Association of C-reactive protein (CRP) gene allelic variants with serum CRP levels and hypertension in Turkish adults

Genetics of ischemic stroke functional outcome

Ischemic stroke, which accounts for 87% of cerebrovascular accidents, is responsible for massive global burden both in terms of economic cost and personal hardship. Many stroke survivors face long-term disability-a phenotype associated with an increasing number of genetic variants. While clinical variables such as stroke severity greatly impact recovery, genetic polymorphisms linked to functional outcome may offer physicians a unique opportunity to deliver personalized care based on their patient's genetic makeup, leading to improved outcomes. A comprehensive catalogue of the variants at play is required for such an approach. In this review, we compile and describe the polymorphisms associated with outcome scores such as modified Rankin Scale and Barthel Index. Our search identified 74 known genetic polymorphisms spread across 48 features associated with various poststroke disability metrics. The known variants span diverse biological systems and are related to inflammation, vascular homeostasis, growth factors, metabolism, the p53 regulatory pathway, and mitochondrial variation. Understanding how these variants influence functional outcome may be helpful in maximizing poststroke recovery.

Association of C-reactive protein gene polymorphisms with the risk of ischemic stroke: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

The heterogeneous, complex condition known as ischemic stroke (IS) is brought on by the interaction of a number of risk factors and genetic variables. The association between C-reactive protein (CRP) gene polymorphisms and IS has, however, been the subject of inconsistent findings. Therefore, we conducted a meta-analysis to comprehensively address possible associations of CRP genes with the risk of IS.

METHODS

A comprehensive literature search for all the published articles was performed in electronic databases including PubMed, EMBASE, Cochrane Library, and Google Scholar from January 1, 1950 to June 30, 2022. Odds ratio (OR) with 95% Confidence interval (CIs) along with fixed/random effect models were used to calculate summary estimates.

RESULTS

Twelve case-control studies totalling 3880 IS cases and 5233 controls were included for the association of CRP gene polymorphisms (rs1800947, rs1130864, rs3093059, rs2794521, and rs1205). Across all genotyping models, we discovered that rs1130864, rs3093059, rs2794521, and rs1205SNPs were not substantially related to IS risk. A trend for significant association for rs1800947 under dominant (OR = 1.19; 95% CI = 0.97 to 1.48), recessive (OR = 1.49; 95% CI = 0.71 to 3.14) and allelic model (OR = 1.21; 95% CI = 0.99 to 1.48) was observed. However, protective association for rs1130864 under dominant (OR = 0.80; 95% CI = 0.70 to 0.91) and rs3093059 under allelic model (OR = 0.18; 95% CI = 0.14 to 0.22) was found.

CONCLUSION

Our thorough study revealed that the CRP gene variants rs1800947, rs1130864, rs3093059, rs2794521, and rs1205 could not be related to the risk of ischemic stroke. However, additional research must focus on the rs1800947 polymorphisms in a particular group.

CRP levels are significantly associated with CRP genotype and estrogen use in The Lifestyle, Biomarker and Atherosclerosis (LBA) study

Background

The C-reactive protein (CRP) is an important biomarker for atherosclerosis and single nucleotide polymorphisms (SNPs) in the CRP locus have been associated with altered CRP levels and associated with risk for cardiovascular disease. However, the association between genetic variations in the CRP gene, estrogen use and CRP levels or early signs of atherosclerosis in young healthy individuals is not fully characterized. We aimed to evaluate the influence of five genetic variants on both plasma CRP levels and carotid intima-media thickness (cIMT) values, including aspects on estrogen containing contraceptive use in females.

Methods

Genotyping was performed with TaqMan real time PCR and compared with high sensitivity CRP serum levels in 780 Swedish young, self-reported healthy individuals. Haplotypes of the SNPs were estimated with the PHASE v 2.1. The cIMT was measured by 12 MHz ultrasound. The contraceptive use was self-reported.

Results

Strong associations between CRP and genotype were observed for rs3091244, rs1800947, rs1130864, and rs1205 in women (all p < 0.001). In men, only rs1800947 was associated with CRP (p = 0.029). The independent effect of genotypes on CRP remained significant also after adjustment for established risk factors. Female carriers of the H1/ATGTG haplotype had higher CRP than non-carriers. This was specifically pronounced in the estrogen-using group (p < 0.001), and they had also higher cIMT (p = 0.002) than non-carriers but with a small cIMT difference between the haplotype groups (0.02 mm). In parallel, a significant correlation between CRP and cIMT in the estrogen using group was observed (r = 0.194; p = 0.026).

Conclusions

Estrogen use, genotypes and haplotypes in the CRP locus are significantly associated with CRP levels. Based on an observed interaction effect between sex/estrogen use and the H1/ATGTG haplotype on CRP, and a marginally thicker cIMT in the estrogen using group, our data suggest that both genotypes and estrogen usage could be involved in arterial wall structural differences. The causality between CRP levels and cIMT remains unclear, and the observed difference in cIMT is not clinically relevant in the present state. Future larger and longitudinal studies may shed further light on the role of more long-term estrogen use and early atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02610-z.

Sex-specific associations of TCF7L2 variants with fasting glucose, type 2 diabetes and coronary heart disease among Turkish adults

Objective:

TCF7L2 is a repressor and transactivator of genes, and its variants are strongly associated with diabetes. This study aimed to evaluate the sex-specific relationship between the most common TCF7L2 gene variants (-98368G>T, rs12255372 and -47833C>T, rs7903146) with diabetes and coronary heart disease in Turkish Adult Risk Factor (TARF) Study.

Methods:

Single nucleotide variants (SNVs) have been genotyped using the TaqMan allelic discrimination assays in 2,024 (51.3% in women, age: 55±11.8) Turkish adults participating in the TARF study. Statistical analyses were used to investigate the association of genotypes with clinical and biochemical measurements.

Results:

Among the TARF study participants, 11.7%, 24.3%, 14.1%, and 38.3% had diabetes, hypertension, coronary heart disease (CHD), and obesity, respectively. The frequencies of T allele for -47833C>T and -98368G>T in Turkish adults were determined to be 0.35 and 0.33, respectively. -47833C>T was significantly associated with higher fasting glucose concentrations in all participants, especially in men. Both SNVs were significantly associated with diabetes and CHD in all participants (p<0.05). When study population was stratified according to sex, -98368G>T was associated with diabetes in women (p=0.041) and -47833C>T was associated with diabetes and CHD in men (p=0.018 and p=0.032, respectively). Also, both SNVs and the diplotypes of common haplotype (H1) remained strongly associated with type 2 diabetes after risk factors were adjusted (p<0.05).

Conclusion:

T allele homozygosity of two SNVs as well as the diplotype H1-/H1- reflects risk of diabetes primarily in men. Enhanced CHD risk is determined by the presence of diplotype H1-/H1- among nondiabetic participants.

The effect of treated apical periodontitis before heart valve surgery on C-reactive protein levels

OBJECTIVE

Dental infections produce significant increases in systemic inflammatory responses manifested by cytokines and acute-phase reactants. This study evaluated the postoperative C-reactive protein (CRP) levels according to patients having teeth treated or not treated for apical periodontitis (AP) before heart valve surgery.

MATERIALS AND METHODS

Preoperative, postoperative third- and fifth-day CRP levels, and the previous dental data of 91 patients were investigated. Whether the patients had been treated for AP and whether they used antibiotic prophylaxis for this treatment were determined by examining the previous data. The analysis of covariance (ANCOVA) was used for statistical analysis.

RESULTS

There were no statistically significant differences in the preoperative CRP levels and the third-day CRP levels between all patients treated and those not treated for AP (p > .05). The mean fifth-day CRP levels of the patients with teeth treated for AP were significantly lower than those of the patients with teeth not treated for AP (p < .05). Antibiotic prophylaxis had a significant effect on the fifth-day CRP levels.

CONCLUSION

The decrease in CRP levels after AP treatment may contribute to alleviating heart valve disease and maintaining cardiac health.

Meta-Analysis on the Association of C-Reactive Protein Polymorphisms with Metabolic Syndrome

Polymorphisms in the C-reactive protein (CRP) genes might have crucial role in the development of metabolic syndrome (MetS). In the current comprehensive meta-analyses, we aim to provide a quantitative assessment of the association between CRP single-nucleotide polymorphisms (SNPs) and the risk of MetS. An electronic search was performed on several databases. After data extraction, random effect model was used to calculate the pooled odds ratio (OR) and 95% confidence intervals (CIs). Four independent studies including case–control, cohort, and cross-sectional methods were analyzed. Our meta-analysis indicated that CRP polymorphisms are not significantly associated with MetS (OR = 0.92, 95% CI = 0.77–1.10) with significant heterogeneity ( I²  = 55.4%; p -value = 0.008). The subgroup analysis revealed that only GG has significant association with MetS (OR = 0.32, 95% CI = 0.13–0.80, p -value = 0.015) without significant heterogeneity ( I²  = 0%, p -value > 0.05). In conclusion, this meta-analysis provides strong evidence that only some SNPs of CRP gene are associated with the risk for development of MetS; and this relationship does not exist in different ethnic populations.

Higher Serum C Reactive Protein Determined C Reactive Protein Single-Nucleotide Polymorphisms Are Involved in Inherited Depression

OBJECTIVE

The pathogenesis of depression is not fully understood yet, but studies have suggested higher circulating C reactive protein (CRP) level might relate to depression occurrence. However, due to high variability of patients' individual condition, the results to date are inconsistent. Considering CRP single-nucleotide polymorphisms (SNPs) could also regulate plasma CRP levels, in the present study, we hypothesized that inherited CRP allelic variations may co-vary with depressive symptomatology.

METHODS

We recruited 60 depression patients with family depression history and 60 healthy control volunteers into this project. We detected circulation CRP level as well as genome CRP SNPs from participants of this project.

RESULTS

We have found a significantly higher circulating CRP level in patients with a positive family history. Furthermore, we also identified some certain inherited CRP SNPs (A allele in rs1417938 and C allele in rs1205) could up regulate serum CRP level and distributed more in depression patients with family history.

CONCLUSION

Our finding may raise new evidence that genetically increased serum CRP level through SNPs variation is likely to induce family inherited depression.

Depression is Associated with CRP SNPs in Patients with Family History

Objective

The pathogenesis of depression is not fully understood, but studies have suggested that higher circulating levels of C reactive protein (CRP) might relate to depression occurrence. However, due to the highly variability of individual patients’ conditions, the results to date are inconsistent. Considering Single nucleotide polymorphisms (SNPs) of CRP gene have also been suggested to predict plasma CRP levels. In the present study, we hypothesize that inherited CRP allelic variations may co-vary with depressive symptomatology.

Methods

We recruited patients with a diagnosis of depression, with or without family depression history. We then detected serum CRP levels, as well as genome CRP SNPs from participants of this project.

Results

We found a significantly higher circulating CRP levels in patients with a positive family history. Furthermore, we also identified certain inherited CRP SNPs (A allele in rs1417938 and C allele in rs1205) which could up-regulate serum CRP levels and thus be associated with depression occurrence.

Conclusion

Our findings raise new evidence for the relationship between circulating CRP level and depression occurrence.

Relationship between polymorphisms in the CRP, LEP and LEPR genes and high sensitivity C-reactive protein levels in Spanish children

Background:

We investigated the association of single nucleotide polymorphisms (SNPs) in the C-reactive protein (

Methods:

We measured hs-CRP levels in 646 6–8-year-old and 707 12–16-year-old children using a high-sensitivity C-Reactive Protein ELISA kit. Four SNPs in the

Results:

The four CRP SNPs studied were significantly (p<0.05) associated with hs-CRP levels in both cohorts. Furthermore, two common CRP haplotypes (constructed using the SNPs in order: rs1205, rs1130864, rs1800947, rs2794521) ACGA and GCGG were associated with significantly lower CRP levels (p<0.05) at both ages. The LEPR SNPs rs1137100 (K109R) and rs1137101 (Q223R), and LEP SNP rs7799039 (G2548A) were also associated to hs-CRP levels (p<0.05) in both cohorts.

Conclusions:

hs-CRP levels in healthy Spanish children, besides being associated to common polymorphisms in the

Absence of association between -286C>A>T polymorphism in the CRP gene and metabolic syndrome in Iranian pediatric

BACKGROUND

As a common pathophysiological condition worldwide, metabolic syndrome (MetS) is a clustering of multiple risk factors implicating in the development of many chronic disorders. Of note, obesity-induced chronic, low-grade inflammation is a major cause of insulin resistance and MetS. In the present study, we evaluated the association of rs3091244 variant of the C-reactive protein (CRP) gene, a well-recognized systemic inflammatory marker, with MetS in Iranian children and adolescents.

MATERIALS AND METHODS

Genotyping was performed by mismatched polymerase chain reaction-restriction fragment length polymorphism in 100 MetS and 100 normal individuals aged 9-19 years recruited in the central part of Iran in 2011. A t-test or one-way ANOVA with post-hoc multiple comparisons were used to analyze the differences between groups. Statistical significance was defined as P ≤ 0.05. Logistic regression used to evaluate the association between alleles of the CRP rs3091244 and increased MetS risk.

RESULTS

There were no differences in the genotype frequencies or allele distribution for -286C>A>T CRP polymorphism between MetS and control groups. Logistic regression showed that only the T allele of the CRP rs3091244 and not any of the genotypes confers a borderline significant (P = 0.059) increased MetS risk compared to A allele with the odds ratio of 1.70 (0.98-2.96).

CONCLUSIONS

This study suggests that in Iranian children and adolescents, -286C>A>T CRP polymorphism is not associated with the increased risk for MetS.

Fcγ receptors and ligands and cardiovascular disease

Fcγ receptors (FcγRs) classically modulate intracellular signaling on binding of the Fc region of IgG in immune response cells. How FcγR and their ligands affect cardiovascular health and disease has been interrogated recently in both preclinical and clinical studies. The stimulation of activating FcγR in endothelial cells, vascular smooth muscle cells, and monocytes/macrophages causes a variety of cellular responses that may contribute to vascular disease pathogenesis. Stimulation of the lone inhibitory FγcR, FcγRIIB, also has adverse consequences in endothelial cells, antagonizing NO production and reparative mechanisms. In preclinical disease models, activating FcγRs promote atherosclerosis, whereas FcγRIIB is protective, and activating FcγRs also enhance thrombotic and nonthrombotic vascular occlusion. The FcγR ligand C-reactive protein (CRP) has undergone intense study. Although in rodents CRP does not affect atherosclerosis, it causes hypertension and insulin resistance and worsens myocardial infarction. Massive data have accumulated indicating an association between increases in circulating CRP and coronary heart disease in humans. However, Mendelian randomization studies reveal that CRP is not likely a disease mediator. CRP genetics and hypertension warrant further investigation. To date, studies of genetic variants of activating FcγRs are insufficient to implicate the receptors in coronary heart disease pathogenesis in humans. However, a link between FcγRIIB and human hypertension may be emerging. Further knowledge of the vascular biology of FcγR and their ligands will potentially enhance our understanding of cardiovascular disorders, particularly in patients whose greater predisposition for disease is not explained by traditional risk factors, such as individuals with autoimmune disorders.

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.

C-reactive protein gene variants: independent association with late-life depression and circulating protein levels

C-reactive protein (CRP) is a heritable biomarker of systemic inflammation that is commonly elevated in depressed patients. Variants in the CRP gene that influence protein levels could thus be associated with depression but this has seldom been examined, especially in the elderly. Depression was assessed in 990 people aged at least 65 years as part of the ESPRIT study. A clinical level of depression (DEP) was defined as having a score of ⩾16 on The Center for Epidemiologic Studies Depression scale or a diagnosis of current major depression based on the Mini-International Neuropsychiatric Interview and according to Diagnostic and Statistical Manual of Mental Disorders-IV criteria. Five single-nucleotide polymorphisms spanning the CRP gene were genotyped, and circulating levels of high-sensitivity CRP were determined. Multivariable analyses adjusted for socio-demographic characteristics, smoking, ischemic pathologies, cognitive impairment and inflammation-related chronic pathologies. The minor alleles of rs1130864 and rs1417938 were associated with a decreased risk of depression in women at Bonferroni-corrected significance levels (P=0.002). CRP gene variants were associated with serum levels in a gender-specific manner, but only rs1205 was found to be nominally associated with both an increased risk of DEP and lower circulating CRP levels in women. Variants of the CRP gene thus influence circulating CRP levels and appear as independent susceptibility factors for late-life depression.

Serum C-reactive protein level but not its gene polymorphism is associated with Takayasu arteritis

Takayasu arteritis (TA) patients with active disease often have elevated serum C-reactive protein (CRP) levels, which usually decline with the disease remission. The serum CRP concentration has been showed to be related to CRP gene polymorphisms in previous studies. The present study aims to investigate the associations of serum level of CRP and CRP polymorphisms with TA. A total of 178 unrelated Chinese Han TA patients and 229 unrelated Chinese Han individuals without documented disease were enrolled in our studies. After a systemic search in the HapMap database, four single-nucleotide polymorphisms (SNPs) were selected, namely, rs1800947, rs3093077, rs1205, and rs2808630. The ligase detection reaction (LDR) was used in genotyping. CRP concentrations were determined using turbidimetric immunoassay. Genotype frequencies and allele frequencies of CRP variations were similar between TA patients and controls. CRP haplotype frequencies in patients were not significantly different from those of controls. No significant association between serum CRP concentrations and genotypes was found. Moreover, no association was found in CRP concentration between patients with types I, II, and III TA or between patients with or without pulmonary involvement. By contrast, serum CRP concentration was directly correlated with disease severity. In conclusion, CRP polymorphisms were not associated with TA susceptibility or serum CRP levels in the Chinese Han population. However, higher CRP level was correlated with a more serious disease status, which implies that CRP possibly contributes to the progression of TA.

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.

The polymorphisms of C-reactive protein gene modify the association between central obesity and lung function in taiwan asthmatics

High-sensitivity C-reactive protein (hs-CRP) concentrations and obesity are proposed to have a significant relationship with impairment of lung function, but little has been reported to date on the association between CRP gene and lung function. We studied the association of three tagSNPs (tag single nucleotide polymorphisms) of CRP gene and their interactions with central obesity on lung function. A total of 384 asthmatic adults and 384 controls who were 1:1 matched by sex and age were recruited for this study. Three tagSNPs polymorphisms for CRP rs1417938, rs1800947 and rs1205 were selected from HapMap data and genotyping by using TaqMan allelic discrimination assay. A questionnaire interview, body composition and pulmonary function tests were performed. CRP single nucleotide polymorphisms (SNPs) did not increase the risk of asthma, but CRP rs1205 CC genotype significantly decreased the predictive value of forced vital capacity (FVC) in the asthma group (adjusted mean change = -7.54%, 95% CI = -13.82 to -1.25%). Waist-to-hip ratio, not body mass index, also decreased the predictive value of FVC in asthmatics. The subjects with central obesity who carried CRP SNPs have a significant reduction effect in lung function. The current results suggest that central obesity may play a major role in lung function, and these effects were modified significantly by the polymorphisms for CRP gene.

Genetic variants, immune function, and risk of pre-eclampsia among American Indians

PROBLEM

To determine the prevalence in an American Indian population of genetic variants with putative effects on immune function and determine if they are associated with pre-eclampsia (PE).

METHOD OF STUDY

In a study of 66 cases and 130 matched controls, six single nucleotide polymorphisms (SNP) with either previously demonstrated or postulated modulating effects on the immune system were genotyped. Allele frequencies and various genetic models were evaluated by conditional logistic regression in both univariate and multiply adjusted models.

RESULTS

Although most genetic variants lacked evidence of association with PE, the minor allele of the CRP related, rs1205 SNP in a dominant model with adjustment for age at delivery, nulliparity, and body mass index, exhibited an odds ratio of 0.259 (95% CI of 0.08-0.81, P=0.020) in relation to severe PE (48 cases). The allelic prevalence of this variant was 46.1% in this population.

CONCLUSION

Of the six SNPs related to immune function in this study, a functional variant in the 3'UTR of the CRP gene was shown to be associated with severe PE in an American Indian population.

Genetic variation in C-reactive protein in relation to colon and rectal cancer risk and survival

C-reactive protein (CRP), a biomarker of inflammation, has been shown to be influenced by genetic variation in the CRP gene. In this study, we test the hypothesis that genetic variation in CRP influences both the risk of developing colon and rectal cancer and survival. Two population-based studies of colon cancer (n = 1,574 cases, 1,970 controls) and rectal (n = 791 cases, 999 controls) were conducted. We evaluated four CRP tagSNPs: rs1205 (G > A, 3' UTR); rs1417938 (T > A, intron); rs1800947 (G > C, L184L); and rs3093075 (C > A, 3' flanking). The CRP rs1205 AA genotype was associated with an increased risk of colon cancer (OR 1.3, 95%CI 1.1-1.7), whereas the rs3093075 A allele was associated with a reduced risk of rectal cancer (OR 0.7, 95%CI 0.5-0.9). The strongest association for the rs1205 polymorphism and colon cancer was observed among those with KRAS2 mutations (OR 1.5, 95%CI 1.1-2.0). The CRP rs1205 AA genotype also was associated with an increased risk of CIMP+ rectal tumors (OR 2.5, 95%CI 1.2-5.3); conversely, the rs1417938 A allele was associated with a reduced risk of CIMP+ rectal tumors (OR 0.5, 95%CI 0.3-0.9). We observed interactions between CRP rs1800947 and BMI and family history of CRC in modifying risk of both colon and rectal cancer. These data suggest that genetic variation in the CRP gene influences risk of both colon and rectal cancer development.

Association between adolescent emotional problems and metabolic syndrome: the modifying effect of C-reactive protein gene (CRP) polymorphisms

Depression is associated with the development of the metabolic syndrome, and both depression and metabolic syndrome are associated with markers of systemic inflammation, such as C-reactive protein (CRP). We examined associations between affective status in adolescence and adulthood, and the metabolic syndrome at age 53 years in a large representative British birth cohort. We also investigated whether two CRP gene polymorphisms (rs1205 and rs3093068) were associated with affective status and the metabolic syndrome, and whether the association between affective status and the metabolic syndrome was modified by these CRP polymorphisms. Women, but not men, with emotional problems in adolescence were more likely to have the metabolic syndrome (OR=1.53, 95% CI: 1.04, 2.26), although this sex difference was not statistically significant (p=0.22). The CRP SNPs were not associated with affective status or the metabolic syndrome, but the association of adolescent emotional problems with the metabolic syndrome was stronger in those who were homozygous for the major allele (C) of rs1205 (OR=1.83, 95% CI: 1.17, 2.86) than in carriers of the T allele (OR=1.01, 95% CI: 0.66, 1.55) (p=0.05 for gene by affective status interaction). This interaction was stronger when considering adolescent emotional problems as a continuous variable (p=0.003). Adolescent emotional problems play an important role in the development of the metabolic syndrome later in life, particularly in those homozygous for the major allele of CRP rs1205. These findings may highlight new ways of identifying people with emotional problems at high risk of developing the metabolic syndrome, which is of great importance for the management of the physical health of these patients.

Polymorphism in the C-reactive protein (CRP) gene affects CRP levels in plasma and one early marker of atherosclerosis in men: The Health 2000 Survey

BACKGROUND

C-reactive protein (CRP) is an inflammatory protein that may play a role in the pathogenesis of cardiovascular disease (CVD). However, its status as a causal risk factor is still controversial. CRP gene single nucleotide polymorphisms (SNPs) have been shown to associate with CRP concentration, but not convincingly with early atherosclerotic changes.

OBJECTIVE

We assessed whether CRP genotypes or their haplotypes associate with plasma CRP levels or carotid artery intima-media thickness (IMT) or carotid artery elasticity (CAE) in a Finnish middle-aged study population.

METHODS

We genotyped CRP gene polymorphisms -717A>G (rs2794521), -286C>T>A (rs3091244), +1059G>C (rs1800947), +1444C>T (rs1130864) and +1846G>A (rs1205) and measured CRP concentration in a sub-population (N=1332, mean age 58.2 ± 8.0, women n=727 and men n=605) of a large Finnish cross-sectional health examination survey, The Health 2000 Study, carried out in 2000-2001. Results. Significant association (both sexes p<0.0001, women p=0.015 and men p=0.029) was found between CRP rs1800947 genotype and CRP concentration. Multivariate analysis showed an independent effect of the genotype on CRP concentration after adjustment for risk factors (women p=0.036 and men p=0.009). Similar associations were seen at the haplotype level in haplotype ACCCA where +1059 C-carriers had lower median CRP values than non-carriers (p=0.008). One CRP genotype (rs1130864) was associated with one CAE parameter in men but no association was observed between CRP genotypes and carotid artery IMT.

CONCLUSIONS

CRP gene allelic variation is associated with CRP levels in both sexes and with one CAE parameter (SI) in men in a population-based Finnish cohort of middle-aged subjects.

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.