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

The Association Between the C-Reactive Protein Gene Variants rs1130864 and rs2794521 and Obstructive Sleep Apnea in the Iranian Kurdish Population

Introduction: Obstructive sleep apnea (OSA) syndrome is a widespread multifactorial disorder that raises the risk of cardiovascular disease, diabetes, and Alzheimer's disease. This study aimed to investigate the association between the risk of OSA and two C-reactive protein (CRP) gene variants, rs1130864 and rs2794521. Materials and methods: In this study, 100 patients and 100 controls participated. Among 500 patients with OSA attending the sleep disorder center, 100 were randomly selected from those with apnea/hypopnea symptoms and daytime sleepiness. Polymerase chain reaction and restriction fragment length polymorphism of the CRP gene polymorphisms were used in this investigation. Results: The frequency of the mutant C allele was higher in the patient group than in the control group for the rs2794521 CRP gene variant (p ≤ 0.001), and the C allele elevated the risk of OSA by 2.584 times (odds ratios = 2.584, 95% confidence interval). The frequency of the mutant T allele was higher in the patient group than in the control group for the rs1130864 CRP gene variant, while the frequency of the C allele was higher in the control group, and this difference was statistically significant (p ≤ 0.001). Conclusions: Our findings indicated that rs1130864 and rs2794521 of the CRP gene are associated with increased risk for OSA. Extensive research is required to determine the role of distinct CRP gene variants in OSA.

The death rate of COVID-19 infection in different SARS-CoV-2 variants was related to C-reactive protein gene polymorphisms

The serum level of C-reactive protein (CRP) is a significant independent risk factor for Coronavirus disease 2019 (COVID-19). A link was found between serum CRP and genetic diversity within the CRP gene in earlier research. This study examined whether CRP rs1205 and rs1800947 polymorphisms were associated with COVID-19 mortality among various severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) variants. We genotyped CRP rs1205 and rs1800947 polymorphisms in 2023 deceased and 2307 recovered patients using the polymerase chain reaction-restriction fragment length polymorphism method. There was a significant difference between the recovered and the deceased patients in terms of the minor allele frequency of CRP rs1205 T and rs1800947 G. In all three variants, COVID-19 mortality rates were associated with CRP rs1800947 GG genotype. Furthermore, CRP rs1205 CC and rs1800947 GG genotypes showed higher CRP levels. It was found that the G-T haplotype was prevalent in all SARS-CoV-2 variants. The C-C and C-T haplotypes were statistically significant in Delta and Omicron BA.5 variants, respectively. In conclusion, polymorphisms within the CRP gene may relate to serum CRP levels and mortality among COVID-19 patients. In order to verify the utility of CRP polymorphism correlation in predicting COVID-19 mortality, a replication of these results is needed.

Association of - 717 A > G (rs2794521) CRP polymorphism with high cardiovascular risk by C-reactive protein in systemic lupus erythematosus patients

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease where genetic factors have been related to SLE susceptibility and disease severity. CRP polymorphisms have been associated with high C-reactive protein (CRP) serum levels, cardiovascular disease (CVD), and high clinical disease activity in SLE patients; however, the evidence is still inconclusive.

OBJECTIVE

This study was aimed to assess the association of the - 717 A > G, - 409 G > A, + 1444 C > T, and + 1846 C > T CRP polymorphisms with genetic susceptibility, clinical disease activity, and CVD risk in Mexican-mestizo SLE patients.

METHODS

A comparative cross-sectional study was conducted on 369 unrelated women: 183 with SLE according to the 1997 SLE-ACR criteria and 186 healthy subjects (HS). The clinical disease activity was assessed by the Mex-SLEDAI score; CRP and lipid profile were quantified by turbidimetry and colorimetric-enzymatic assays, respectively. The CRP polymorphisms genotyping was carried out by allelic discrimination.

RESULTS

SLE patients with - 717 AA genotype had higher CRP serum levels than SLE carriers of AG and GG genotypes (AA = 5 mg/L vs. AG = 3.2 mg/L vs. GG = 2.4 mg/L; p = 0.01), and the AA genotype was associated with high CVD risk by CRP in SLE patients (OR = 3; CI: 1.2-7.6; p < 0.01).

CONCLUSIONS

The - 717 A > G CRP polymorphism is a risk factor for high CRP levels and high CVD risk in Mexican-mestizo SLE patients. Key Points • Cardiovascular disease is one of the major causes of death in SLE patients due to the higher prevalence of traditional and non-traditional cardiovascular risk factors. • C-reactive protein is a liver-derived acute-phase protein suggested as one powerful independent risk predictor factor for cardiovascular disease. • Single nucleotide polymorphisms in CRP have been suggested as genetic susceptibility factors that could modify the SLE pathophysiology outcomes. • Mexican-mestizo SLE patients carrying the -717 A>G CRP AA genotype had 3-fold high cardiovascular disease risk than SLE patients with AG or GG genotypes.

Genetic variation in C-reactive protein (CRP) gene is associated with retinopathy and hypertension in adolescents with type 1 diabetes

BACKGROUND AND AIMS

Elevated concentration of CRP has been associated with the risk of diabetes as well as cardiovascular events and microvascular complications in T1D patients. We hypothesize that the +1846 C > T CRP gene polymorphism may have impact on the risk of T1D and/or its complications.

METHODS

We have examined 400 young patients with T1D and 250 healthy age-matched controls. The +1846 C > T CRP gene polymorphism was genotyped by ARMS-PCR method. The analysis covers microvascular complications, concentrations of serum pro- and anti-inflammatory markers, adhesion molecules, proangiogenic factor as well as blood pressure.

RESULTS

CT genotype (OR = 1.799) and T allele (OR = 1.733) are associated with increased risk of T1D, while CC genotype decreases the risk of this condition (OR = 0.458). Moreover, increased risk of hypertension corresponds with TT and T variant (OR = 3.116 and OR = 1.830, resp.) while CC genotype is decreasing the risk (OR = 0.547). Furthermore, CT variant is connected with lower risk of retinopathy (OR = 0.512) whereas TT variant decreases the risk of this complication (OR = 2.228). Our data also implies various effects of CRP +1846 C > T polymorphism on the inflammatory status of T1D patients.

CONCLUSIONS

Although further studies are required, the +1846 C > T CRP gene polymorphism could be considered a genetic marker to predict susceptibility to retinopathy and hypertension in T1D adolescents.

CRP Serum Levels Are Associated with High Cardiometabolic Risk and Clinical Disease Activity in Systemic Lupus Erythematosus Patients

Systemic lupus erythematosus (SLE) patients have a higher frequency of cardiovascular risk factors such as high C-reactive protein (CRP) levels than the general population. CRP is considered a cardiovascular disease marker that could be related to SLE clinical disease activity. This study aimed to assess the association between CRP with cardiometabolic risk and clinical disease activity in SLE patients. A comparative cross-sectional study was conducted in 176 female SLE patients and 175 control subjects (CS) with median ages of 38 and 33 years, respectively; SLE patients were classified by the 1997 SLE-ACR criteria, and the clinical disease activity by the Mexican-SLEDAI (Mex-SLEDAI). CRP and lipid profile (triglycerides, cholesterol, HDL-C, and LDL-C) were quantified by turbidimetry and colorimetric-enzymatic assays, respectively. SLE patients had higher CRP levels than CS (SLE: 5 mg/L vs. CS = 1.1 mg/L; p < 0.001). In SLE patients, CRP levels ≥ 3 mg/L were associated with a higher risk of cardiometabolic risk status assessed by LAP index (OR = 3.01; IC: 1.04−8.7; p = 0.04), triglycerides/HDL-C index (OR = 5.2; IC: 2.1−12.8; p < 0.001), Kannel index (OR = 3.1; IC: 1.1−8.1; p = 0.03), Castelli index (OR = 6.6; IC: 2.5−17.8; p < 0.001), and high clinical disease activity (OR = 2.5: IC: 1.03−6.2; p = 0.04; and β coefficient = 5.8; IC: 2.5−9.4; R2 = 0.15; p = 0.001). In conclusion, high CRP levels were associated with high cardiometabolic risk and clinical disease activity in SLE patients.

Innate-Immunity Genes in Obesity

The main functions of adipose tissue are thought to be storage and mobilization of the body’s energy reserves, active and passive thermoregulation, participation in the spatial organization of internal organs, protection of the body from lipotoxicity, and ectopic lipid deposition. After the discovery of adipokines, the endocrine function was added to the above list, and after the identification of crosstalk between adipocytes and immune cells, an immune function was suggested. Nonetheless, it turned out that the mechanisms underlying mutual regulatory relations of adipocytes, preadipocytes, immune cells, and their microenvironment are complex and redundant at many levels. One possible way to elucidate the picture of adipose-tissue regulation is to determine genetic variants correlating with obesity. In this review, we examine various aspects of adipose-tissue involvement in innate immune responses as well as variants of immune-response genes associated with obesity.

The Genetic Variants -717T>C (rs2794521), 1444G>A (rs1130864), and 1846 C > T (rs1205) of CRP Gene, Their Haplotypes, and Their Association with Serum CRP Levels, Acute Coronary Syndrome, and Diabetes in Patients from Western Mexico

Background: C-reactive protein (CRP) is involved in inflammatory pathways that are associated with the onset and progression of type 2 diabetes mellitus (T2DM) as well as an increased risk of an acute coronary syndrome (ACS). This research aimed to evaluate the potential association of the genetic variants -717T>C, 1444G>A, and 1846 C > T of CRP gene on CRP levels, ACS, and T2DM in participants from Western Mexico. Methods: Six hundred three participants were studied: (1) control group (CG); (2) ACS participants classified as unstable angina (UA), myocardial infarction without ST-segment elevation (NSTEMI), and myocardial infarction with ST-segment elevation (STEMI); (3) T2DM Participants; and (4) ACS plus T2DM participants (ACS+T2DM). Genetic variants were genotyped using allelic discrimination with TaqMan^® probes, and high-sensitivity CRP (hs-CRP) was measured by Turbidimetry. Results: TAC haplotype frequency was significantly higher in ACS+T2DM versus CG and versus ACS participants (odds ratio [OR] = 2.774, P = 0.017 and OR = 3.479, P = 0.020, respectively). hs-CRP levels were especially higher for ACS and for ACS+T2DM participants with respect to CG and T2DM (with P < 0.0001). We observed higher hs-CRP levels in NSTEMI and STEMI versus UA in ACS scenario (P = 0.001, P = 0.027, respectively) and for ACS+T2DM scenario (P = 0.0001, P = 0.002, respectively). Conclusion: hs-CRP level fluctuations are related to the presence of T2DM and the presence and severity of ACS. Very high levels (>10 mg/L) are a risk marker of cardiovascular complications. Our results demonstrate a possible relationship between TAC haplotype and an increased risk for T2DM and ACS.

Cardiovascular diseases and metabolic abnormalities associated with obesity: What is the role of inflammatory responses? A systematic review

INTRODUCTION

Obesity is a chronic disease responsible for a high morbidity and mortality rate, with an increasing worldwide prevalence. Obesity is associated with immune responses characterized by chronic systemic inflammation. This article focuses on the mechanisms that explain the proposed link between obesity-associated diseases and inflammation. Also, it describes the role of inflammatory molecules in obesity-associated metabolic abnormalities.

METHODS

More than 200 articles were selected and consulted by an online English search using various electronic search databases. Predefined key-words for the pathogenesis of obesity-induced inflammation and associated diseases, as well as the role of various inflammatory molecules, were used.

RESULTS

We have summarized the data of the articles consulted in this research and we have found that obesity is associated with a low-grade inflammation resulting from the change of adipose tissue (AT). The AT produces a variety of inflammatory molecules called adipocytokines that are involved in the onset of systemic low-grade inflammation which is the link between obesity and associated-chronic abnormalities; such as insulin resistance, metabolic syndrome, cardiovascular disease (CVD), hypertension, diabetes, and some cancers. Also, we have searched all the inflammatory molecules involved in this pathogenesis and we have briefly described the role of 16 of them which are the most related to obesity-associated inflammation. The results have shown that there are inflammatory molecules that have a positive relationship with the pathogenesis of obesity-related diseases and others have a negative relationship with this pathogenesis.

CONCLUSION

Inflammation plays a crucial role in the development of various metabolic-abnormalities related to obesity. In this regard, the management of obesity may help reduce the risk of cardiovascular disease and other metabolic complications by inhibiting inflammatory mechanisms.

Association of inflammatory genes in obstructive sleep apnea and non alcoholic fatty liver disease in Asian Indians residing in north India

BACKGROUND

Previous studies have indicated that variants of the high sensitive C-reactive protein (CRP), Interleukin (IL)-6 and leptin receptor (LEPR) genes are associated with the presence of obstructive sleep apnea (OSA) but not in non-alcoholic fatty liver disease (NAFLD) in Asian Indians. The study was conducted to investigate the association of CRP rs1130864 (1444C/T), IL-6 rs1800795 (-174G/C) and LEPR rs1137101 (Q223R) genes with OSA and NAFLD in Asian Indians residing in North India.

METHODS

240 overweight/ obese subjects [body mass index (BMI>23kg/m2)], 124 with OSA and with NAFLD (group 1), 47 with OSA without NAFLD (group 2), 44 without OSA and with NAFLD (group 3) and 25 without OSA and without NAFLD (group 4) were recruited in this study. The severity of NAFLD was based on abdomen liver ultrasound and of OSA on overnight polysomnography. Clinical details, anthropometry profile, body composition, biochemical parameters and inflammatory markers were measured. Polymerase chain reaction and restriction fragment length polymorphism of CRP, IL-6 and LEPR gene was performed. The associations of these polymorphisms with clinical, anthropometric and biochemical profiles were investigated. The genotypes were confirmed by DNA sequencing analysis.

RESULTS

The C, T and R alleles of IL-6, CRP and LEPR genes was more frequent in OSA and NAFLD subjects and significantly correlated with higher protein levels. The prevalence of variant genotypes C/T of CRP, G/C of IL-6 and Q/R of LEPR genes was significantly higher in OSA subjects as compared to non OSA subjects. Further, C/C genotype of IL-6 (G/C), T/T of CRP (C/T) and RR genotype of LEPR (Q/R) was associated with significantly higher BMI, fat mass (kg), % body fat, waist circumference, serum triglycerides, total cholesterol, alkaline phosphate, aspartate transaminase and fasting insulin levels in OSA and NAFLD subjects. Using a multivariate analysis, the combined effect of three polymorphisms of CRP, IL-6 and LEPR gene variants on OSA and NAFLD risk was evaluated. Odds ratio for OSA and NAFLD with the combination of the three gene polymorphisms increased to 2.84 (95% CI: 1.08-6.54; p = 0.04) even when adjusted for sex, age and BMI.

CONCLUSION

Polymorphisms of pro-inflammatory cytokine genes were associated with increased risk of OSA and NAFLD in Asian Indians.

CRP-level-associated polymorphism rs1205 within the CRP gene is associated with 2-hour glucose level: The SAPPHIRe study

C-reactive protein (CRP) encoded by CRP gene is a reflection of systemic inflammation. Many studies associated CRP level with diabetes and glucose levels, but the association of CRP gene with these traits is unclear. We conducted a cross-sectional study consisting of 945 siblings from 330 families collected by the Stanford Asian Pacific Program in Hypertension and Insulin Resistance (SAPPHIRe) to investigate associations between CRP polymorphisms, circulating CRP, diabetes, and glucose levels. Five single-nucleotide polymorphisms were analyzed: rs3093059, rs2794521, rs1417938, rs1800947, and rs1205. The generalized estimating equation approach was used to deal with correlated data within families. CRP level was positively correlated with diabetes prevalence and levels of fasting and 2-hour glucose (each P < 0.008). Alleles C at rs3093059 and G at rs1205 were associated with elevated CRP level (each P < 1.2 × 10⁻⁶). Allele C at rs3093059 was associated with fasting glucose (β = 0.20, P = 0.045) and G at rs1205 was associated with 2-hour glucose (β = 0.46, P = 0.00090) post oral glucose tolerance test, but only the latter passed Bonferroni correction. No polymorphism was associated with diabetes. Since 2-hour glucose is an indicator of glucose tolerance, this study indicated CRP gene is associated with glucose intolerance.

Genetic Epidemiology of Type 2 Diabetes in Mexican Mestizos

There are currently about 415 million people with diabetes worldwide, a figure likely to increase to 642 million by 2040. In 2015, Mexico was the second Latin American country and sixth in the world in prevalence of this disorder with nearly 11.5 million of patients. Type 2 diabetes (T2D) is the main kind of diabetes and its etiology is complex with environmental and genetic factors involved. Indeed, polymorphisms in several genes have been associated with this disease worldwide. To estimate the genetic epidemiology of T2D in Mexican mestizos a systematic bibliographic search of published articles through PubMed, Scopus, Google Scholar, and Web of Science was conducted. Just case-control studies of candidate genes about T2D in Mexican mestizo inhabitants were included. Nineteen studies that met the inclusion criteria were found. In total, 68 polymorphisms of 41 genes were assessed; 26 of them were associated with T2D risk, which were located in ABCA1, ADRB3, CAPN10, CDC123/CAMK1D, CDKAL1, CDKN2A/2B, CRP, ELMO1, FTO, HHEX, IGF2BP2, IRS1, JAZF1, KCNQ1, LOC387761, LTA, NXPH1, SIRT1, SLC30A8, TCF7L2, and TNF-α genes. Overall, 21 of the 41 analyzed genes were associated with T2D in Mexican mestizos. Such a genetic heterogeneity compares with findings in other ethnic groups.

Does bilirubin protect against developing diabetes mellitus?

After 25 years of evaluating bilirubin as a possible protective agent in neonatal and cardiovascular disease, interest has moved on to a exploring a possible protective role in diabetes mellitus (DM). This review finds conflicting prospective data for a protective relationship though there are retrospective, case-controlled data, that can only show association, which is not causality. Only prospective studies can show causality. Also, it would appear that the underlying biochemical assumptions do not readily translate from the animal to the human setting. Given that many factors impact on circulating bilirubin levels, it is not surprising that a clear-cut answer is not available; the jury is still out. Any relationship between DM and bilirubin might relate to intermediates in bilirubin metabolism, including relationships involving the genes for the enzymes participating in those steps. Nevertheless, the pursuit of bilirubin in disease causation is opening new avenues for research and if it is established that serum bilirubin can predict risks, much will have been achieved. The answer may have to come from molecular genetic analyses.

The relationship between C-reactive protein rs3091244 polymorphism and ankylosing spondylitis

AIMS

Previous studies have shown that C-reactive protein (CRP) gene polymorphism can be related to inflammatory changes. The present study aimed to examine the association between CRP gene polymorphism and clinical and laboratory findings in ankylosing spondylitis (AS) patients.

MATERIALS AND METHODS

A total of 80 patients, 40 with AS and 40 controls, were included in the study. Diagnosis of AS was made according to Assessment in AS International Working Group criteria. Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Metrology Index and Bath Ankylosing Spondylitis Radiology Index scores were evaluated. CRP gene C, A and T alleles were evaluated and were determined using the analysis of melting curves after real time polymerase chain reaction. The odds ratios were calculated for all alleles and haploids of the CRP gene. We investigated the relationship between the CRP polymorphism and clinical and laboratory findings.

RESULTS

A, C, T allele frequencies in the control group were 15%, 57.5% and 27.5%. The allele frequencies in the AS group were 38%, 68.8% and 26.2%. While C and T allele frequencies were shown to be similar in the two groups, A allele frequency was higher in the AS group compared to the control group. The CC wild allele was 42.5% in the control group and 47.5% in the AS group (P = 1.0). Odds ratios for the C allele were 1.6, for the CC haploid 1.2 and for the CT haploid 3.7. Chest expansion and finger-to-ground distance was better in the CRP gene polymorphism group compared to the no polymorphism group.

CONCLUSION

The presence of the CRP gene CC wild haploid and C allele in patients may indicate an increased risk for AS.

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.