Apolipoprotein A-I-dependent cholesterol esterification in patients with rheumatoid arthritis

Subclinical atherosclerosis in patients with rheumatoid arthritis

We performed a systematic review with meta-analysis and meta-regression of literature studies evaluating the impact of rheumatoid arthritis (RA) on common carotid artery intima-media thickness (CCAIMT) and on the prevalence of carotid plaques. Studies evaluating the relationship between RA and markers of cardiovascular (CV) risk (CCA-IMT and prevalence of carotid plaques) were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. A total of 59 studies (4,317 RA patients and 3,606 controls) were included in the final analysis, 51 studies with data on CCA-IMT (52 data-sets on 3,600 RA patients and 3,020 controls) and 35 studies reporting on the prevalence of carotid plaques (2,859 RA patients and 2,303 controls). As compared to controls, RA patients showed a higher CCA-IMT (mean difference [MD]: 0.10 mm; 95 % confidence interval [CI]: 0.07, 0.12; p < 0.00001), and an increased prevalence of carotid plaques (odds ratio [OR]: 3.61; 95 %CI: 2.65, 4.93; p< 0.00001). Interestingly, when analysing studies on early RA, the difference in CCAIMT among RA patients and controls was even higher (MD: 0.21 mm; 95 %CI: 0.06, 0.35; p=0.006), and difference in the prevalence of carotid plaques was entirely confirmed (OR: 3.57; 95 %CI: 1.69, 7.51; p=0.0008). Meta-regression models showed that male gender and a more severe inflammatory status [as expressed by disease activity score in 28 joints (DAS28), C-reactive protein (CRP) levels, and erythrocyte sedimentation rate (ESR)] significantly impacted on CCA-IMT. In conclusion, RA appears significantly associated with subclinical atherosclerosis and CV risk. These findings can be useful to plan adequate prevention strategies and therapeutic approaches.

Increased carotid intima-media thickness in rheumatoid arthritis: an update meta-analysis

This study aims to derive a more precise estimation on carotid intima-media thickness (CIMT) level in patients with rheumatoid arthritis (RA) and related factors. Studies published from January 1, 1982 to December 31, 2014 in English, which comparing CIMT between RA group and control group were searched in PubMed, Embase, and Cochrane Library databases. Heterogeneity test was performed, and publication bias was evaluated. Stata software 12.0 was used to perform the meta-analysis. Two-thousand one hundred sixty-three articles were obtained after searching databases, and 47 studies were finally included in the meta-analysis. The result of the analysis in random effect model showed that RA group had significantly higher CIMT than control group, with the standardized mean difference (SMD) of 1.04 and 95% CI (0.81,1.27). To evaluate the stability of our results, sensitivity analyses were performed, and the results showed no significant change when any one study was excluded. Subgroup analyses showed that region, race, age, BMI, and disease duration were associated with CIMT in RA patients. In summary, CIMT in RA patients is thicker than healthy controls, and it is influenced by region, race, age, BMI, and disease duration.

Haptoglobin increases with age in rat hippocampus and modulates Apolipoprotein E mediated cholesterol trafficking in neuroblastoma cell lines

Alteration in cholesterol metabolism has been implicated in the pathogenesis of several neurodegenerative disorders. Apolipoprotein E (ApoE) is the major component of brain lipoproteins supporting cholesterol transport. We previously reported that the acute-phase protein Haptoglobin (Hpt) binds ApoE, and influences its function in blood cholesterol homeostasis. Major aim of this study was to investigate whether Hpt influences the mechanisms by which cholesterol is shuttled from astrocytes to neurons. In detail it was studied Hpt effect on ApoE-dependent cholesterol efflux from astrocytes and ApoE-mediated cholesterol incorporation in neurons. We report here that Hpt impairs ApoE-mediated cholesterol uptake in human neuroblastoma cell line SH-SY5Y, and limits the toxicity of a massive concentration of cholesterol for these cells, while it does not affect cholesterol efflux from the human glioblastoma-astrocytoma cell line U-87 MG. As aging is the most important non-genetic risk factor for various neurodegenerative disorders, and our results suggest that Hpt modulates ApoE functions, we evaluated the Hpt and ApoE expression profiles in cerebral cortex and hippocampus of adolescent (2 months), adult (5 and 8 months), and middle-aged (16 months) rats. Hpt mRNA level was higher in hippocampus of 8 and 16 month-old than in 2-month old rats (p < 0.05), and Hpt concentration increased with the age from adolescence to middle-age (p < 0.001). ApoE concentration, in hippocampus, was higher (p < 0.001) in 5 month-old rats compared to 2 month but did not further change with aging. No age-related changes of Hpt (protein and mRNA) were found in the cortex. Our results suggest that aging is associated with changes, particularly in the hippocampus, in the Hpt/ApoE ratio. Age-related changes in the concentration of Hpt were also found in human cerebrospinal fluids. The age-related changes might affect neuronal function and survival in brain, and have important implications in brain pathophysiology.

Regulation of high-density lipoprotein metabolism

There is compelling evidence from human population studies that plasma levels of high-density lipoprotein (HDL) cholesterol correlate inversely with cardiovascular risk. Identification of this relationship has stimulated research designed to understand how HDL metabolism is regulated. The ultimate goal of these studies has been to develop HDL-raising therapies that have the potential to decrease the morbidity and mortality associated with atherosclerotic cardiovascular disease. However, the situation has turned out to be much more complex than originally envisaged. This is partly because the HDL fraction consists of multiple subpopulations of particles that vary in terms of shape, size, composition, and surface charge, as well as in their potential cardioprotective properties. This heterogeneity is a consequence of the continual remodeling and interconversion of HDL subpopulations by multiple plasma factors. Evidence that the remodeling of HDLs may impact on their cardioprotective properties is beginning to emerge. This serves to highlight the importance of understanding not only how the remodeling and interconversion of HDL subpopulations is regulated but also how these processes are affected by agents that increase HDL levels. This review provides an overview of what is currently understood about HDL metabolism and how the subpopulation distribution of these lipoproteins is regulated.

LCAT cholesterol esterification is associated with the increase of ApoE/ApoA-I ratio during atherosclerosis progression in rabbit

Apolipoprotein A-I and Apolipoprotein E promote different steps of reverse cholesterol transport, including lecithin-cholesterol acyltransferase stimulation. Our aim was to study the changes in the levels of Apolipoprotein A-I, Apolipoprotein E, and lecithin-cholesterol acyltransferase activity during atherosclerosis progression in rabbits. Quantitative echocardiographic parameters were analyzed in order to evaluate, for the first time, whether atherosclerosis progression in rabbit is associated to apolipoproteins changes and alteration of indices of cardiac function, such as systolic strain and strain rate of the left ventricle. Atherosclerosis was induced by feeding rabbits for 8 weeks with 2 % cholesterol diet. The HDL levels of cholesterol and cholesteryl esters were measured by HPLC. The lecithin-cholesterol acyltransferase activity was evaluated both ex vivo, as cholesteryl esters/cholesterol molar ratio, and in vitro. Apolipoproteins levels were analyzed by ELISA. The HDL levels of cholesterol and cholesteryl esters increased, during treatment, up to 3.7- and 2.5-fold, respectively, compared to control animals. The lecithin-cholesterol acyltransferase activity in vitro was halved after 4 weeks. During cholesterol treatment, Apolipoprotein A-I level significantly decreased, whereas Apolipoprotein E concentration markedly increased. The molar ratio Apolipoprotein E/Apolipoprotein A-I was negatively correlated with the enzyme activity, and positively correlated with both increases in the intima-media thickness of common carotid wall and cardiac dysfunction signs, such as systolic strain and strain rate of the left ventricle.

Carotid intima media thickness in rheumatoid arthritis as compared to control subjects: a meta-analysis

OBJECTIVES

Rheumatoid arthritis (RA) is associated with increased risk of cardiovascular disease. Carotid intima media thickness (cIMT) is frequently used to identify populations at elevated cardiovascular risk. A systematic literature search and meta-analysis were performed to evaluate cIMT difference between RA and controls.

METHODS

The literature was screened to identify all available studies comparing cIMT in RA patients and controls. Random effects meta-analysis was performed to estimate the overall mean cIMT difference between both groups. Meta-regression was performed to assess the influence of age and the degree of comparability regarding established cardiovascular risk factors on cIMT difference. Potential publication bias was examined by a funnel plot and Egger test.

RESULTS

From 22 studies, cIMT data were available from 1384 RA patients and 1147 controls. In 17 of the studies, RA patients had a statistically significantly greater cIMT. The overall mean cIMT difference was 0.09 mm (95%CI: 0.07-0.11 mm). Heterogeneity was observed (I(2) 72.5%, P < 0.001). A likely source of heterogeneity was the difference in cardiovascular risk factors between RA patients and controls at baseline, but not age. The funnel plot did not show a skewed or asymmetrical shape, which was supported by the Egger's test (P = 0.87).

CONCLUSIONS

Our observations support the current evidence base for an increased cardiovascular burden in RA and support the use of cIMT in observational studies in RA patients. The next step is to determine its utility as a surrogate cardiovascular risk marker in RA in prospective studies.

Comparison of serum apolipoprotein A-I between Chinese multiple sclerosis and other related autoimmune disease

Background

Serum apolipoprotein (apo) A-I was considered to be an immune regulator and could suppress pro-inflammatory cytokines generated by activated T cell in some autoimmune diseases. However, the change of serum apoA-I levels in multiple sclerosis (MS) patients is unknown.

Methods

In the presentation we performed a study on serum apoA-I levels in the patients with MS. We enrolled some age and gender matched patients with MS, autoimmune demyelinating diseases (Guillain-Barre Syndrome and Clinically Isolated Syndrome), neuroinflammatory diseases (viral encephalitis), autoimmune connective diseases (rheumatoid arthritis and systemic lupus erythematosus) and healthy control groups, and tested their serum lipids levels: total cholesterol (TC), triglyceride (TG), high-density lipoproteins (HDL), apolipoproteinB100 (apoB100), apolipoproteinA-I (apoA-I).

Results

For all patients, age had no effect on serum apoA-I levels (P > 0.05). Meanwhile, we proved the highest serum apoA-I levels in MS patients and the lowest serum apoA-I levels in SLE patients. Serum apoA-I levels was significantly elevated in female MS patients (P = 0.033; P < 0.05).

Conclusion

In short we believed that patients with MS and other autoimmune demyelination had significantly decreased serum levels of apo A-I.

Insulin resistance is an independent risk factor for atherosclerosis in rheumatoid arthritis

The objective of this study was to investigate the relationship between insulin resistance (IR) and subclinical atherosclerosis in patients with rheumatoid arthritis (RA). Carotid artery intima media thickness (IMT), using ultrasound evaluation, and other clinical and laboratory variables were investigated in 45 RA outpatients and in 48 controls with soft tissue disorders. IR was assayed by homeostasis model assessment (HOMA2) and metabolic syndrome by National Cholesterol Education Program Adult Treatment Panel (NCEP ATP III) criteria. Insulin resistance, as defined by HOMA2-IR>1, was seen in 40 (88.9%) RA patients and in three (6.2%) controls (p<0.001). No significant difference was detected in the prevalence of metabolic syndrome. The median IMT was greater in RA patients (0.76 mm; interquartile range [IQR] 0.65, 0.85) than in the controls (0.66 mm; IQR 0.60, 0.72) (p<0.001). Dividing the RA patients according to the cut-off IMT value (0.72 mm), a difference was detected in both systolic (p=0.04) and diastolic blood pressure (p=0.02), disease activity score (DAS28) (p=0.008), HOMA2-IR (p<0.001) and cumulative oral steroid dose (p=0.001). Moreover, the frequency of cases with increased IMT was higher in glucocorticoid users than in non-users (21/23 vs. 9/22, respectively) (p<0.001). Spearman's rho correlation showed a significant positive relationship between IMT and HOMA2-IR (p<0.001). Multivariate stepwise analysis selected HOMA2-IR plus diastolic BP plus glucocorticoid exposure as the best predictive model for subclinical atherosclerosis (R2c=0.577, F=21, p<0.001). In conclusion, this study showed a significantly higher prevalence of IR in RA patients and pointed out a significant association between IR and subclinical atherosclerosis. This relationship may be driven primarily by exposure to steroid therapy.