Jacqueline P. Smith

Statin use in rheumatoid arthritis in relation to actual cardiovascular risk: evidence for substantial undertreatment of lipid-associated cardiovascular risk?

Background Cardiovascular disease (CVD) is partially attributed to traditional cardiovascular risk factors, which can be identified and managed based on risk stratification algorithms (Framingham Risk Score, National Cholesterol Education Program, Systematic Cardiovascular Risk Evaluation and Reynolds Risk Score). We aimed to (a) identify the proportion of at risk patients with rheumatoid arthritis (RA) requiring statin therapy identified by conventional risk calculators, and (b) assess whether patients at risk were receiving statins. Methods Patients at high CVD risk (excluding patients with established CVD or diabetes) were identified from a cohort of 400 well characterised patients with RA, by applying risk calculators with or without a ×1.5 multiplier in specific patient subgroups. Actual statin use versus numbers eligible for statins was also calculated. Results The percentage of patients identified as being at risk ranged significantly depending on the method, from 1.6% (for 20% threshold global CVD risk) to 15.5% (for CVD and cerebrovascular morbidity and mortality) to 21.8% (for 10% global CVD risk) and 25.9% (for 5% CVD mortality), with the majority of them (58.1% to 94.8%) not receiving statins. The application of a 1.5 multiplier identified 17% to 78% more at risk patients. Conclusions Depending on the risk stratification method, 2% to 26% of patients with RA without CVD have sufficiently high risk to require statin therapy, yet most of them remain untreated. To address this issue, we would recommend annual systematic screening using the nationally applicable risk calculator, combined with regular audit of whether treatment targets have been achieved.

Association of interleukin-6 (IL-6)-174G/C gene polymorphism with cardiovascular disease in patients with rheumatoid arthritis: The role of obesity and smoking

BACKGROUND Cardiovascular morbidity and mortality are increased in rheumatoid arthritis (RA). Interleukin-6 (IL-6) is high in RA and, together with smoking and obesity, an important contributor to the development of cardiovascular disease (CVD). The present study examined the potential association of IL-6-174 G/C polymorphism, together with obesity and smoking, with the presence of CVD in RA patients. METHODS AND RESULTS DNA samples were collected from 383 RA patients (who also had extensive clinical and laboratory evaluations). IL-6-174 G/C was identified using real time PCR and melting curve analysis. Serum IL-6 levels were measured in a subgroup of 135 RA patients to examine the functionality of the polymorphism. Carriers of the IL6-174C-allele demonstrated increased prevalence of CVD (26.2% vs. 17.0%, p=0.041). There was a significant association with CVD, even after adjustment for traditional CVD risk factors (OR=1.92, 95%CI: 1.03 to 3.58, p=0.041). IL-6 levels were significantly increased in C-allele carriers [14.02 (3.21-38.81) vs. 4.48 (2.25-16.5), p=0.028]. No significant interactions were observed between adiposity and IL6-174G/C genotypes. There was only a trend for an interaction between ever smoking and IL6 C-allele carriers on CVD. CONCLUSION The IL-6-174C-allele may associate with CVD in RA patients and possibly exerts its effect via increased inflammation. This finding, if confirmed in future studies, may be used as a part of a genetic screening tool for RA patients at high CVD risk.

Rheumatoid arthritis susceptibility genes associate with lipid levels in patients with rheumatoid arthritis

Introduction Rheumatoid arthritis (RA), a systemic inflammatory disease with complex genetic aetiology, associates with excess cardiovascular morbidity and mortality. Dyslipidaemia, a major cardiovascular risk factor has been reported to predate the onset of RA, thus suggesting a potential genetic link between the two conditions. The authors assessed whether RA susceptibility genes associate with the presence of dyslipidaemia in RA patients. Methods 400 well-characterised RA patients were included in this cross-sectional study. Fasting lipid profile (total cholesterol, high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides, apolipoproteins (ApoA and ApoB) and lipoprotein (a)) and four RA susceptibility genes (PTPN22, TRAF1/C5, STAT4 and human leucocyte antigen shared epitope (HLA-SE)) were assessed and associations were sought in both univariate and multivariate analyses. Results Following adjustment for age, sex and erythrocyte sedimentation rate, the G allele of TRAF1/C5 associated with lower total cholesterol (p=0.010), LDL (p=0.022) and ApoB (p=0.014); one or more copies of the shared epitope associated with lower ApoA (p=0.035) and higher ApoB:ApoA ratio (p=0.047); while STAT4 TT homozygotes had higher lipoprotein (a) (p=0.004). Conclusions RA susceptibility genes (TRAF1/C5, STAT4 and HLA-DRB1-SE) may be involved in the regulation of lipid metabolism in RA patients, thus contributing to cardiovascular disease (CVD) risk and adverse outcome. If these findings are replicated, such genotyping could be used to identify and target for prevention those RA patients most at risk of CVD. It will also be interesting to study the association of these genes with lipid levels in the general population and identify mechanisms to explain the link.

Lymphotoxin 252A>G polymorphism is common and associates with myocardial infarction in patients with rheumatoid arthritis

OBJECTIVE Cardiovascular disease (CVD) is more prevalent and more likely to lead to death in patients with rheumatoid arthritis (RA). Single nucleotide polymorphisms of the genes for lymphotoxin-A (LT-A) and its regulatory protein galectin-2 (LGALS2) have been implicated as genetic risk factors for acute cardiovascular events in the general population: we hypothesised that their risk alleles/genotypes (a) may be more frequent among patients with RA compared with non-RA controls (thus explaining some of the increased CVD in RA), and (b) may be more frequent among patients with RA with prevalent CVD compared with patients with RA without CVD. METHODS Genomic DNA samples were collected from 388 patients with RA and 399 local population controls without RA. LT-A gene intron 1 252A>G and LGALS2 intron 1 3279C>T single nucleotide polymorphisms were identified using real-time polymerase chain reaction and melting curve analysis. RESULTS LT-A 252GG homozygotes were significantly more prevalent among patients with RA compared with controls (19.8% vs 11.8%, p = 0.002; OR(GG/GA,AA) = 1.85, 95% CI 1.25 to 2.75, p = 0.002). Patients with RA possessing LT-A 252 GG were significantly more likely to have had a myocardial infarction compared with those with LT-A 252 AA or GA (13% vs 5.5%, p = 0.02; adjusted OR(GG/GA,AA) = 3.03, 95% CI 1.2 to 7.68, p = 0.002). The frequency of LGALS2 polymorphisms was similar between RA and controls and was not associated with CVD among patients with RA. CONCLUSIONS The LT-A 252GG genotype occurs more frequently among patients with RA than the general population. In RA, this genotype appears to associate with increased likelihood of suffering an myocardial infarction.

Are Lipid Ratios Less Susceptible to Change With Systemic Inflammation Than Individual Lipid Components in Patients With Rheumatoid Arthritis

Rheumatoid arthritis (RA) associates with excess cardiovascular risk and there is a need to assess that risk. However, individual lipid levels may be influenced by disease activity and drug use, whereas lipid ratios may be more robust. A cross-sectional cohort of 400 consecutive patients was used to establish factors that influenced individual lipid levels and lipid ratios in RA, using multiple regression models. A further longitudinal cohort of 550 patients with RA was used to confirm these findings, using generalized estimating equations. Cross-sectionally, higher C-reactive protein (CRP) levels correlated with lower levels of total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and high-density lipoprotein-cholesterol ([HDL-C] P ≤ .015), whereas lipid ratios did not correlate with CRP. The findings were broadly replicated in the longitudinal data. In summary, the effects of inflammation on individual lipid levels may underestimate lipid-associated cardiovascular disease (CVD) risk in RA, thus lipid ratios may be more appropriate for CVD risk stratification in RA.

Polymorphisms of the Endothelin-1 Gene Associate with Hypertension in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) associates with excess cardiovascular (CV) morbidity and mortality. Hypertension, a highly prevalent entity in RA, has been associated with the endothelin-1 (ET-1) gene locus (EDN1) in some groups, such as Afro-Caribbean, the obese, and in low-renin states, but not in the general population as a whole. High levels of plasma ET-1 have been observed in RA. This study evaluated the potential association of EDN1 gene locus and serum ET-1 levels with hypertension in patients with RA. Genomic DNA and serum samples were collected from 397 well-characterized RA patients; DNA was also available from 401 local general population controls without RA. To explore the overall relevance of EDN1, two suitable single-nucleotide polymorphisms (SNPs), rs1800541 and rs5370, were selected and haplotype analysis was performed. Both SNPs were identified using real-time polymerase chain reaction (PCR) and melting curve analysis. Genetic analysis was related to hypertension as dichotomous trait and to blood pressure indices as continuous variables. Serum endothelin levels were also assessed in the RA patients. No genotype or haplotype differences were observed between RA and control subjects. Within RA, logistic regression analysis of each SNP separately revealed a threefold increase in the adjusted odds of being hypertensive of rs5370 TT homozygotes compared to GG homozygotes (OR = 2.89, 95%CI: 1.02 to 8.19). After adjustment for multiple potential confounders, haplotype analysis revealed an additive effect of the rs1800541-rs5370 T-T haplotype on hypertension (OR = 2.96, 95%CI: 1.28 to 6.86; p = .011), systolic blood pressure (SBP) (beta = 6.75 +/- 2.57 mm Hg; p = .009), and pulse pressure (PP) (beta = 4.37 +/- 2.12 mm Hg; p = .040). There was an increased prevalence of raised ET-1 levels amongst hypertensive RA patients, whereas a similar trend was observed for T-T haplotype carriers. RA patients who carry the rs1800541-rs5370 T-T EDN1 haplotype appear more likely to be hypertensive with an increased SBP and PP. These findings, if replicated in future studies, could be used as a screening tool for RA patients at increased hypertension, and thus cardiovascular, risk.

Association of the TRAF1/C5 locus with increased mortality, particularly from malignancy or sepsis, in patients with rheumatoid arthritis.

OBJECTIVE Recent genome-wide association studies have identified TRAF1/C5 as a rheumatoid arthritis (RA) susceptibility locus. Tumor necrosis factor receptor-associated factor 1 (TRAF1) has been implicated in the regulation of antiapoptotic pathways, whereas C5 has a well-established role in defense against infection. The purpose of this study was to examine the association of the TRAF1/C5 locus with death in patients with RA. METHODS Genomic DNA samples were collected from a prospective cohort of 400 RA patients. TRAF1/C5 rs3761847 was identified using real-time polymerase chain reaction and melting curve analyses. The association of TRAF1/C5 rs3761847 alleles with the risk of death was assessed using Cox proportional hazards regression analyses. RESULTS TRAF1/C5 rs3761847 GG homozygote status was associated with an increased risk of death (hazard ratio 3.96 [95% confidence interval 1.24-12.6], P=0.020) as compared with AA homozygote status. The excess mortality was attributed to deaths due to malignancies and sepsis but not cardiovascular disease (CVD). This polymorphism was one of the strongest predictors of death in RA (for TRAF1/C5 GG versus AA, hazard ratio 3.85 [95% confidence interval 1.18-12.59], P=0.026) alongside the erythrocyte sedimentation rate, triglyceride level, prednisolone use, and age. CONCLUSION The risk of death in RA is increased in TRAF1/C5 rs3761847 GG homozygotes and appears to be independent of RA activity and severity as well as comorbidities relevant to CVD. If this finding is replicated in future studies, TRAF1/C5 genotyping could identify patients at increased risk of death, particularly death due to malignancy or sepsis.

Transforming growth factor-β1 869T/C, but not interleukin-6 −174G/C, polymorphism associates with hypertension in rheumatoid arthritis

OBJECTIVES Part of the deleterious effects of systemic inflammation on the cardiovascular system of patients with RA may be exerted via increased propensity to hypertension. IL-6 and TGF-beta1 are important regulators of the inflammatory response. In some, but not all, studies, IL6 -174G/C (rs1800795) and TGFB1 869T/C (rs1982073) gene polymorphisms have been associated with hypertension in the general population. The present study addressed their potential association with hypertension in RA patients. METHODS TGFB1 869T/C and IL6 -174G/C were identified in 400 RA patients and 422 local, non-RA controls using real-time PCR and melting curve analysis. Binary logistic and linear regression models were used to identify the independence of the effects of the polymorphisms on hypertension. RESULTS Genotypic and allelic frequencies of the two polymorphisms were similar in RA and controls. Within the RA group, there was no significant association between IL6 -174G/C and hypertension, but TGF 869T-allele carriers had significantly increased prevalence of hypertension compared with CC homozygotes (70.2 vs 55.2%; P = 0.023). This association remained significant after adjustment for other hypertension risk factors and medication (odds ratio = 1.96; 95% CI 1.02, 3.77; P = 0.044), and was more pronounced in patients with increased systemic inflammation. CONCLUSIONS This study suggests an association of TGFB1 869T/C, but not of IL6 -174G/C, with hypertension in RA patients. If this finding is confirmed in prospective studies, this polymorphism could be used as a screening tool for RA patients with higher risk of developing hypertension and lead to increased surveillance and earlier treatment.

Anti-TNFα therapy may lead to blood pressure reductions through improved endothelium-dependent microvascular function in patients with rheumatoid arthritis

Anti-TNFα therapy may lead to blood pressure reductions through improved endothelium-dependent microvascular function in patients with rheumatoid arthritis

What predicts obesity in patients with rheumatoid arthritis? An investigation of the interactions between lifestyle and inflammation

Objective:To assess whether physical activity, diet or inflammation is a more important determinant of body mass index (BMI) and body fat (BF) in patients with rheumatoid arthritis (RA).Methods:A total of 150 RA patients (102 female) were assessed for BMI and BF. Their habitual physical activity was assessed with the international physical activity questionnaire (IPAQ) and their energy intake with a 3-day food diary. Pro-inflammatory cytokines (interleukins, IL-1 and IL-6, and tumor necrosis factor-α), erythrocyte sedimentation rate, C-reactive protein, disease activity score-28 and physical function (Health Assessment Questionnaire—HAQ) were also measured.Results:BMI correlated inversely with IPAQ (r=−0.511, P=0.000) and positively with energy intake (r=0.331, P=0.016) and HAQ (r=0.133, P=0.042). BF correlated inversely with IPAQ (r=−0.575, P=0.000) and positively with HAQ (r=0.201, P=0.037). Normal weight patients were more physically active compared with those who were either overweight (P=0.006) or obese (P=0.000). Underweight patients consumed significantly fewer calories compared with other patients (P<0.05 in all cases). Cytokines or HAQ did not differ between weight groups. IPAQ was the sole predictor of obesity, whereas energy intake was the sole predictor of underweight.Conclusions:Inflammation does not seem to influence BMI and BF in RA. As in the general population, high levels of habitual physical activity associate with low BMI and BF in RA. Energy intake is a major determinant of being underweight in those who consume fewer calories. Further research is needed to investigate the suitability of exercise and diet modalities, and their effects on the body composition of RA patients.