to investigate whether the association between insulin resistance and C-reactive protein (CRP) levels is independent of abdominal obesity in a nondiabetic Taiwanese population. The study included 574 Taiwanese participants (300 men and 274 women) who were nondiabetic persons with CRP levels not exceeding 10 mg/L and who did not have a history of cardiovascular disease or were taking medication for dyslipidemia. All participants were of Han-Chinese origin. The degree of insulin resistance was determined using the homeostasis model assessment of insulin resistance (HOMA-IR). The CRP levels were categorized into quartiles from the lowest to the highest concentrations (Q1-Q4). Blood pressure, fasting glucose level, triglycerides level, waist circumference, and HOMA-IR were all found to be significantly higher in Q3 and Q4 than in Q1 and Q2. Stratified analysis by sex and abdominal obesity showed that HOMA-IR was significantly associated with CRP levels in both sexes in either obese or nonobese populations. Multiple linear regression analysis adjusting for age, smoking, components of metabolic syndrome, and waist circumference showed that the association between HOMA-IR and CRP levels remained significant in both men and women (P = .029 for men and P < .001 for women). These findings confirm that insulin resistance is strongly associated with CRP levels independent of abdominal obesity in nondiabetic Taiwanese. Factors other than abdominal obesity, such as polymorphisms in the CRP gene, may influence the association of insulin resistance with CRP levels in different ethnic populations.

Implications of genetic polymorphisms in inflammation-induced atherosclerosis

Inflammation is the mainstay of atherosclerosis and is an important governing factor at all stages of the disease process from lesion formation to plaque build-up and final end-stage rupture and thrombosis. An overview of the numerous clinico-epidemiological studies on the association between inflammatory gene polymorphisms and Cardiovascular disease (CVD) and its co-morbidities have shown that the risk associated with any single genotype is modest while the haplotypes, especially those defined on the basis of tag-SNP approach, have better coverage of the gene and show moderately higher impact on disease risk. Nevertheless, even these associations have been inconsistent with low cross-race repeatability. This has been attributed to many plausible causes such as clinical heterogeneity, sample selection criteria, variable genetic landscapes across different ethnic groups, confounding effect of co-morbidities etc. On the other hand, unbiased studies such as the family-based linkage and case-control based associations that have taken into account, thousands of genotypic markers spanning the whole genome, have had the ability to identify novel genetic loci for coronary artery disease. These studies have shown that many inflammatory genes are involved in the regulation of specific biomarkers of inflammation that collectively contribute to the disease-associated risk. In addition, there appears to be considerable cross talk between the different biochemical and metabolic processes. Therefore, consideration of all these factors can build towards an 'atherosclerotic bionetwork' that can refine our quest for developing a robust risk stratification tool for cardiovascular disease.