Lipoprotein profile in limited systemic sclerosis

Metabolomic signature identifies HDL and apolipoproteins as potential biomarker for systemic sclerosis with interstitial lung disease

BACKGROUND

High-density lipoproteins (HDL) affect endothelial functions such as the expression of endothelial cell adhesion molecules and exert anti-apoptotic/-thrombotic functionalities. Therefore, profound analysis of lipoproteins may unveil biomarkers for (micro-)vasculopathy in systemic sclerosis (SSc) and mortality determining disease manifestations like interstitial lung disease (SSc-ILD). Because nuclear magnetic resonance (NMR) spectroscopy provides a wide range of lipoprotein parameters beyond the capabilities of classical analyses it has been used herein to examine lipoprotein profiles in SSc.

METHODS

To detect the metabolic and lipidomic profile serum samples from clinically well-characterized SSc patients (n = 100) and age-and sex-matched healthy controls (n = 40) were analyzed by 1H NMR spectroscopy using Bruker's in-vitro diagnostic research (IVDr) protocol. Statistical analyses were performed to validate significant findings and to search for associations between lipoproteins and clinical phenotypes.

RESULTS

Patients with SSc-ILD and lung fibrosis displayed reduced HDL levels. Furthermore, a reduction in apolipoprotein A1 + A2 and its HDL fractions reflected a distinct lipoprotein profile for SSc-ILD patients. This association was independent of potential clinical confounders for dyslipidemia. Notably, in SSc-ILD HDL levels correlate with FVC (forced vital capacity), DLCO (diffusion capacity of the lungs for carbon monoxide), and the modified Rodnan-Skin-Score.

CONCLUSION

These results suggest HDL and its lipoproteins may be considered as potential new biomarkers for SSc-ILD. Immune-mediated HDL effects on the endothelium facilitate microvasculopathy - one of the pathophysiological hallmarks in SSc. Therefore, a closer prospective evaluation of the capability of HDL-determination and its lipoproteins regarding a more individualized evaluation of SSc-ILD is warranted.

High-Protein Nutritional Supplements Improve Nutritional Status in Malnourished Patients with Systemic Sclerosis

(1) Background: Impaired nutritional status in systemic sclerosis (SSc) is prevalent. (2) Objective: This study aimed to identify pre-cachexia and malnutrition in SSc patients and to estimate the effectiveness of a high-protein oral nutritional supplement (ONS) in improving their nutritional status. (3) Materials and methods: The SSc population comprised 56 patients and a control group of 49 healthy persons. After a baseline clinical evaluation, bioelectrical impedance analysis (BIA), and laboratory tests, SSc patients were divided into well-nourished, pre-cachectic, and malnourished categories. SSc patients with a nutritional disbalance received a high-protein ONS once daily for 3 months. Patients were reassessed at 3 and 12 months after inclusion in the study. (4) Results: SSc patients, in comparison to the control group, had a significantly lower seven-point SGA value [6(0) vs. 7(1), p < 0.001)], lean tissue mass [LTM, 35.1 (10.5) vs. 40.1 (10.10), p = 0.008], and lean tissue index [LTI, 13.5 (3) vs. 14.9 (4), p = 0.009]. Of the 56 SSc patients, 40 (71.4%) were well nourished, 5 (8.9%) had pre-cachexia, and 11 (19.7%) were malnourished. A high-protein ONS in the pre-cachexia group stabilized the SGA value, anthropometric measurements, and BIA after 3 and 12 months. In malnourished patients, it significantly improved the SGA value [5(0) vs. 6(0), p = 0.002], LTI [12.1 (2.1) vs. 12.7 (3.2), p = 0.021] and LTM [31.1 (7.7) vs. 35.1 (9.1), p = 0.021], and that effect remained stable at 12 months. (5) Conclusion: Malnutrition is a common complication of SSc that can be improved with nutritional intervention.

Influence of visceral adiposity on cardiovascular risk in patients with systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease characterized by systemic inflammation, endothelial dysfunction, generalized fibrosis and high cardiovascular mortality. The evaluation of cardiovascular risk through the visceral adiposity index (VAI) has been helpful due to its direct relationship to the body and visceral fat percentage. We evaluated the influence of body composition and anthropometrics on cardiovascular risk as measured by VAI in healthy controls (HC) and SSc. An analytical cross-sectional study of 66 participants (33 SSc and 33 HC), mean age 52.7 ± 10, 95% women, was conducted from August 2020 to January 2021. Inclusion criteria in cases were consecutive patients with SSc (ACR/EULAR 2013), 63.6% were diffuse cutaneous (dcSS) subtype, and 36.4 were limited cutaneous (lcSS) subtype. HC was matched by age and gender. Serum lipid profiles and InBody anthropometrics were analyzed and compared. We performed descriptive statistics, bivariate analysis with Student's t, or Mann-Whitney U, correlation and chi-square according to the variable type and distribution. Total cholesterol was significantly higher in SSc than HC (345 vs 194, p = < 0.001). The BMI was higher in HC (26.2 vs 28.9, p < 0.001). Kilograms of muscle (19.8 vs 28.9, p < 0.001) and total fat (23.4 vs 28.9, p < 0.001) were lower in SSc patients compared to HC. VAI was similar when BMI < 25, but significantly higher when BMI > 25 in SSc than in HC (3 vs 1.9, p = 0.030). The increase in BMI at overweight or obese in SSc is associated with a significant increase in cardiovascular risk.

Association Between Lipid Profile and Risk of Incident Systemic Sclerosis: A Nationwide Population-Based Study

Background and Aims

Lipid metabolism is altered in systemic sclerosis (SSc), mediating activation of immune cells and fibroblasts. However, it is unclear whether altered lipid profile is associated with a risk of developing SSc. We aimed to assess the association between lipid profile and risk of incident SSc.

Methods

From a Korean nationwide database, individuals without SSc who underwent national health check-ups in 2009 were selected and followed-up through 2019. Serum levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride were measured on the health check-up date in 2009. Individuals who developed SSc during follow-up were identified. Multivariable Cox models were performed to estimate the risk of incident SSc according to TC, HDL-C, LDL-C, and triglyceride levels, respectively.

Results

Of the 9,894,996 individuals selected, 1355 individuals developed SSc during a mean follow-up of 9.2 years (incidence rate=1.49 per 100,000 person-years). Levels of TC (adjusted hazard ratio [aHR] 0.959, 95% confidence interval [CI] 0.945-0.974), HDL-C (aHR 0.968, 95% CI 0.950-0.987), LDL-C (aHR 0.968, 95% CI 0.952-0.983) were inversely associated with the risk of incident SSc, whereas no significant association was observed between levels of triglyceride (aHR 1.004, 95% CI 0.998-1.011) and risk of incident SSc.

Conclusion

Serum levels of TC, HDL-C, and LDL-C were inversely associated with the risk of incident SSc. Our findings provide new insights that altered lipid profile could be considered a non-causal biomarker associated with incident SSc, which could help early diagnosis. The underlying mechanism for this association needs further studies.

Malondialdehyde Serum Levels in Patients with Systemic Sclerosis Relate to Dyslipidemia and Low Ventricular Ejection Fraction

Systemic sclerosis (SSc) is a chronic disease characterized by vasculopathy with the involvement of dysfunctional microcirculatory vessels. Features of the disease include progressive fibrosis of the skin and internal organs and systemic inflammation characterized by the presence of circulating autoantibodies and proinflammatory cytokines. Furthermore, macrovascular disease and atherosclerosis are more common in patients with SSc than in the general population. Oxidative stress plays a crucial role in the development of several processes, including endothelial dysfunction, cancer, inflammation, and atherogenesis. Malondialdehyde (MDA) is a well-established marker of oxidative stress. In this work, we have analyzed the relationship between serum MDA levels and clinical, laboratory, and vascular characteristics in a well-characterized cohort of 53 patients with SSc. A multivariable analysis was performed to study the relationship between circulating MDA and disease characteristics in patients with SSc. Cardiovascular assessment was also performed, including ultrasonography of the carotid and aorta, and echocardiography. MDA showed a significant and positive relationship with the serum levels of lipid profile molecules such as total cholesterol (β coefficient = 0.006 (95% CI: 0.0004 to 0.01), nmol/mL, p = 0.037) and LDL cholesterol (β coefficient = 0.008 (95% CI: 0.001 to 0.01) nmol/mL, p = 0.017). On the contrary, most manifestations of the disease, including skin, lung, and joint involvement, as well as the presence of digital ulcers, were not related to MDA. However, high MDA levels were significantly and independently associated with lower ventricular ejection fraction after adjustment for covariates (β coefficient = -0.04 (95% CI: -0.06 to -0.02), nmol/mL, p = 0.001). In conclusion, serum MDA levels were related to higher levels of total and LDL cholesterol and a lower left ventricular ejection fraction in patients with SSc. MDA could serve as a potential biomarker of dyslipidemia and heart failure in SSc.

Understanding and managing cardiac involvement in systemic sclerosis

INTRODUCTION

Cardiac involvement is common in systemic sclerosis occurring in up to 80% of patients. Primary myocardial dysfunction results from impairment of coronary microvascular circulation, myocardial inflammation and fibrosis with the prevalence of atherosclerosis remaining contradictory.

AREAS COVERED

This review presents the various aspects of cardiac involvement in SSc from a pathophysiological, clinical, diagnostic and therapeutic standpoint. Imaging modalities with emerging role in the understanding of mechanisms and prompt diagnosis of myocardial fibrosis namely cardiac magnetic resonance are also discussed.

EXPERT OPINION

Cardiac involvement in SSc - and particularly primary myocardial disease - remains a challenge as clinical symptoms manifest in advanced stages of heart failure and convey poor prognosis. Over the last years the introduction of sophisticated imaging methods of myocardial function has resulted in a better understanding of the underlying pathophysiological processes of myocardial damage such as microvasculopathy, inflammation, diffuse or focal fibrosis. Such developments could contribute to the identification of patients at higher risk for subclinical heart involvement for whom diligent surveillance and prompt initiation of therapy with cardioprotective and/or immunosuppressive drugs coupled with invasive interventions namely radiofrequency ablation, implantable cardioverter-defibrillator when indicated, may improve long-term outcomes.

Atherosclerosis in Vietnamese patients with systemic sclerosis and its relation to disease and traditional risk factors

Objective

The aim of this study was to determine the frequency of clinical and subclinical atherosclerosis in Vietnamese patients with SSc and the risk factors for subclinical atherosclerosis.

Methods

A case–control study of 46 patients with SSc who met the ACR criteria for the disease and 42 healthy age- and sex-matched controls of Kinh ethnicity was conducted. Clinical data including cardiovascular disease (CVD) events were collected. Serum levels of blood lipids and high-sensitivity CRP were determined. Carotid artery intima–media thickness (IMT) and carotid plaques were measured by carotid Doppler ultrasonography.

Results

Patients with SSc, of whom 96% had dcSSc, reported a higher number of CVD events compared with the controls (21.7 vs 0%; P = 0.0065). They exhibited low serum levels of high-density lipoprotein cholesterol and high levels of total cholesterol compared with controls (P = 0.01 and P = 0.03, respectively). Common carotid artery IMT was significantly higher in SSc patients compared with controls [mean (s.d.): 0.61 (0.12) vs 0.47 (0.07) mm; P < 0.0001]. Carotid artery IMT in SSc showed significant positive correlations with age, disease duration, total cholesterol and low-density lipoprotein cholesterol (P < 0.05). Thirteen patients with SSc (28.3%) but no controls had carotid atherosclerotic plaques. Patients with plaque had a higher mean modified Rodnan skin score and higher mean IMT compared with patients without plaque.

Conclusion

We confirmed an increased risk of CVD events and signs of subclinical atherosclerosis in patients with SSc of Kinh ethnicity and both traditional and disease-related risk factors for CVD.

Lipid Alterations in Systemic Sclerosis

Background: Systemic sclerosis (SSc) is an autoimmune disease with an elusive etiology and poor prognosis. Due to its diverse clinical presentation, a personalized approach is obligatory and needs to be based on a comprehensive biomarker panel. Therefore, particular metabolomic studies are necessary. Lipidomics addressed these issues and found disturbances in several crucial metabolic pathways.

Aim of Review: The review aims to briefly summarize current knowledge related to lipid alterations in systemic sclerosis, highlight its importance, and encourage further research in this field.

Key Scientific Concepts of Review: In this review, we summarized the studies on the lipidomic pattern, fatty acids, lipoproteins, cholesterol, eicosanoids, prostaglandins, leukotrienes, lysophospholipids, and sphingolipids in systemic sclerosis. Researchers demonstrated several alternate aspects of lipid metabolism. As we aimed to present our findings in a comprehensive view, we decided to divide our findings into three major groups: “serum lipoproteins,” “fatty acids and derivatives,” and “cellular membrane components,” as we do believe they play a prominent role in SSc pathology.

Changes in Plasma Phospholipid Metabolism Are Associated with Clinical Manifestations of Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune disease with fibrosis of the skin and/or internal organs, causing a decrease in quality of life and survival. There is no causative therapy, and the pathophysiology of the SSc remains unclear. Studies showed that lipid metabolism was relevant for autoimmune diseases, but little is known about the role of lipids in SSc. In the present study, we sought to explore the phospholipid profile of SSc by using the lipidomics approach. We also aimed to analyze lipidomics results for different clinical manifestations of SSc. Experiments were performed using high-performance liquid chromatography coupled to mass spectrometry for the lipidomic profiling of plasma samples from patients with SSc. Our study showed, for the first time, significant changes in the level of phospholipids such as plasmalogens and sphingomyelins from the plasma of SSc patients as compared to controls. Phosphatidylcholine plasmalogens species and sphingomyelins were significantly increased in SSc patients as compared to controls. Our results also demonstrated a significant association of changes in the metabolism of phospholipids (phosphatidylcholine and phosphatidylethanolamine plasmalogens species and sphingomyelins) with different clinical manifestations of SSc. Further lipidomic studies might lead to the detection of lipids as new biomarkers or therapeutic targets of SSc.

HDL cholesterol efflux capacity and lipid profile in patients with systemic sclerosis

OBJECTIVE

It is well established that patients with systemic sclerosis (SSc) have a disrupted lipid profile and an increased cardiovascular risk. Cholesterol efflux capacity (CEC), the ability of high-density lipoprotein (HDL)-cholesterol to accept cholesterol from macrophages, has been linked to cardiovascular events. The aim of this study was to establish whether CEC and lipid profile were impaired in SSc patients with respect to controls and whether these changes were associated with disease-related data.

METHODS

Cross-sectional study encompassed 188 individuals: 73 SSc patients and 115 controls. CEC, using an in vitro assay, and lipoprotein serum concentrations were assessed in patients and controls. A multivariable analysis was performed to study the differences in CEC between patients and controls, and if SSc-related data could explain such differences.

RESULTS

The multivariable analysis adjusted for demographic characteristics, cardiovascular risk factors, and lipid-related molecules showed that total cholesterol (beta coefficient: - 22 [95%CI - 37 to - 7], p = 0.004), triglycerides (beta coefficient: 24 [95%CI 2-47], p = 0.033), lipoprotein A (beta coefficient: 22 [95%CI 2-43], p = 0.033), and CEC (beta coefficient: - 6 [95%CI - 10 to - 2]%,p = 0.002) were significantly different between patients and controls. Skin thickness, as assessed by modified Rodnan skin score, was independently associated with a lower CEC (beta coefficient: - 0.21 [95%CI - 0.37 to - 0.05]%, p = 0.011) after multivariable adjustment.

CONCLUSION

SSc patients show an abnormal lipid profile with respect to controls including CEC. Skin thickness is independent and inversely associated with CEC in SSc patients.

Comorbidity burden in systemic sclerosis: beyond disease-specific complications

Systemic sclerosis (SSc) is a chronic, systemic disease characterized by fibrosis of the skin and internal organs, vasculopathy, and auto-immune activation. On the top of severe organ involvement such as interstitial lung and myocardial fibrosis, pulmonary hypertension, and renal crisis, individuals diagnosed with SSc may suffer from a number of comorbidities. This is a narrative review according to published recommendations and we searched the online databases MEDLINE and EMBASE using as key words the following terms: systemic sclerosis, scleroderma, myocardial fibrosis in combination with micro- and macro-vascular disease, cardiac involvement, atherosclerosis, cardiovascular disease and coronary arteries, infections, cancer, depression, osteoporosis, and dyslipidemia. Although data are usually inconclusive it appears that comorbidities with significant impact on life expectancy, namely cardiovascular disease, infections, and cancer as well as phycological disorders affecting emotional and mental health are highly prevalent in SSc population. Thereafter, the aim of this review is to summarize the occurrence and the clinical significance of such comorbidities in SSc population and to discuss how rheumatologists can incorporate the management of these conditions in daily clinical practice.

A critical view on cardiovascular risk in systemic sclerosis

Systemic Sclerosis (SSc) is an autoimmune disorder characterized by microvascular injury and diffuse fibrosis of the skin and internal organs. While macrovascular disease and higher risk for cardiovascular events are well documented in other systemic rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus, the presence and extent of atherosclerosis among patients with SSc is yet to be established. Primary cardiac involvement, due to impairment of coronary microvascular circulation and myocardial fibrosis, considerably affects prognosis and life expectancy of individuals with SSc, representing one of the leading causes of death in this population. On the other hand the existence and prevalence of atherosclerotic coronary disease remains an issue of debate as studies comparing structural and morphological markers of atherosclerosis and cardiovascular events between SSc patients and the general population have yielded controversial results. The aim of this review is to summarize recent literature about the prevalence of cardiovascular disease in SSc, review the surrogate markers of CVD that have been evaluated and examine whether common pathogenic mechanisms exist between SSc and macrovascular disease.

Cardiovascular disease in systemic sclerosis

Cardiovascular (CV) system involvement is a frequent complication of autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). It still remains unclear if a premature atherosclerosis (ATS) occurs even in systemic sclerosis (SSc). Although microvascular disease is a hallmark of SSc, in the last few years a number of studies highlighted a higher prevalence of macrovascular disease in SSc patients in comparison to healthy individuals and these data have been correlated with a poorer prognosis. The mechanisms promoting ATS in SSc are not fully understood, but it is believed to be secondary to multi-system organ inflammation, endothelial wall damage and vasculopathy. Both traditional risk factors and endothelial dysfunction have been proposed to participate to the onset and progression of ATS in such patients. In particular, endothelial cell injury induced by anti-endothelial antibodies, ischemia/reperfusion damage, immune-mediated cytotoxicity represent the main causes of vascular injury together with an impaired vascular repair mechanism that determine a defective vasculogenesis. Aim of this review is to analyse both causes and clinical manifestations of macrovascular involvement and ATS in SSc.

Cardiovascular involvement in autoimmune diseases

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD.

Serum prolidase enzyme activity and oxidative status in patients with fibromyalgia

OBJECTIVE

This study was performed to investigate serum prolidase enzyme activity and oxidative stress in patients diagnosed with fibromyalgia (FM).

METHODS

The study population consisted of 40 patients with a previous diagnosis of FM and 30 healthy subjects. We measured serum prolidase enzyme activity, total antioxidant status (TAS), total oxidative status (TOS), oxidative stress index (OSI), and paraoxonase-1 (PON-1) levels.

RESULTS

On average, FM patients were diagnosed within 3.2 years of symptom onset, and patients had a mean of 14 tender points. There were no significant differences between patients and controls in age, body mass index, serum TAS, or PON-1 levels. However, patients with FM demonstrated higher serum prolidase activity, TOS, and OSI than the control group. Serum prolidase activity was positively correlated with serum TOS, OSI, and visual analog scale pain and fatigue scores. No correlation was found between serum prolidase activity and FM duration or the average number of tender points.

DISCUSSION

Our results demonstrate a previously unreported association between serum prolidase enzyme activity and FM. Increased prolidase activity may contribute to the pathogenesis of FM, and measuring serum prolidase enzyme activity may be a useful FM biomarker.

Ischemic heart disease in systemic inflammatory diseases. An appraisal

Systemic inflammatory diseases are inflammatory syndromes that are associated with increased cardiovascular morbidity and mortality. The link between inflammatory and cardiovascular diseases can be attributed to coexistence of classical risk factors and of inflammatory mechanisms activated in systemic inflammatory diseases and involving the immune system. Yet, clinical implications of these findings are not entirely clear and deeper knowledge and awareness of cardiac involvement in inflammatory diseases are necessary. The aims of this review are to summarize cardiac involvement in systemic inflammatory diseases and to identify areas where evidence is currently lacking that deserve further investigation in the future.

Atherosclerosis in systemic sclerosis: a systematic review and meta-analysis

OBJECTIVE

Systemic sclerosis (SSc) is characterized by calcification, vasculopathy, and endothelial wall damage, all of which can increase the risk of developing atherosclerosis and cardiovascular disease. The aim of this study was to perform a systematic review and meta-analysis to determine whether the risk of atherosclerosis is increased in SSc patients compared to healthy individuals.

METHODS

A systematic search was performed to identify studies published in PubMed and the Cochrane database up to May 2010, and recently published abstracts were also reviewed. Two reviewers independently screened articles to identify studies comparing the rate of atherosclerosis in SSc patients to that in healthy controls. The studies utilized one of the following methods: angiography, Doppler ultrasound to assess plaque and carotid intima-media thickness (IMT), computed tomography, magnetic resonance imaging, flow-mediated vasodilation (assessed as the FMD%), the ankle-brachial index, or autopsy. For carotid IMT and FMD% values, we computed a pooled estimate of the summary mean difference and explored predictors of carotid IMT using random-effects meta-regression.

RESULTS

Of the 3,156 articles initially identified, 31 were selected for systematic review. The meta-analysis included 14 studies assessing carotid IMT and 7 assessing brachial artery FMD%. Compared to healthy controls, SSc patients had a higher prevalence of coronary atherosclerosis, peripheral vascular disease, and cerebrovascular calcification. Meta-analysis showed that SSc patients had increased carotid IMT (summary mean difference 0.11 mm, 95% confidence interval [95% CI] 0.05 mm, 0.17 mm; P = 0.0006) and lower FMD% (summary mean difference -3.07%, 95% CI -5.44%, -0.69%; P = 0.01) compared to controls. There was marked heterogeneity between the studies, which was mainly attributable to variations in disease duration and differences in the mean/median age between SSc patients and controls.

CONCLUSION

Patients with SSc have an increased risk of atherosclerosis compared to healthy subjects. Further studies should elucidate the mechanism of this increased risk.

Cardiovascular disease in systemic sclerosis--an emerging association?

Microvascular disease is a prominent feature of systemic sclerosis (SSc) and leads to Raynaud's phenomenon, pulmonary arterial hypertension, and scleroderma renal crisis. The presence of macrovascular disease is less well established, and, in particular, it is not known whether the prevalence of coronary heart disease in SSc is increased. Furthermore, in terms of cardiac involvement in SSc, there remains conjecture about the relative contributions of atherosclerotic macrovascular disease and myocardial microvascular disease. In this review, we summarize the literature describing cardiovascular disease in SSc, discuss the pathophysiological mechanisms common to SSc and atherosclerosis, and review the surrogate markers of cardiovascular disease which have been examined in SSc. Proposed mediators of the vasculopathy of SSc which have also been implicated in atherosclerosis include endothelial dysfunction, a reduced number of circulating endothelial progenitor cells, and an increased number of microparticles. Excess cardiovascular risk in SSc is suggested by increased arterial stiffness and carotid intima thickening and reduced flow-mediated dilatation. Cohort studies of adequate size are required to resolve whether this translates into an increased incidence of cardiovascular events in patients with SSc.

Atherosclerosis and macrovascular involvement in systemic sclerosis: myth or reality

Systemic sclerosis (SSc) is a chronic disease of unknown etiology, characterized by enhanced fibrosis, and microvascular abnormalities. During the past several decades, the death rates due to cardiovascular disease or cerebrovascular disease in SSc patients substantially increased and are currently responsible for 20-30% of mortality. Various autoimmune rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus accelerate atherosclerosis. Although microvascular disease is a hallmark of SSc, an ongoing debate exists regarding the presence and extent of macrovascular diseases and the presence of accelerated atherosclerosis in SSc patients. Despite conflicting results as to intima-media thickness (IMT) in SSc patients, the most recent and largest study has found no difference in either plaque occurrence or IMT. Additionally, abnormal coronary flow reserve in SSc patients appears to be due to microvascular involvement rather than atherosclerosis of the epicardial coronary arteries. Angiographic findings as well as computed tomography studies have generated conflicting reports as to coronary atherosclerosis in SSc. Herein, we review the current knowledge of macrovascular involvement and atherosclerosis in SSc. The differences between SSc and other autoimmune rheumatic diseases in the presence and extent of atherosclerosis need to be further investigated.

Plasma levels of high-density lipoprotein cholesterol and outcomes in pulmonary arterial hypertension

RATIONALE

High-density lipoprotein cholesterol (HDL-C) promotes healthy vascular function, and it is decreased in insulin resistance. Insulin resistance predisposes to pulmonary vascular disease.

OBJECTIVES

We hypothesized that HDL-C is associated with clinical outcomes in pulmonary arterial hypertension (PAH).

METHODS

Plasma HDL-C concentrations were measured in 69 patients with PAH (age, 46.7 +/- 12.9 yr; female, 90%) and 229 control subjects (age, 57 +/- 13 yr; female, 48%). Clinical outcomes of interest included hospitalization for PAH, lung transplantation, and all-cause mortality. Survival and time to clinical worsening curves were derived by the Kaplan-Meier method. Cox regression modeling of outcome versus HDL-C with individual covariate adjustments was performed.

MEASUREMENT AND MAIN RESULTS

HDL-C was low in subjects with PAH compared with control subjects (median, interquartile range: PAH: 36, 29-40 mg/dl; control subjects: 49, 40-60 mg/dl; P < 0.001). An HDL-C level of 35 mg/dl discriminated survivors from nonsurvivors, with a sensitivity of 100% and specificity of 60%. After a median follow-up of 592 days, high HDL-C was associated with decreased mortality (hazard ratio for every 5-mg/dl increase in HDL-C, 0.643; 95% confidence interval, 0.504-0.822; P = 0.001) and less clinical worsening (hazard ratio for every 5-mg/dl increase in HDL-C, 0.798; 95% confidence interval, 0.663-0.960; P = 0.02). HDL-C remained a significant predictor of survival after adjusting for cardiovascular risk factors, C-reactive protein, indices of insulin resistance, and severity of PAH (all P < 0.05).

CONCLUSIONS

Low plasma HDL-C is associated with higher mortality and clinical worsening in PAH. This association does not appear to be explained by underlying cardiovascular risk factors, insulin resistance, or the severity of PAH.

Subclinical atherosclerosis in scleroderma patients

OBJECTIVE

To investigate subclinical atherosclerosis in patients with systemic sclerosis (SSc).

METHODS

Sixty-six patients with SSc who met the American College of Rheumatology criteria for the disease were included. The serum levels of total cholesterol (TC), triglycerides, high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL-C) were determined in all patients. Carotid artery intima-media thickness (IMT) and carotid plaques were measured. Patients with a history of atherosclerosis, hypertension, smokers, or patients suffering from conditions that affect the lipid profile, such as diabetes mellitus, hypothyroidism, liver or kidney diseases, Cushing's syndrome, obesity, and a history of familial dyslipidaemia, were excluded. Patients receiving medication affecting lipid metabolism were also excluded from the study. Fifty-one age- and sex-matched non-smoking volunteers were used as controls.

RESULTS

Sixty patients were investigated. Six were excluded. Of these, two were smokers, two had diabetes mellitus, one hypothyroidism, and one had hypertension treated with diuretics. Patients with SSc exhibited mild dyslipidaemia expressed mainly by low serum levels of HDL-C and high TC (p < 0.001 and p < 0.021, respectively) compared to controls. In addition, the atherogenic ratio LDL-C/HDL-C was significantly higher among SSc patients (p < 0.0001). Common carotid artery IMTs were higher in SSc compared to controls (0.77 +/- 0.2 vs. 0.59 +/- 0.14, p < 0.0001). No correlation between IMTs and any SSc features were found. Logistic regression analysis showed an independent association of scleroderma with IMTs and TC.

CONCLUSION

The scleroderma patients exhibited an atherogenic lipid profile and subclinical atherosclerosis and have an increased risk for cardiovascular events.

Accelerated atherosclerosis in systemic lupus erythematosus and other connective tissue diseases

Connective tissue diseases are associated with increased morbidity and mortality related to a higher rate of cardiovascular events and higher prevalence of subclinical atherosclerosis. Atherosclerosis is now considered a multifactorial process where autoimmunity and chronic inflammation play an important pathogenic role. In systemic autoimmune rheumatic diseases in general, and in systemic lupus erythematosus in particular, atherosclerosis cannot be explained by traditional cardiovascular risk factors alone. Cellular and humoral mechanisms, together with specific factors associated with the disease itself and/or its treatments, have been advocated to explain the acceleration of arterial wall organic damage in these patients. Endothelial dysfunction, carotid intima-media thickness and plaque evaluations provide accurate detection of atherosclerotic process at a preclinical stage, before appearance of clinical disease, allowing preventive measure introduction with the aim to modify the cardiovascular risk in subjects with systemic autoimmune rheumatic diseases.

Lack of antilipoprotein lipase antibodies in Takayasu's arteritis

Background. Antilipoprotein lipase (anti-LPL) antibodies were described in rheumatic diseases. In systemic lupus erythematosus they were highly associated with inflammatory markers and dyslipidemia, and may ultimately contribute to vascular damage. The relevance of this association in Takayasu's arteritis, which is characterized by major inflammatory process affecting vessels, has not been determined. Objectives. To analyze the presence of anti-LPL antibodies in patients with Takayasu's arteritis and its association with inflammatory markers and lipoprotein risk levels. Methods. Thirty sera from patients with Takayasu's arteritis, according to ACR criteria, were consecutively included. IgG anti-LPL was detected by a standard ELISA. Lipoprotein risk levels were evaluated according to NCEP/ATPIII. Inflammatory markers included ESR and CRP values. Results. Takayasu's arteritis patients had a mean age of 34 years old and all were females. Half of the patients presented high ESR and 60% elevated CRP. Lipoprotein NCEP risk levels were observed in approximately half of the patients: 53% for total cholesterol, 43% for triglycerides, 16% for HDL-c and 47% for LDL-c. In spite of the high frequency of dyslipidemia and inflammatory markers in these patients no anti-LPL were detected. Conclusions. The lack of anti-LPL antibodies in Takayasu's disease implies distinct mechanisms underlying dyslipidemia compared to systemic lupus erythematosus.

Flow-mediated vasodilation and carotid intima-media thickness in systemic sclerosis

Increased evidence suggests an accelerated macrovascular disease in systemic sclerosis (SSc). Brachial artery flow-mediated vasodilation (FMD) and carotid intima-media thickness (IMT) are two indicators of subclinic cardiovascular disease and are frequently used as surrogate measures of subclinic atherosclerosis. The aim of this study was to evaluate macrovascular involvement in SSc. We studied 35 SSc patients (6 males and 29 females; 11 with diffuse and 24 with limited disease) and 20 healthy controls. Brachial artery FMD was assessed by method described by Celermajer in all patients and 13 control subjects. IMT was measured using high-resolution B-mode ultrasonography in patients and controls. Traditional risk factors for atherosclerosis (hypertension, dyslipidemia, and smoke) were also assessed. FMD was significantly impaired (3.41% +/- 4.56% versus 7.66% +/- 4.24%; P < 0.037) and IMT was significantly elevated compared with healthy controls (0.93 +/- 0.29 mm versus 0.77 +/- 0.13 mm; P < 0.005). FMD was not significantly different in SSc with increased IMT compared with those with normal IMT). No correlation was found between risk factors for atherosclerosis and the impairment of FMD or IMT in SSc patients. The impairment of endothelial function and structural changes of large vessels are evident in SSc, but do not seem associated with traditional risk factors for atherosclerosis. Prospective studies including also clinical outcomes are needed to assess the features and significance of macrovacular involvement in SSc.

Lipoprotein[a] and the lipid profile in patients with systemic sclerosis

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune disorder of the connective tissue characterized by widespread vascular lesions and fibrosis, associated with endothelial dysfunction, that might finally promote occlusive vascular complications. Little is known so far on the lipid profile of these patients.

METHODS

To investigate the potential contribution of lipid abnormalities in genesis and progression of vascular occlusive complications, an extensive lipid profile, including total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, total cholesterol to HDL-C ratio, the atherogenic index of plasma, lipoprotein[a] (Lp[a]) and high-sensitive C Reactive Protein (Hs-CRP), was assessed in 31 consecutive female SSc patients and 33 matched healthy controls.

RESULTS

When compared to healthy matched controls, SSc patients displayed statistically significant differences in median and 25-75th percentile distribution of Lp[a] (110 mg/l, 51-389 mg/l vs. 79 mg/l, 29-149 mg/l; P =0.005) and in the mean concentration of Hs-CRP (4.49 +/- 5.06 mg/l vs. 1.36 +/- 1.19 mg/l; P =0.001), but not in the other lipid parameters. When compared to the current NCEP or AHA/ACC goals, the values distributions and the relative percentage of patients with undesirable or abnormal vales were statistically different for Lp[a] (29% versus 3%) and Hs-CRP (42% vs. 12%) (both P <0.001).

CONCLUSIONS

If further studies will strengthen these preliminary findings, owing to the growing evidence that Lp[a] might act in synergy with other defined prothrombotic conditions in the pathogenesis of a variety of vascular disorders, we hypothesize that Lp[a] measurement might be useful in SSc to identify and eventually treat subsets of patients more predisposed to develop thrombotic complications.