Inflammation, adiposity, and atherogenic dyslipidemia in rheumatoid arthritis: is there a paradoxical relationship?

Retrospective analysis and preliminary laboratory validation of treatment efficacy and blood lipid levels in patients with rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis is a systemic disease characterized by progressive chronic inflammation resulting in destruction of synovial joints. In addition to joint involvement, abnormal blood lipid indexes have also been found in RA patients. The correlation between various blood lipid indexes and the treatment effects were assessed in patients with rheumatoid arthritis, for the purposes to find a better medication strategy for RA.

METHODS

One hundred nineteen rheumatoid arthritis patients were recruited and divided into two groups, 45 patients with significant drug treatment effect and 45 patients with insignificant drug treatment effect through the nearest neighbor matching method in propensity score. The correlation between various blood lipid indexes and drug treatment effect of rheumatoid arthritis patients was analyzed. A mouse model of rheumatoid arthritis was constructed in the laboratory; methotrexate was treated as a positive drug. We observe and record the onset of rheumatoid arthritis in mice, as well as the proportion of immune cells, the expression of inflammatory factors, and the changes in blood lipid profiles was done.

RESULTS

The levels of total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), and erythrocyte sedimentation rate (ESR) in rheumatoid arthritis patients were significantly different between the two groups (P < 0.05). There was no significant difference in other indexes between the two groups (P > 0.05). Methotrexate had a good therapeutic effect on CIA model mice, and the levels of TC and HDL-C in the treatment group were higher than those in the model group.

CONCLUSION

There is a high correlation between the levels of TC and HDL-C in rheumatoid arthritis patients and the effect of drug treatment. In the clinical treatment of rheumatoid arthritis, we should focus on improving the blood lipid indexes such as TC and HDL-C, and explore more targeted individualized administration, so as to achieve better and faster treatment effect in patients with rheumatoid arthritis. Key Points • In this research, we found that the TC and HDL-C level in RA patients' blood is highly related with the therapeutic effect, and a lower level of TC and HDL-C is better for therapeutic effect of RA.

Causal relationship between PCSK9 inhibitor and autoimmune diseases: a drug target Mendelian randomization study

BACKGROUND

In addition to decreasing the level of cholesterol, proprotein convertase subtilis kexin 9 (PCSK9) inhibitor has pleiotropic effects, including immune regulation. However, the impact of PCSK9 on autoimmune diseases is controversial. Therefore, we used drug target Mendelian randomization (MR) analysis to investigate the effect of PCSK9 inhibitor on different autoimmune diseases.

METHODS

We collected single nucleotide polymorphisms (SNPs) of PCSK9 from published genome-wide association studies statistics and conducted drug target MR analysis to detect the causal relationship between PCSK9 inhibitor and the risk of autoimmune diseases. 3-Hydroxy-3-methylglutaryl-assisted enzyme A reductase (HMGCR) inhibitor, the drug target of statin, was used to compare the effect with that of PCSK9 inhibitor. With the risk of coronary heart disease as a positive control, primary outcomes included the risk of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), myasthenia gravis (MG), multiple sclerosis (MS), asthma, Crohn's disease (CD), ulcerative colitis (UC), and type 1 diabetes (T1D).

RESULTS

PCSK9 inhibitor significantly reduced the risk of SLE (OR [95%CI] = 0.47 [0.30 to 0.76], p = 1.74 × 10-3) but increased the risk of asthma (OR [95%CI] = 1.15 [1.03 to 1.29], p = 1.68 × 10-2) and CD (OR [95%CI] = 1.38 [1.05 to 1.83], p = 2.28 × 10-2). In contrast, HMGCR inhibitor increased the risk of RA (OR [95%CI] = 1.58 [1.19 to 2.11], p = 1.67 × 10-3), asthma (OR [95%CI] = 1.21 [1.04 to 1.40], p = 1.17 × 10-2), and CD (OR [95%CI] = 1.60 [1.08 to 2.39], p = 2.04 × 10-2).

CONCLUSIONS

PCSK9 inhibitor significantly reduced the risk of SLE but increased the risk of asthma and CD. In contrast, HMGCR inhibitor may be a risk factor for RA, asthma, and CD.

Exploring potential shared genetic influences between rheumatoid arthritis and blood lipid levels

BACKGROUND AND AIMS

The association between rheumatoid arthritis (RA) and blood lipid levels has often been described as paradoxical, despite the strong association between RA and cardiovascular disease (CVD) risk. We aimed to clarify the genetic architecture that would explain the relationship between RA and blood-lipid levels, while considering inflammation as measured by C-reactive protein (CRP).

METHODS

Genome-wide association study (GWAS) summary statistics were collected from the CHARGE Consortium and Global Lipids Genetics Consortium. Blood-lipid levels includes HDL-C, LDL-C, triglycerides (TG), and total cholesterol (TC). Causality was examined by assessing Mendelian Randomization (MR) analysis. Pleiotropy, the identification of shared causal variants between traits, was assessed by conducting colocalization analyses.

RESULTS

Using the MR Egger method, RA did not appear to causally predict alterations in lipid factors, rather the MR Egger intercept revealed that the genetic relationship between RA and HDL-C, LDL-C and TC may be explained by horizontal pleiotropy (p=0.003, 0.006, and 0.018, respectively). MR was suggestive of a horizontally pleiotropic relationship between CRP and lipid factors, while a causal relationship could not be ruled out. Recurring genes arising from shared causal genetic variants between RA and varying lipid factors included NAT2/PSD3, FADS2/FADS1, SH2B3, and YDJC.

CONCLUSIONS

Horizontal pleiotropy appears to explain the genetic relationship between RA and blood-lipid levels. In addition, blood-lipid levels appear to suggest a horizontally pleiotropic relationship to CRP, if not mediated through RA as well. Consideration of the pleiotropic genes between RA and blood lipid levels may aid in enhancing diagnostic means to predict CVD.

Tripterygium wilfordii glycosides ameliorates collagen-induced arthritis and aberrant lipid metabolism in rats

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease, and the dysregulation of lipid metabolism has been found to play an important role in the pathogenesis of RA and is related to the severity and prognosis of patients. Tripterygium wilfordii glycosides (TWG) is extracted from the roots of Tripterygium wilfordii Hook F. with anti-inflammatory and immunosuppressive effects, and numerous clinical trials have supported its efficacy in the treatment of RA. Some evidence suggested that TWG can modulate the formation of lipid mediators in various innate immune cells; however whether it can improve RA-related lipid disorders has not been systematically studied. In the study, type Ⅱ collagen-induced arthritis (CIA) model was used to investigate the efficacy of TWG in the treatment of RA and its effect on lipid metabolism. Paw volume, arthritis score, pathological changes of ankle joint, serum autoantibodies and inflammatory cytokines were detected to assess the therapeutic effect on arthritis in CIA rats. Then, shotgun lipidomics based on multi-dimensional mass spectrometry platform was performed to explore the alterations in serum lipidome caused by TWG. The study showed that TWG could effectively ameliorate arthritis in CIA rats, such as reducing paw volume and arthritis score, alleviating the pathological damages of joint, and preventing the production of anti-CII autoantibodies and IL-1β cytokine. Significant increase in ceramide and decrease in lysophosphatidylcholine were observed in CIA rats, and were highly correlated with arthritis score and IL-1β level. After TWG treatment, these lipid abnormalities can be corrected to a great extent. These data demonstrate that TWG exerts a beneficial therapeutic effect on aberrant lipid metabolism which may provide new insights for further exploring the role and mechanism of TWG in the treatment of RA.

Causal relationships between rheumatism and dyslipidemia: A two-sample Mendelian randomization study

BACKGROUND

Dyslipidemia is often observed in rheumatic diseases, such as ankylosing spondylitis (AS), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE), yet it remains to be detected whether rheumatic diseases have a causal effect on dyslipidemia.

METHODS

Significant (P < 5 × 10^-8) and independent (r² < 0.1) single-nucleotide polymorphisms in genome-wide association studies were selected as instrumental variables to conduct Mendelian randomization (MR) analysis. Inverse variance weighted, weighted median, and MR-Egger regression were adopted for the causal inference. Subsequently, sensitivity analysis was conducted to assess the stability and reliability of MR.

RESULTS

The MR results revealed positive causal relationships of AS with total cholesterol (TC) (β = 0.089, 95% CI = 0.050 to 0.128, P = 6.07 × 10^-6), low-density lipoprotein (LDL) (β = 0.087, 95% CI = 0.047 to 0.127, P = 1.91 × 10^-5), and high-density lipoprotein (HDL) (β = 0.043, 95% CI = 0.001 to 0.074, P = 0.009). There was no causal effect of RA on TC (β = 0.008, 95% CI = 4.86 × 10^-4 to 0.017, P = 0.064), LDL (β = 6.4 × 10^-4, 95% CI = -0.008 to 0.007, P = 0.871), or HDL (β = 0.005, 95% CI = -0.003 to 0.013, P = 0.200). Additionally, SLE had negative causal links for TC (β = -0.025, 95% CI = -0.036 to -0.015, P = 4.42 × 10^-6), LDL (β = -0.015, 95% CI = -0.025 to -0.005, P = 0.003), and HDL (β = -0.013, 95% CI = -0.021 to -0.004, P = 0.004). The results were stable and reliable.

CONCLUSION

This study suggested positive causal effects of AS on TC, LDL, and HDL and negative causal effects of SLE on these cholesterol levels, which could provide much help for the pathogenesis and treatment of rheumatic disease patients with dyslipidemia.

Vitamin Status as Predictors in Rheumatoid Arthritis

Musculoskeletal disorders are the leading cause of long term disability in EU with a significant impact on health care system and with increased social and economic costs. Despite of recent advances in Rheumatoid arthritis (RA) research field, here is still lacking of specific biomarkers that can be used in order to distinguish between different RA patterns and the clinical criteria are still the main tool used only for classification of diseases. Our hypothesis is that the vitamin deficiency associated with chronic inflammation can lead to a mild increase in Hcy level in blood that can act as predictor of increased risk of complication in RA patients. The aim of our study was to identify a correlation between level of Hcy in peripheral blood samples collected from RA patients and to establish if the Hcy level can be validate as potential predictive biomarker in RA patients treated with different DMARDs. Our findings suggest that Hcy level in plasma and CRP are independent predictors of chronic inflammatory status and are useful biomarkers in order to estimate the risk of complication in RA patients. To our knowledge to date, studies before had a controversial findings regarding the efficiency of folate and B12 vitamins supplements on decreasing the cardiovascular events risk. We showed that the folic acid and B12 supplements are important.

A new alkaloid from Portulaca oleracea L. and its anti-inflammatory activity

A new alkaloid, identified as (E)-2-(4-hydroxyphenyl)-3-(pyridazin-3-yl)-acrylaldehyde, named oleradazine, was isolated from Portulaca oleracea L., and the structure was elucidated using spectroscopic methods, including 1D and 2D NMR spectroscopic and UHPLC-ESI-QTOF/MS methods. In addition, the compound was used to investigate its anti-inflammatory activity in lipopolysaccharide-stimulated macrophages. It was suggested that the oleradazine can significantly inhibit the inflammatory factors, interleukin 1β and nitric oxide in lipopolysaccharide-stimulated RAW 264.7 cells by enzyme-linked immunosorbent assays.

Albumin/Globulin Ratio as Yin-Yang in Rheumatoid Arthritis and Its Correlation to Inflamm-Aging Cytokines

Purpose

Inflamm-aging is a novel-concept in rheumatoid arthritis (RA) with accelerating aging process. We try to find a correlation between serum albumin/globulin (A/G) ratio and clinical biochemical parameters, incidence of aging-related diseases (ARDs) as well as inflammaging-related molecules.

Patients and Methods

Healthy controls (HC) and RA patients were compared with their clinical biochemical parameters including albumin and globulin levels, A/G ratio, and levels of serum lipids. Incidence of ARDs in RA was compared with A/G ratio, having a cut off value of 1.2. Expression levels of leptin and Trf2 genes in PBMCs, and inflammatory factors like IL-1β, IL-6, IL-8 and TNF-ɑ between HC and RA patients were compared, and correlated with the A/G ratio.

Results

Compared to HC, RA patients had decreased levels of albumin, while globulin levels were found to be increased, which led to a significantly lower A/G ratio in RA patients. A/G ratio rather than ESR and CRP had significant correlation with dyslipidemia in RA patients. Patients with A/G <1.2 had a higher risk of ARDs than patients with A/G >1.2. The RR was 2.48 (95% CI: 1.79 to 3.64, p <0.0001). In addition, A/G ratio has positively correlated to leptin and Trf2 expression, while an inverse correlation was observed with the levels of inflamm-aging related cytokines like IL-6, IL-8 and TNF-ɑ.

Conclusion

A decreased A/G ratio in RA patients has significantly correlated with dyslipidemia and ARDs, as well as inflammaging- related adipokine and pro-inflammatory cytokines. Thus, A/G ratio could be a reliable marker for evaluating the inflammaging process during clinical management in ARDs.

Evaluation of dysfunctional high-density lipoprotein levels with myeloperoxidase/paraoxonase-1 ratio in rheumatoid arthritis

BACKGROUND

The aim of this study is to evaluate dysfunctional high-density lipoprotein cholesterol (HDL) by measuring myeloperoxidase (MPO)/paraoxonase 1 (PON1) ratio in patients with rheumatoid arthritis (RA) and to investigate the relationship between dysfunctional HDL and cardiovascular disease (CVD) in RA patients.

METHODS

Sixty-seven healthy individuals and 130 RA patients were included in the study. Routine lipid panels (triglyceride (TG), low-density lipoprotein cholesterol (LDL), HDL, total cholesterol (TC), PON1 and MPO levels were measured. Disease activity scores-28 (DAS28) of RA patients were calculated. Cardiological examination records of the patients were assessed to detect patients who also have CVD.

RESULTS

There were no significant differences between RA and control groups in routine lipid profiles (P > .05 for all). MPO/PON1 ratios were significantly elevated in the RA group compared with the control group (P < .001). MPO/PON1 ratios were higher in RA patients with CVD history compared with those without CVD (P < .05). MPO/PON1 ratios were correlated with DAS28 scores (rho: 0.357, P < .001).

CONCLUSION

HDL dysfunction determined by the MPO/PON1 ratio may be associated with the pathophysiology of increased CVD in RA. Thus, evaluating dysfunctional HDL levels by measuring the MPO/PON1 ratio in RA patients may allow more detailed patient follow-up, as well as the reduction of CVD events in RA patients with therapeutic agents aiming to increase the functional properties of HDL by decreasing this ratio.

Skeletal muscle disease in rheumatoid arthritis: the center of cardiometabolic comorbidities?

PURPOSE OF REVIEW

Despite its critical roles in body movement, structure, and metabolism, skeletal muscle remains underappreciated in the context of rheumatoid arthritis. In rheumatoid arthritis, chronic inflammation, physical inactivity, and medication toxicities impair skeletal muscle. These skeletal muscle alterations contribute to continued rheumatoid arthritis disparities in physical function and cardiometabolic health.

RECENT FINDINGS

In the prebiologic disease-modifying antirheumatic drug era, rheumatoid arthritis skeletal muscle atrophy was the central feature of 'rheumatoid cachexia,' a hypermetabolic state driven by chronic systemic inflammation and muscle protein degradation. In the current era, rheumatoid arthritis muscle deficits are less visible, yet persist as a key component of 'sarcopenic obesity.' In rheumatoid arthritis sarcopenic obesity, chronic inflammation, physical inactivity, and medication toxicities contribute to muscle contractile deficits, inflammation, altered metabolism, and intramuscular adiposity, a key predictor of rheumatoid arthritis disability and insulin resistance.

SUMMARY

Rheumatoid arthritis skeletal muscle disease in the current era is defined by impaired contractile function (poor strength and endurance) and sarcopenic obesity (decreased muscle mass, increased fat mass, and intramuscular adiposity). These muscle impairments contribute to disability and cardiometabolic disease in rheumatoid arthritis. Management should focus on monitoring of rheumatoid arthritis muscle function and body composition, limiting potentially myotoxic drugs, and prescription of exercise training.

Medical Compliance of Fibrate and the Decreased Risk of Age-Related Macular Degeneration in Dyslipidemia-Related Diseases: A Population-Based Cohort Study

The purpose of the current study is to evaluate the incidence of age-related macular degeneration (AMD) in dyslipidemia-related diseases with or without the use of fibrate. Patients were defined as dyslipidemia-related diseases according to the diagnostic code and lab exam arrangement, then the population was divided into those with fibrate application and those without via 1:2 ratios of propensity-score matching. The primary outcome is the development of AMD after dyslipidemia-related diseases by the Cox proportional hazard regression. Besides, the relationship between the medical compliance of fibrate, presented as medical possession ratio (MPR), and the AMD development was also analyzed. A total of 22,917 patients and 45,834 individuals were enrolled in the study and control groups. There were 572 and 1181 events of any AMD development in the study and control groups which showed identical risk of AMD (aHR: 0.94, 95% CI: 0.85–1.04). However, a reduced risk of any AMD was found in those patients reached a baseline MPR more than 20% (aHR: 0.729, 95% CI: 0.599–0.887, p = 0.0016) and overall MPR more than 5% three years after the diagnosis of dyslipidemia-related diseases (aHR: 0.712, 95% CI: 0.557–0.909, p = 0.0065). Besides, a lower risk of dry-AMD was also found in those patients with the above conditions (aHR: 0.736, 95% CI: 0.599–0.906, p = 0.0038 and aHR: 0.721, 95% CI: 0.557–0.934, p = 0.0133, respectively). In conclusion, the use of fibrate with fair initial medical compliance will decrease the incidence of AMD in patients with dyslipidemia-related diseases, especially for the development of dry-AMD.

Insights in the Role of Lipids, Oxidative Stress and Inflammation in Rheumatoid Arthritis Unveiled by New Trends in Lipidomic Investigations

Rheumatoid arthritis (RA) is a highly debilitating chronic inflammatory autoimmune disease most prevalent in women. The true etiology of this disease is complex, multifactorial, and is yet to be completely elucidated. However, oxidative stress and lipid peroxidation are associated with the development and pathogenesis of RA. In this case, oxidative damage biomarkers have been found to be significantly higher in RA patients, associated with the oxidation of biomolecules and the stimulation of inflammatory responses. Lipid peroxidation is one of the major consequences of oxidative stress, with the formation of deleterious lipid hydroperoxides and electrophilic reactive lipid species. Additionally, changes in the lipoprotein profile seem to be common in RA, contributing to cardiovascular diseases and a chronic inflammatory environment. Nevertheless, changes in the lipid profile at a molecular level in RA are still poorly understood. Therefore, the goal of this review was to gather all the information regarding lipid alterations in RA analyzed by mass spectrometry. Studies on the variation of lipid profile in RA using lipidomics showed that fatty acid and phospholipid metabolisms, especially in phosphatidylcholine and phosphatidylethanolamine, are affected in this disease. These promising results could lead to the discovery of new diagnostic lipid biomarkers for early diagnosis of RA and targets for personalized medicine.

GlycA measured by NMR spectroscopy is associated with disease activity and cardiovascular disease risk in chronic inflammatory diseases

GlycA is a biomarker of systemic inflammation, quantifying both the protein concentrations and glycosylation states of several acute phase proteins. GlycA has been shown to be associated with both subclinical atherosclerosis and with cardiovascular disease (CVD). GlycA levels are higher in acute and chronic inflammation. During ongoing systemic inflammatory processes, GlycA specific acute phase reactants and proteins undergo circulating concentration and glycosylation pattern changes, and these alterations are reflected in the GlycA NMR signal. Additionally, levels associate with ongoing disease severity in individuals with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and psoriasis thus capturing active inflammation. Furthermore, in these disease states, GlycA is associated with cardiovascular disease (CVD) independent of traditional risk factors including C-reactive protein (CRP). Finally, GlycA levels decrease with exercise, weight loss, and systemic anti-inflammatory agents. Therefore, GlycA appears to be a promising new composite biomarker of active systemic inflammation including assessing CVD risk in patients with inflammatory diseases.

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Patients with chronic inflammatory disorders are at increased risk for cardiovascular diseasenot captured by traditional risk factors.

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GlycA is a biomarker of acute phase reactants by NMR spectroscopy which captures disease activity in human inflammatory diseases.

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GlycA associates with cardiovascular disease and offers a tool to monitor primary disease activity and assess CVD risk in inflammatory diseases.

Cardiovascular risk in persons at risk of developing rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is associated with an increased cardiovascular disease (CVD) risk which may start even before diagnosis. To explore this CVD risk prior to RA, we determined multiple risk factors and two 10-year clinical risk scores in a cohort of individuals at-risk of RA. We also analyzed associations with arthritis development and autoantibody status and compared a subset of at-risk individuals to an age and sex matched seronegative control group.

Methods

In a cohort of 555 consecutive arthralgia patients positive for rheumatoid factor (RF) and / or anti-citrullinated protein antibody (ACPA) we retrospectively identified patients with preclinical arthritis (i.e. those who developed arthritis), and non-arthritis patients (those without arthritis development during maximum 5 years follow up). Demographics, CVD risk factors and the 10-year cardiovascular risk according to the SCORE and QRISK3 system were determined at baseline.

Results

Preclinical arthritis patients (n = 188) had a higher heart rate (68 vs 63 bpm, p = 0.048) and lower cholesterol (5.2 mmol/l vs 5.5, p = 0.006), HDL (1.0 mmol/l vs 1.1, p0.003) and ApoB (0.85 g/l vs 0.91, p = 0.011) compared to non-arthritis patients (n = 367). Lipid levels were associated with ACPA status in both the preclinical arthritis and non-arthritis group. Ten-year CVD risk scores did not differ between preclinical arthritis and non-arthritis patients, in total, 7% (SCORE) and 8% (QRISK3) of seropositive arthralgia patients were classified as high risk. Seropositive at-risk patients (n = 71) had higher total cholesterol (5.4 vs 4.9, p<0.001), TC/HDL ratio (4.0 vs 3.0, p<0.001), triglycerides (1.4 vs 1.0, p = 0.001), ApoB (1.0 vs 0.9, p = 0.019) and 10-year risk scores (median SCORE 1.0 vs 0.0, p = 0.030 and median QRISK3 4.4 vs 3.1, p<0.001) compared to seronegative controls.

Conclusion

Our results suggest that lipid changes commence prior to RA diagnosis and that ACPAs might play a role.

High density lipoprotein in rheumatoid arthritis: emerging role in predicting inflammation level and osteoporosis occurrence

Dyslipidaemia is common in patients with rheumatoid arthritis (RA) appearing both early and advanced stages of the disease. A retrospective study was designed to explore the clinical significance of high density lipoprotein (HDL) in Chinese patients with RA. Serum levels of total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL) and low density lipoprotein (LDL) were compared between RA patients complicated with osteoporosis (OP) and without OP, using logistic regression and ROC curve to analyse the association of HDL with OP. C reactive protein (CRP), erythrocyte sedimentation rate(ESR), rheumatoid factor(RF), anti-cyclic citrulline polypeptide antibody (anti-CCP), 28 joints disease activity(DAS28) as well as organ involvement rates were then analysed between RA patients with different HDL levels. Serum levels of HDL were 1.2 ± 0.3 mmol/L in RA patients complicated with OP, significantly higher than those without OP; HDL was a risk factor for RA patients with OP, OR (95% CI) being 10.2 (4.5-23.0) after adjusting for gender, age and body mass index(BMI). RA patients with HDL ≤ 1.04 mmol/L had significantly higher levels of CRP, ESR, DAS28 and cardiovascular disease (CVD) incidence rate, yet OP incidence rate was lower. HDL was a predictor of RA-related OP, indicating potential value as predictor of disease complications in RA patients.

Cardiovascular Risk Assessment and Therapeutic Implications in Rheumatoid Arthritis

Patients with rheumatoid arthritis (RA) suffer from a magnitude of excess cardiovascular risk. A paradoxical lipid pattern has been observed in rheumatoid arthritis patients where low levels of total cholesterol and low-density lipoprotein are associated with a higher risk of cardiovascular disease. This paper aims to break down the evidence explaining why patients with low to normal LDL, and total cholesterol have such excess cardiovascular risk. A component of the enhanced cardiovascular risk is systemic inflammation and the subsequent pro-atherogenic dyslipidemia patterns. Due to this "lipid paradox," current risk algorithms and guidelines designed for the general population may underestimate cardiovascular risk in patients with rheumatoid arthritis. The purpose of this paper is to critically evaluate some of the discrepancies and layers of cardiovascular risk in RA patients, the role RA medication may have in mitigating or increasing cardiovascular risk, and the possible role of statin therapy.

High LDL levels lessen bone destruction during antigen-induced arthritis by inhibiting osteoclast formation and function

Rheumatoid arthritis (RA) is a chronic inflammatory disease, characterized by severe joint inflammation and bone destruction as the result of increased numbers and activity of osteoclasts. RA is often associated with metabolic syndrome, whereby elevated levels of LDL are oxidized into oxLDL, which might affect osteoclastogenesis. In this study, we induced antigen-induced arthritis (AIA) in Apoe^-/- mice, which spontaneously develop high LDL levels, to investigate the effects of high LDL/oxLDL levels on osteoclast differentiation and bone destruction. Whereas basal levels of bone resorption were comparable between naive WT and Apoe^-/- mice, induction of AIA resulted in a significant reduction of bone destruction in Apoe^-/- mice as compared to WT controls. In line with that, the TRAP⁺ area on the cortical bone was significantly decreased. The absence of Apoe did affect neither the numbers of CD11b⁺Ly6C^high and CD11b^-/Ly6C^high osteoclast precursors (OCPs) in the BM of naïve mice nor their in vitro osteoclastogenic potential as indicated by comparable mRNA expression of osteoclast markers. Addition of oxLDL, but not LDL, to pre-osteoclasts from day 3 and mature osteoclasts from day 6 of osteoclastogenesis strongly reduced the number of TRAP⁺ osteoclasts and their resorptive capacity. This coincided with a decreased expression of various osteoclast markers. Interestingly, oxLDL significantly lowered the expression of osteoclast-associated receptor (Oscar) and the DNAX adaptor protein-12 encoding gene Tyrobp, which regulate the immunoreceptor tyrosine-based activation motif (ITAM) co-stimulation pathway that is strongly involved in osteoclastogenesis. Collectively, our findings suggest that under inflammatory conditions in the joint, high LDL levels lessen bone destruction during AIA, probably by formation of oxLDL that inhibits osteoclast formation and activity through modulation of the ITAM-signaling.

Modelling disease risk for amyloid A (AA) amyloidosis in non-human primates using machine learning

Objective: Amyloid A (AA) amyloidosis is found in humans and non-human primates, but quantifying disease risk prior to clinical symptoms is challenging. We applied machine learning to identify the best predictors of amyloidosis in rhesus macaques from available clinical and pathology records. To explore potential biomarkers, we also assessed whether changes in circulating serum amyloid A (SAA) or lipoprotein profiles accompany the disease. Methods: We conducted a retrospective study using 86 cases and 163 controls matched for age and sex. We performed data reduction on 62 clinical, pathological and demographic variables, and applied multivariate modelling and model selection with cross-validation. To test the performance of our final model, we applied it to a replication cohort of 2,775 macaques. Results: The strongest predictors of disease were colitis, gastrointestinal adenocarcinoma, endometriosis, arthritis, trauma, diarrhoea and number of pregnancies. Sensitivity and specificity of the risk model were predicted to be 82%, and were assessed at 79 and 72%, respectively. Total, low density lipoprotein and high density lipoprotein cholesterol levels were significantly lower, and SAA levels and triglyceride-to-HDL ratios were significantly higher in cases versus controls. Conclusion: Machine learning is a powerful approach to identifying macaques at risk of AA amyloidosis, which is accompanied by increased circulating SAA and altered lipoprotein profiles.

Lipid management in rheumatoid arthritis: a position paper of the Working Group on Cardiovascular Pharmacotherapy of the European Society of Cardiology

Rheumatoid arthritis (RA) is associated with increased cardiovascular morbidity, partly due to alterations in lipoprotein quantity, quality and cell cholesterol trafficking. Although cardiovascular disease significantly contributes to mortality excess in RA, cardiovascular prevention has been largely insufficient. Because of limited evidence, optimal strategies for lipid management (LM) in RA have not been determined yet, and recommendations are largely based on expert opinions. In this position paper, we describe abnormalities in lipid metabolism and introduce a new algorithm for estimation of cardiovascular risk (CVR) and LM in RA. The algorithm stratifies patients according to RA-related factors impacting CVR (such as RA activity and severity and medication). We propose strategies for monitoring of lipid parameters and treatment of dyslipidaemia in RA (including lifestyle, statins and other lipid-modifying therapies, and disease modifying antirheumatic drugs). These opinion-based recommendations are meant to facilitate LM in RA until more evidence is available.

Perspective: The Dietary Inflammatory Index (DII)-Lessons Learned, Improvements Made, and Future Directions

The literature on the role of inflammation in health has grown exponentially over the past several decades. Paralleling this growth has been an equally intense focus on the role of diet in modulating inflammation, with a doubling in the size of the literature approximately every 4 y. The Dietary Inflammatory Index (DII) was developed to provide a quantitative means for assessing the role of diet in relation to health outcomes ranging from blood concentrations of inflammatory cytokines to chronic diseases. Based on literature from a variety of different study designs ranging from cell culture to observational and experimental studies in humans, the DII was designed to be universally applicable across all human studies with adequate dietary assessment. Over the past 4 y, the DII has been used in >200 studies and forms the basis for 12 meta-analyses. In the process of conducting this work, lessons were learned with regard to methodologic issues related to total energy and nutrient intake and energy and nutrient densities. Accordingly, refinements to the original algorithm have been made. In this article we discuss these improvements and observations that we made with regard to misuse and misinterpretation of the DII and provide suggestions for future developments.

Hashimoto Thyroiditis and Dyslipidemia in Childhood: A Review

Hashimoto autoimmune thyroiditis (AIT) is the most common cause of acquired hypothyroidism in the pediatric population. Development of AIT is mediated mainly by cellular immune response directed toward thyroid autoantigens, leading to inflammation and impaired function of thyroid gland. Both thyroid dysfunction and inflammation affect the metabolism of plasma lipoproteins. The alterations in lipid profile worsen with the advancement of hypothyroidism, ranging from discrete changes in euthyroid AIT patients, to atherogenic dyslipidemia in the overt hypothyroidism. In this review, characteristics of dyslipidemia in pediatric AIT patients, and the consequences in respect to the risk for cardiovascular disease (CVD) development are discussed. Additionally, benefit of L-thyroxine treatment on serum lipid profile in pediatric AIT patients is addressed. Finally, potential usefulness of novel lipid biomarkers, such as proprotein convertase subtilisin/kexin type 9 (PCSK9), non-cholesterol sterols, low-density lipoprotein particle size and number, and high-density lipoprotein structure and functionality in AIT patients is also covered. Further longitudinal studies are needed in order to elucidate the long-term cardiovascular outcomes of dyslipidemia in pediatric patients with Hashimoto AIT.

The changes of immunoglobulin G N-glycosylation in blood lipids and dyslipidaemia

BACKGROUND

Alternative N-glycosylation has significant structural and functional consequences on immunoglobulin G (IgG) and can affect immune responses, acting as a switch between pro- and anti-inflammatory IgG functionality. Studies have demonstrated that IgG N-glycosylation is associated with ageing, body mass index, type 2 diabetes and hypertension.

METHODS

Herein, we have demonstrated patterns of IgG glycosylation that are associated with blood lipids in a cross-sectional study including 598 Han Chinese aged 20-68 years. The IgG glycome composition was analysed by ultra-performance liquid chromatography.

RESULTS

Blood lipids were positively correlated with glycan peak GP6, whereas they were negatively correlated with GP18 (P < 0.05/57). The canonical correlation analysis indicated that initial N-glycan structures, including GP4, GP6, GP9-12, GP14, GP17, GP18 and GP23, were significantly correlated with blood lipids, including total cholesterol, total triglycerides (TG) and low-density lipoprotein (r = 0.390, P < 0.001). IgG glycans patterns were able to distinguish patients with dyslipidaemia from the controls, with an area under the curve of 0.692 (95% confidence interval 0.644-0.740).

CONCLUSIONS

Our findings indicated that a possible association between blood lipids and the observed loss of galactose and sialic acid, as well as the addition of bisecting GlcNAcs, which might be related to the chronic inflammation accompanying with the development and procession of dyslipidaemia.

GlycA, a novel biomarker of systemic inflammation and cardiovascular disease risk

Background

GlycA is a novel spectroscopic marker of systemic inflammation with low intra-individual variability and other attributes favoring its clinical use in patients with chronic inflammatory and autoimmune diseases. GlycA is unique in its composite nature, reflecting both increased glycan complexity and circulating acute phase protein levels during local and systemic inflammation. Recent studies of GlycA from cross-sectional, observational and interventional studies have been highly informative, demonstrating that GlycA is elevated in acute and chronic inflammation, predicts death in healthy individuals and is associated with disease severity in patients with chronic inflammatory diseases such as rheumatoid arthritis, psoriasis and lupus. Moreover, following treatment with biological therapy in psoriasis, reduction in skin disease severity was accompanied by a decrease in GlycA levels and improvement in vascular inflammation.

Conclusions

Collectively, these findings suggest GlycA is a marker that tracks systemic inflammation and subclinical vascular inflammation. However, larger prospective studies and randomized trials are necessary in order to assess the impact of novel therapies on GlycA in patients with chronic inflammatory conditions, which may be concomitant with cardiovascular benefits.

Tofacitinib restores the inhibition of reverse cholesterol transport induced by inflammation: understanding the lipid paradox associated with rheumatoid arthritis

BACKGROUND AND PURPOSE

Patients with active rheumatoid arthritis (RA) have increased cardiovascular mortality, paradoxically associated with reduced circulating lipid levels. The JAK inhibitor tofacitinib ameliorates systemic and joint inflammation in RA with a concomitant increase in serum lipids. We analysed the effect of tofacitinib on the lipid profile of hyperlipidaemic rabbits with chronic arthritis (CA) and on the changes in reverse cholesterol transport (RCT) during chronic inflammation.

EXPERIMENTAL APPROACH

CA was induced in previously immunized rabbits, fed a high-fat diet, by administering four intra-articular injections of ovalbumin. A group of rabbits received tofacitinib (10 mg·kg-1 ·day-1 ) for 2 weeks. Systemic and synovial inflammation and lipid content were evaluated. For in vitro studies, THP-1-derived macrophages were exposed to high lipid concentrations and then stimulated with IFNγ in the presence or absence of tofacitinib in order to study mediators of RCT.

KEY RESULTS

Tofacitinib decreased systemic and synovial inflammation and increased circulating lipid levels. Although it did not modify synovial macrophage density, it reduced the lipid content within synovial macrophages. In foam macrophages in culture, IFNγ further stimulated intracellular lipid accumulation, while the JAK/STAT inhibition provoked by tofacitinib induced lipid release by increasing the levels of cellular liver X receptor α and ATP-binding cassette transporter (ABCA1) synthesis.

CONCLUSIONS AND IMPLICATIONS

Active inflammation could be associated with lipid accumulation within macrophages of CA rabbits. JAK inhibition induced lipid release through RCT activation, providing a plausible explanation for the effect of tofacitinib on the lipid profile of RA patients.

Distinct Secretory Activity and Clinical Impact of Subcutaneous Abdominal Adipose Tissue in Women with Rheumatoid Arthritis and Osteoarthritis

In the general population, low-grade inflammation of adipose tissue accompanies obesity and contributes to cardiovascular disease (CVD) development, but the implication of this tissue in rheumatic disease pathology is unclear. Therefore, we characterized the secretory activity of subcutaneous abdominal adipose tissue (SAAT) of females with rheumatoid arthritis (RA) and osteoarthritis (OA) and searched for its relationship with intensity of systemic inflammation, body composition and comorbidity. The secretion of classical adipokines (leptin, adiponectin), pro- and anti-inflammatory factors, i.e. interleukin (IL)-6, IL-8, IL-10, tumour necrosis factor (TNF), macrophage migration inhibitory factor (MIF) and hepatocyte growth factor (HGF), from SAAT explants was measured by specific enzyme-linked immunosorbent assays. Patients' body composition was evaluated by bioelectric impendence technique. Rheumatoid SAAT secreted more adiponectin, IL-6, IL-10, TNF and MIF but less leptin than respective osteoarthritis tissues. In RA patients, TNF secretion correlated with cachectic body composition, HGF release was linked to secondary amyloidosis and visceral fat rating was an independent risk factor for CVD. In OA, secretion of leptin and HGF positively, while adiponectin inversely, correlated with systemic inflammation markers, and the release of MIF was an independent risk factor for CVD. This study reveals differences between RA and OA patients in SAAT secretory activity and suggests its different clinical impact in these diseases, characterized by high- and low-grade systemic inflammation, respectively. In RA, SAAT may directly or via an effect on body composition contribute to amyloidosis, cachexia or CVD co-occurring, while in OA SAAT-derived adipocytokines may rather regulate intensity of systemic inflammation and redound to CVD emergence.

Does a lack of physical activity explain the rheumatoid arthritis lipid profile?

Background

In rheumatoid arthritis (RA), cardiovascular risk is associated with paradoxical reductions in total cholesterol, low density lipoprotein-cholesterol (LDL-C), and high density lipoprotein-cholesterol (HDL-C). Concentrations of small LDL (LDL-P) and HDL (HDL-P) particles are also reduced with increased inflammation and disease activity in RA patients. Here we sought to identify which measure(s) of inflammation, disease activity and cardiometabolic risk contribute most to the RA-associated lipoprotein profile.

Methods

NMR lipoprotein measurements were obtained for individuals with RA (n = 50) and age-, gender-, and body mass index (BMI)-matched controls (n = 39). Groups were compared using 39 matched pairs with 11 additional subjects used in RA only analyses. Among RA patients, relationships were determined for lipoprotein parameters with measures of disease activity, disability, pain, inflammation, body composition, insulin sensitivity and exercise. Percentage of time spent in basal activity (<1 metabolic equivalent) and exercise (≥3 metabolic equivalents) were objectively-determined.

Results

Subjects with RA had fewer total and small LDL-P as well as larger LDL and HDL size (P < 0.05). Among RA patients, pain and disability were associated with fewer small HDL-P (P < 0.05), while interleukin (IL)-6, IL-18, and TNF-α were associated with LDL size (P < 0.05). BMI, waist circumference, abdominal visceral adiposity and insulin resistance were associated with more total and small LDL-P, fewer large HDL-P, and a reduction in HDL size (P < 0.05). Most similar to the RA lipoprotein profile, more basal activity (minimal physical activity) and less exercise time were associated with fewer small LDL-P and total and small HDL-P (P < 0.05).

Conclusions

The RA-associated lipoprotein profile is associated with a lack of physical activity.

As this was a cross-sectional investigation and not an intervention and was performed from 2008–13, this study was not registered in clinicaltrials.gov.

Modulation of autoimmune arthritis severity in mice by apolipoprotein E (ApoE) and cholesterol

Apolipoprotein E (ApoE) deficiency promoted an exacerbation of autoimmune arthritis in mice by inducing proinflammatory immune responses. In this study we analysed the contribution of hypercholesterolaemia and/or the absence of ApoE anti-inflammatory properties, unrelated to its function in the control of cholesterol metabolism, towards the acceleration of arthritis in these mutant animals. The induction and severity of collagen type II-induced arthritis (CIA) were compared for B10.RIII wild-type (WT), B10.RIII.ApoE^+/- , B10.RIII.ApoE^-/- and B10.RIII.low-density lipoprotein receptor (LDLR^-/- ) mice with different concentrations of circulating ApoE and cholesterol. A 50-70% reduction in serum levels of ApoE was observed in heterozygous B10.RIII.ApoE^+/- mice in comparison to B10.RIII.WT, although both strains of mice exhibited similar circulating lipid profiles. This ApoE reduction was associated with an increased CIA severity that remained lower than in homozygous B10.RIII.ApoE^-/- mice. An important rise in circulating ApoE concentration was observed in hypercholesterolaemic B10.RIII.LDLR^-/- mice fed with a normal chow diet, and both parameters increased further with an atherogenic hypercholesterolaemic diet. However, the severity of CIA in B10.RIII.LDLR^-/- mice was similar to that of B10.RIII.WT controls. In conclusion, by comparing the evolution of CIA between several strains of mutant mice with different levels of serum ApoE and cholesterol, our results demonstrate that both hypercholesterolaemia and ApoE regulate the intensity of in-vivo systemic autoimmune responses.

Three Novel Alkaloids from Portulaca oleracea L. and Their Anti-inflammatory Effects

Three novel carbon skeleton alkaloids, named oleracimine (1), oleracimine A (2), and oleracone A (3), with one novel azulene carbon skeleton compound, oleracone B (4), and one known compound, β-carboline (5), were first isolated from Portulaca oleracea L. The structures were determined using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance and high-resolution electrospray ionization time-of-flight mass spectrometry techniques. In addition, oleracimine (1) was used to investigate the anti-inflammatory effects on lipopolysaccharide-stimulated macrophages. The results of enzyme-linked immunosorbent assay, western blot, and real-time polymerase chain reaction showed that oleracimine (1) remarkably inhibited nitric oxide production and could dose-dependently decrease the secretions of interleukin 6, tumor necrosis factor α, nitric oxide, and prostaglandin E2 in cell culture supernatants as well as the mRNA of cyclooxygenase-2 and inducible nitric oxide synthase.

Inflammatory glycoproteins in cardiometabolic disorders, autoimmune diseases and cancer

The physiological function initially attributed to the oligosaccharide moieties or glycans on inflammatory glycoproteins was to improve protein stability. However, it is now clear that glycans play a prominent role in glycoprotein structure and function and in some cases contribute to disease states. In fact, glycan processing contributes to pathogenicity not only in autoimmune disorders but also in atherosclerotic cardiovascular disease, diabetes and malignancy. While most clinical laboratory tests measure circulating levels of inflammatory proteins, newly developed diagnostic and prognostic tests are harvesting the information that can be gleaned by measuring the amount or structure of the attached glycans, which may be unique to individuals as well as various diseases. As such, these newer glycan-based tests may provide future means for more personalized approaches to patient stratification and improved patient care. Here we will discuss recent progress in high-throughput laboratory methods for glycomics (i.e. the study of glycan structures) and glycoprotein quantification by methods such as mass spectrometry and nuclear magnetic resonance spectroscopy. We will also review the clinical utility of glycoprotein and glycan measurements in the prediction of common low-grade inflammatory disorders including cardiovascular disease, diabetes and cancer, as well as for monitoring autoimmune disease activity.

Z-guggulsterone negatively controls microglia-mediated neuroinflammation via blocking IκB-α-NF-κB signals

Induction of pro-inflammatory factors is one of the characteristics of microglial activation and can be regulated by numerous active agents extracted from plants. Suppression of pro-inflammatory factors is beneficial to alleviate neuroinflammation. Z-guggulsterone, a compound extracted from the gum resin of the tree commiphora mukul, exhibits numerous anti-inflammatory effects. However, the role and mechanism of Z-guggulsterone in pro-inflammatory responses in microglia remains unclear. This study addressed this issue in in vitro murine microglia and in vivo neuroinflammation models. Results showed that Z-guggulsterone reduced inducible nitric oxide (iNOS) protein expression as well as nitric oxide (NO), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) production in LPS-stimulated BV-2 cells. Z-guggulsterone also reduced the mRNA level of iNOS, TNF-α, and IL-6. Mechanistic studies revealed that Z-guggulsterone attenuated the LPS-induced degradation of inhibitor κ B-α (IκB-α) as well as the LPS-induced nuclear translocation of nuclear factor-κB (NF-κB). Z-guggulsterone, however, failed to reduce the LPS-induced increase in NF-κB phosphorylation level. These major findings were ascertained in primary microglia where the LPS-induced increases in iNOS expression, NO content, and IκB-α degradation were diminished by Z-guggulsterone treatment. In a mouse model of neuroinflammation, Z-guggulsterone exhibited significant anti-inflammatory effects, which were exemplified by the attenuation of microglial activation and neuroinflammation-induced behavioral abnormalities in Z-guggulsterone-treated mice. Taken together, these studies demonstrate that Z-guggulsterone attenuates the LPS-mediated induction of pro-inflammatory factors in microglia via inhibition of IκB-α-NF-κB signals, providing evidence to uncover the potential role of Z-guggulsterone in neuroinflammation-associated disorder therapies.

Association between osteoarthritis and cardiovascular disease: Systematic review and meta-analysis

BACKGROUND

To examine for a possible relationship between osteoarthritis and cardiovascular disease.

DESIGN

A systematic review and meta-analysis.

METHODS

Published and unpublished literature from: MEDLINE, EMBASE, CINAHL, the Cochrane Library, OpenGrey and clinical trial registers. Search to 22 November 2014. Cohort, case-control, randomised and non-randomised controlled trial papers reporting the prevalence of cardiovascular disease in osteoarthritis were included.

RESULTS

Fifteen studies with 32,278,744 individuals were eligible. Pooled prevalence for overall cardiovascular disease pathology in people with osteoarthritis was 38.4% (95% confidence interval (CI): 37.2% to 39.6%). Individuals with osteoarthritis were almost three times as likely to have heart failure (relative risk (RR): 2.80; 95% CI: 2.25 to 3.49) or ischaemic heart disease (RR: 1.78; 95% CI: 1.18 to 2.69) compared with matched non-osteoarthritis cohorts. No significant difference was detected between the two groups for the risk of experiencing myocardial infarction or stroke. There was a three-fold decrease in the risk of experiencing a transient ischaemic attack in the osteoarthritis cohort compared with the non-osteoarthritis group.

CONCLUSIONS

Prevalence of cardiovascular disease in patients with osteoarthritis is significant. There was an observed increased risk of incident heart failure and ischaemic heart disease in people with osteoarthritis compared with matched controls. However, the relationship between osteoarthritis and cardiovascular disease is not straightforward and there is a need to better understand the potential common pathways linking pathophysiological mechanisms.