Ceramides: a potential cardiovascular biomarker in young adult childhood cancer survivors?

Aims

The aim of this study was to investigate circulating ceramides involved in cardiovascular disease (CVD) in young adult childhood cancer survivors (CCS) and their correlations to previously reported adverse cardiovascular changes in this cohort.

Methods and results

Fifty-seven CCS and 53 healthy controls (age 20-30 years) were studied. Plasma long-chain ceramides, known to be cardiotoxic (C16:0, C18:0, C24:0, and C24:1), were analysed by mass spectrometry. The coronary event risk test 2 (CERT2) score was calculated from the ceramide data. Cardiac and carotid artery ultrasound data and lipid data available from previous studies of this cohort were used to study partial correlations with ceramide and CERT2 score data. All four analysed ceramides were elevated in CCS compared with controls (P ≤ 0.012). The greatest difference was noted for C18:0, which was 33% higher in CCS compared with controls adjusted for sex, age, and body mass index (BMI) (P < 0.001). The CERT2 score was higher in CCS compared with controls (P < 0.001). In the CCS group, 35% had a high to very high CERT2 score (7-12) when compared with 9% in the control group (P < 0.001). The CCS subgroup with a CERT2 score ≥ 7 had higher heart rate, systolic blood pressure, and higher levels of apolipoprotein B compared with CCS with a CERT2 score < 6 (P ≤ 0.011). When adjusted for age, sex, and BMI, CERT2 score was significantly correlated with arterial stiffness, growth hormone, and cranial radiotherapy (P < 0.044).

Conclusion

Ceramides could be important biomarkers in understanding the pathophysiology of CVD and in predicting CVD disease risk in young adult CCS.

Ceramides improve cardiovascular risk prediction beyond low-density lipoprotein cholesterol

Aims

Low-density lipoprotein cholesterol (LDL-C) is the best documented cardiovascular risk predictor and at the same time serves as a target for lipid-lowering therapy. However, the power of LDL-C to predict risk is biased by advanced age, comorbidities, and medical treatment, all known to impact cholesterol levels. Consequently, such biased patient cohorts often feature a U-shaped or inverse association between LDL-C and cardiovascular or overall mortality. It is not clear whether these constraints for risk prediction may likewise apply to other lipid risk markers in particular to ceramides and phosphatidylcholines.

Methods and results

In this observational cohort study, we recorded cardiovascular mortality in 1195 patients over a period of up to 16 years, comprising a total of 12 262 patient-years. The median age of patients at baseline was 67 years. All participants were either consecutively referred to elective coronary angiography or diagnosed with peripheral artery disease, indicating a high cardiovascular risk. At baseline, 51% of the patients were under statin therapy. We found a U-shaped association between LDL-C and cardiovascular mortality with a trough level of around 150 mg/dL of LDL-C. Cox regression analyses revealed that LDL-C and other cholesterol species failed to predict cardiovascular risk. In contrast, no U-shaped but linear association was found for ceramide- and phosphatidylcholine-containing markers and these markers were able to significantly predict the cardiovascular risk even after multivariate adjustment.

Conclusion

We thus suggest that ceramides- and phosphatidylcholine-based predictors rather than LDL-C may be used for a more accurate cardiovascular risk prediction in high-risk patients.

The Novel Ceramide- and Phosphatidylcholine-Based Risk Score for the Prediction of New-Onset of Hypertension

Ceramides and other sphingolipids are implicated in vascular dysfunction and inflammation. They have been suggested as potential biomarkers for hypertension. However, their specific association with hypertension prevalence and onset requires further investigation. This study aimed to identify specific ceramide and phosphatidylcholine species associated with hypertension prevalence and onset. The 2002 FINRISK (Finnish non-communicable risk factor survey) study investigated the association between coronary event risk scores (CERT1 and CERT2) and hypertension using prevalent and new-onset hypertension groups, both consisting of 7722 participants, over a span of 10 years. Ceramide and phosphatidylcholine levels were measured using tandem liquid chromatography-mass spectrometry. Ceramide and phosphatidylcholine ratios, including ceramide (d18:1/18:0), ceramide (d18:1/24:1), phosphatidylcholine (16:0/16:0), and the ratio of ceramide (d18:1/18:0)/(d18:1/16:0), are consistently associated with both prevalence and new-onset hypertension. Ceramide (d18:1/24:0) was also linked to both hypertension measures. Adjusting for covariates, CERT1 and CERT2 showed no-longer-significant associations with hypertension prevalence, but only CERT2 predicted new-onset hypertension. Plasma ceramides and phosphatidylcholines are crucial biomarkers for hypertension, with imbalances potentially contributing to its development. Further research is needed to understand the underlying mechanisms by which ceramides will contribute to the development of hypertension.

Short and medium chain acylcarnitines as markers of outcome in diabetic and non-diabetic subjects with acute coronary syndromes

BACKGROUND

Carnitine metabolism produces numerous molecular species of short-, medium-, and long-chain acylcarnitines, which play important roles in energy homeostasis and fatty acid transport in the myocardium. Given that disturbances in the carnitine metabolism are linked to cardiometabolic disease, we studied the relationship of circulating acylcarnitines with outcomes in patients with acute coronary syndromes (ACS) and evaluated differences in circulating levels of these metabolites between diabetic and non-diabetic patients.

METHODS

Harnessing a prospective multicentre cohort study (SPUM-ACS; NCT01000701), we measured plasma levels of acylcarnitines, carnitine, and carnitine metabolites to assess their relationship with adjudicated major adverse cardiac events (MACE), defined as composite of myocardial infarction, stroke, clinically indicated revascularization, or death of any cause. The SPUM-ACS study enrolled patients presenting with ACS to Swiss University Hospitals between 2009 and 2012. Acetylcarnitine, octanoylcarnitine, proprionylcarnitine, butyrylcarnitine, pentanoylcarnitine, hexanoylcarnitine, carnitine, γ-butyrobetaine, and trimethylamine N-oxide were measured in plasma using stable isotope dilution high-performance liquid chromatography with online electrospray ionization tandem mass spectrometry.

RESULTS

A total of 1683 patients with ACS were included in the study. All measured metabolites except γ-butyrobetaine and carnitine were higher in diabetic subject (n = 294) than in non-diabetic subjects (n = 1389). On univariate analysis, all metabolites, apart from octenoylcarnitine, were significantly associated with MACE at 1 year. After multivariable adjustment for established risk factors, acetylcarnitine remained an independent predictor of MACE at 1-year (quartile 4 vs. quartile 1, adjusted hazard ratio 2.06; 95% confidence interval 1.12-3.80, P = 0.020).

CONCLUSION

Circulating levels of acetylcarnitine independently predict residual cardiovascular risk in patients with ACS.

Coronary Event Risk Test (CERT) as a Risk Predictor for the 10-Year Clinical Outcome of Patients with Peripheral Artery Disease

(1) Background: Ceramides are a new kind of lipid biomarker and have already been demonstrated to be valuable risk predictors in coronary patients. Patients with peripheral artery disease (PAD) are a population with a worse prognosis and higher mortality risk compared to coronary artery disease (CAD) patients. However, the value of ceramides for risk prediction in PAD patients is still vague, as addressed in the present study. (2)Methods: This observational study included 379 PAD patients. The primary endpoint was all-cause mortality at 10 years of follow-up. A set of ceramides was measured by LC-MS/MS and combined according to the Coronary Event Risk Test (CERT) score, which categorizes patients into one of four risk groups (low risk, moderate risk, high risk, very high risk). (3) Results: Kaplan-Meier survival curves revealed that the overall survival of patients decreased with the increasing risk predicted by the four CERT categories, advancing from low risk to very high risk. Cox regression analysis demonstrated that each one-category increase resulted in a 35% rise in overall mortality risk (HR = 1.35 [1.16-1.58]). Multivariable adjustment, including, among others, age, LDL-cholesterol, type 2 diabetes, and statin treatment before the baseline, did not abrogate this significant association (HR = 1.22 [1.04-1.43]). Moreover, we found that the beneficial effect of statin treatment is significantly stronger in patients with a higher risk, according to CERT. (4) Conclusions: We conclude that the ceramide-based risk score CERT is a strong predictor of the 10-year mortality risk in patients with PAD.

Serum ceramides in early pregnancy as predictors of gestational diabetes

Ceramides contribute to the development of type 2 diabetes but it is uncertain whether they predict gestational diabetes (GDM). In this multicentre case-control study including 1040 women with GDM and 958 non-diabetic controls, early pregnancy (mean 10.7 gestational weeks) concentrations of four ceramides-Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0) and Cer(d18:1/24:1)-were determined by a validated mass-spectrometric method from biobanked serum samples. Traditional lipids including total cholesterol, LDL, HDL and triglycerides were measured. Logistic and linear regression and the LASSO logistic regression were used to analyse lipids and clinical risk factors in the prediction of GDM. The concentrations of four targeted ceramides and total cholesterol, LDL and triglycerides were higher and HDL was lower among women with subsequent GDM than among controls. After adjustments, Cer(d18:1/24:0), triglycerides and LDL were independent predictors of GDM, women in their highest quartile had 1.44-fold (95% CI 1.07-1.95), 2.17-fold (95% CI 1.57-3.00) and 1.63-fold (95% CI 1.19-2.24) odds for GDM when compared to their lowest quartiles, respectively. In the LASSO regression modelling ceramides did not appear to markedly improve the predictive performance for GDM alongside with clinical risk factors and triglycerides. However, their adverse alterations highlight the extent of metabolic disturbances involved in GDM.

Effect of Diets on Plasma and Aorta Lipidome: A Study in the apoE Knockout Mouse Model

SCOPE

Specific lipid molecules circulating in plasma at low concentrations have emerged as biomarkers of atherosclerotic risk. The aim of the present study is that of evaluating, in an athero-prone mouse model, how different diets can affect plasma and aorta lipidome.

METHODS AND RESULTS

Thirty-six apoE knockout mice are divided in three groups and feed 12 weeks with diets differing for cholesterol and fatty acid content. Atherosclerosis is measured at the aortic sinus and aorta. Lipids are quantified in plasma and aorta with mass spectrometry. The cholesterol content of the diets is the main driver of lipid accumulation in plasma and aorta. The fatty acid composition of the diets affects plasma levels both of essential (linoleic acid) and nonessential (myristic and arachidonic acid) ones. Lipidomics show a comparable distribution, in plasma and aorta, of the main lipid components of oxidized LDL, including cholesteryl esters and lysophosphatidylcholines. Interestingly, lactosylceramide, glucosyl/galactosylceramide, and individual ceramide species are found to accumulate in diseased aortic segments.

CONCLUSION

Both the cholesterol and fatty acid content of the diets profoundly affect plasma lipidome. Aorta lipidome is likewise affected with the accumulation of specific lipids known as markers of atherosclerosis.

Circulating trimethylamine N-oxide levels do not predict 10-year survival in patients with or without coronary heart disease

BACKGROUND

Trimethylamine N-oxide (TMAO) is an amine oxide generated by gut microbial metabolism. TMAO may contribute to atherothrombosis and systemic inflammation. However, the prognostic value of circulating TMAO for risk stratification is uncertain.

METHODS

We assessed prospective relationships of plasma TMAO with long-term risk of all-cause, cardiovascular (CV), and non-CV mortality in the Western Norway Coronary Angiography Cohort (WECAC; 4132 patients with suspected coronary artery disease) and the Hordaland Health Study (HUSK; 6393 community-based subjects). Risk associations were examined using Cox regression analyses.

RESULTS

Mean follow-up was 9.8 and 10.5 years in WECAC and HUSK, respectively. Following adjustments for established CV risk factors and indices of renal function in WECAC, the hazard ratios (HRs) (95% confidence intervals [CIs]) per one standard deviation increase in log-transformed plasma TMAO were 1.04 (0.97-1.12), 1.06 (0.95-1.18), and 1.03 (0.93-1.13) for all-cause, CV, and non-CV mortality, respectively. Essentially similar results were obtained in patients with angiographically significant coronary artery disease and patients with reduced left ventricular ejection fraction. Corresponding HRs (95% CIs) in the HUSK cohort were 1.03 (0.96-1.10), 1.01 (0.89-1.13), and 1.03 (0.95-1.12) for all-cause-, CV, and non-CV mortality, respectively.

CONCLUSIONS

Circulating TMAO did not predict long-term all-cause, CV, or non-CV mortality in patients with coronary heart disease or in community-based adults. This large study does not support a role of TMAO for patient risk stratification in primary or secondary prevention.

Ceramide-based lipid profiles and the prevalence of type 2 diabetes differ between patients with coronary artery disease and those with peripheral artery disease

Introduction

Serum lipids and metabolic diseases, in particular type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD), predict the atherosclerotic diseases coronary artery disease (CAD) and peripheral arterial disease (PAD).

Purpose

The purpose of this study was to investigate in how far a more detailed characterization including serum lipids improves discrimination of PAD from CAD.

Method

A cohort of 274 statin-naïve patients with either PAD (n=89) or stable CAD (n=185) were referred to metabolic screening and were characterized using nuclear magnetic resonance- and liquid chromatography-tandem mass spectrometry based advanced lipid and lipoprotein analysis. Results were validated in an independent cohort of 1239 patients with PAD or CAD.

Results

We found a significant difference in T2D prevalence and in the ceramide-based lipid profile between PAD and CAD patients. However, neither cholesterol-based markers (including LDL-C, HDL-C) and detailed lipoprotein profiles nor the LD status differed significantly between PAD and CAD patients (figure). The difference between ceramide-based lipid profiles of CAD and PAD remained significant also after adjusting for body composition, smoking, inflammatory parameters, and T2D.

Conclusion

We conclude that PAD and CAD differ in ceramide-based lipid profiles and T2D status, but not in other lipid characteristics or metabolic diseases.

Funding Acknowledgement

Type of funding sources: None.

Long-term prognostic value of trimethylamine N-oxide in community-based adults and patients with coronary heart disease

Background

Trimethylamine N-oxide (TMAO) is an amine oxide generated by gut microbial metabolism. Emerging evidence suggests pro-atherosclerotic and pro-inflammatory properties of TMAO; however, the clinical utility of circulating TMAO in risk stratification is uncertain.

Purpose

We prospectively assessed relationships of plasma TMAO with long-term risk of all-cause, cardiovascular (CV) and non-CV mortality in community-dwelling adults and patients with coronary heart disease.

Methods

By Cox modelling, risk-associations were examined in the Hordaland Health Study (HUSK; 6393 community-based adults) and the Western Norway Coronary Angiography Cohort (WECAC; 4132 patients with suspected chronic coronary syndrome).

Results

Median follow-up time was 11.0 and 10.3 years in HUSK and WECAC, respectively. Following adjustments for established CV risk factors in HUSK, the HRs (95% CIs) comparing the 4th vs. 1st TMAO-quartile were 1.11 (0.88–1.40), 0.97 (0.65–1.46) and 1.17 (0.88–1.54) for all-cause, CV and non-CV mortality, respectively. Corresponding risk estimates in WECAC were 1.07 (0.86–1.32), 1.16 (0.83–1.62) and 1.02 (0.77–1.34). Similar results were observed in patients with angiographically significant coronary artery disease and patients with reduced left ventricular ejection fraction.

Conclusion

Plasma TMAO was not predictive of long-term all-cause, CV or non-CV mortality in patients with or without established coronary heart disease. This large-scale study does not support a role of TMAO for patient risk stratification in primary or secondary prevention.

Funding Acknowledgement

Type of funding sources: None.

Plasma ceramides independently predict all-cause mortality in men aged 85

Background

assessing cardiovascular and mortality risk with conventional biomarkers is challenging in oldest-old due to multimorbidity and polypharmacy. Ceramides are bioactive lipids shown to predict mortality in late middle-aged cohorts.

Objective

to assess whether plasma ceramides have independent prognostic value for mortality among oldest-old (85+).

Design

longitudinal cohort study (Helsinki Businessmen Study, HBS) with a 3.5-year follow-up.

Setting and subjects

survivors of HBS (125 men born in 1919–1934) visited the clinic for laboratory and clinical examination.

Methods

functional status including physical (short physical performance battery) and Montreal Cognitive Assessment (MoCA) cognitive performance was assessed and laboratory examinations included a large set of biomarkers. Plasma ceramide concentration (Cer(d18:1/16:0)) was measured using a targeted liquid chromatography–tandem mass spectrometry assay. Mortality was retrieved from national registers.

Results

median age was 88 years, two-thirds had multimorbidity and 59% were on statin treatment. During the follow-up, 22 (18%) men died. In a model adjusted for variables associated with mortality in the whole cohort at P < 0.20 (log glucose, SPPB, MoCA and statin use), Cer(d18:1/16:0) as a continuous trait was associated with increased mortality: hazard ratio (HR) per 1 SD 1.64 (95% confidence interval [CI] 1.23–2.18). Compared with the bottom tertile of Cer(d18:1/16:0), HR of mortality was 5.44-fold (95% CI 1.17–25.3) in the top tertile.

Conclusions

these data raise the hypothesis that plasma ceramide concentrations and especially Cer(d18:1/1:60) may offer a clinically useful biomarker to evaluate prognosis in very old age. Such biomarkers are needed for geriatrics, where multimorbidity and pharmacotherapies, such as statins are prevalent hampering assessment of prognosis using conventional methods.

TNFα induces endothelial dysfunction in rheumatoid arthritis via LOX-1 and arginase 2: reversal by monoclonal TNFα antibodies

AIMS

Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting joints and blood vessels. Despite low levels of low-density lipoprotein cholesterol (LDL-C), RA patients exhibit endothelial dysfunction and are at increased risk of death from cardiovascular complications, but the molecular mechanism of action is unknown. We aimed in the present study to identify the molecular mechanism of endothelial dysfunction in a mouse model of RA and in patients with RA.

METHODS AND RESULTS

Endothelium-dependent relaxations to acetylcholine were reduced in aortae of two tumour necrosis factor alpha (TNFα) transgenic mouse lines with either mild (Tg3647) or severe (Tg197) forms of RA in a time- and severity-dependent fashion as assessed by organ chamber myograph. In Tg197, TNFα plasma levels were associated with severe endothelial dysfunction. LOX-1 receptor was markedly up-regulated leading to increased vascular oxLDL uptake and NFκB-mediated enhanced Arg2 expression via direct binding to its promoter resulting in reduced NO bioavailability and vascular cGMP levels as shown by ELISA and chromatin immunoprecipitation. Anti-TNFα treatment with infliximab normalized endothelial function together with LOX-1 and Arg2 serum levels in mice. In RA patients, soluble LOX-1 serum levels were also markedly increased and closely related to serum levels of C-reactive protein. Similarly, ARG2 serum levels were increased. Similarly, anti-TNFα treatment restored LOX-1 and ARG2 serum levels in RA patients.

CONCLUSIONS

Increased TNFα levels not only contribute to RA, but also to endothelial dysfunction by increasing vascular oxLDL content and activation of the LOX-1/NFκB/Arg2 pathway leading to reduced NO bioavailability and decreased cGMP levels. Anti-TNFα treatment improved both articular symptoms and endothelial function by reducing LOX-1, vascular oxLDL, and Arg2 levels.

Lipid profiles of patients with manifest coronary versus peripheral atherosclerosis - Is there a difference?

AIM

Peripheral arterial disease (PAD) and coronary artery disease (CAD) are both caused by atherosclerosis. Serum lipids and lipoproteins are predictive of the development of atherosclerosis but it is not clear if they differ in the two manifestations, PAD and CAD. We tested whether a more detailed characterization of the lipid and lipoprotein patterns of PAD and CAD allows a clear differentiation between the two atherosclerotic phenotypes.

METHODS

A cohort of 274 statin-naïve patients with either newly diagnosed imaging proven PAD (n = 89) or stable CAD (n = 185) was characterized using nuclear magnetic resonance- and liquid chromatography-tandem mass spectrometry-based advanced lipid and lipoprotein analysis. An independent cohort of 1239 patients with PAD and CAD was used for validation.

RESULTS

We found a significant difference in markers of inflammation as well as ceramide and phosphatidylcholine levels between patients with PAD and CAD. In contrast, basic lipid markers including total cholesterol, LDL cholesterol, HDL cholesterol, lipoprotein(a) or detailed lipoprotein profiles did not differ significantly between patients with PAD and CAD. Applying ratios and scores derived from ceramides and phosphatidylcholines further improved the discrimination between PAD and CAD. These significant differences were independent of body composition, from the status of smoking or type 2 diabetes mellitus, and also from apolipoprotein C-III and other inflammatory parameters which were different between CAD and PAD.

CONCLUSION

The present study clearly suggests that PAD and CAD differ in terms of their ceramide- and phosphatidylcholine-based lipid patterns but not in lipoprotein characteristics.

Absolute and relative risk prediction in cardiovascular primary prevention with a modified SCORE chart incorporating ceramide-phospholipid risk score and diabetes mellitus

Aims

A risk score, CERT2, based on distinct ceramide and phosphatidylcholine lipid species, has shown robust performance in predicting cardiovascular risk in secondary prevention. Here, our aim was to investigate the predictive value of CERT2 in primary prevention compared to classical lipid biomarkers and its compatibility with clinical characteristics used in the SCORE risk chart.

Methods and results

Four ceramides [Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0), Cer(d18:1/24:1)] and three phosphatidylcholines [PC(14:0/22:6), PC(16:0/22:5), PC(16:0/16:0)] were analysed by targeted tandem liquid chromatography–mass spectrometry method in FINRISK 2002, which is a population-based risk factor survey investigating men and women aged 25–74 years. Primary prevention subjects (N = 7324) were followed up for 10 years for the following outcomes: incident coronary heart disease (CHD), cardiovascular disease (CVD), major adverse cardiovascular event (MACE), stroke, and heart failure. Hazard ratios per standard deviation obtained from adjusted Cox proportional hazard models were significant for all these endpoints, and the highest for fatal ones, i.e. fatal CHD [1.45 (95% confidence interval 1.07–1.97)], CVD [1.39 (1.06–1.83)], and MACE [1.39 (1.07–1.80)]. The categorical net reclassification improvement was 0.051 for the 10-year risk of incident CVD. Incidence of fatal events was over 10-fold more frequent in the highest CERT2 category compared to the lowest risk category and modified SCORE risk charts, utilizing CERT2 and diabetes mellitus, increased granularity of risk assessment compared to a chart utilizing total cholesterol.

Conclusion

CERT2 is a significant predictor of incident cardiovascular outcomes and risk charts utilizing this score provide an easy tool to estimate relative and absolute risk for incident CVD.

The ceramide- and phosphatidylcholine- based Coronary Event Risk Test2 (CERT2) and cardiovascular mortality in men and women with type 2 diabetes

 

The recently introduced Coronary Event Risk Test version 2 (CERT2) is a validated cardiovascular risk predictor score that uses circulating ceramide and phosphatidylcholine concentrations.

The purpose of this study was to investigate the power of CERT2 to predict cardiovascular mortality in 280 male and 121 female patients with type 2 diabetes (T2DM).

Prospectively, we recorded 55 cardiovascular deaths in men and 19 in women during a mean follow-up time of 7.6±3.6 and 8.1±3.4 years respectively.

Overall, cardiovascular survival decreased with increasing CERT2 risk categories (figure 1). In Cox regression models, CERT2 significantly predicted the incidence of cardiovascular mortality in male patients with T2DM (unadj. HR 1.82 [1.39–2.37] per standard deviation; p&lt;0.001), the unadj. HR in women was 1.36 [0.83–2.22]; p=0.228). After adjustment for age, BMI, current smoking, LDL cholesterol, HDL cholesterol, hypertension, and statin use the HR in men was 1.73 [1.31–2.29]; p&lt;0.001) and 1.40 [083–2.36]; p=0.210 in women. Interaction terms CERT2 x gender were non-significant both in univariate analysis (p=0.354) and after multivariate adjustment (p=0.359).

We conclude that sex does not significantly impact the association of CERT2 with cardiovascular mortality in patients with T2DM.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Circulating trimethyllysine predicts total and cardiovascular mortality in patients with and without coronary heart disease

Background

The carnitine precursor trimethyllysine (TML) is associated with the microbiota-derived metabolite trimethylamine N-oxide (TMAO) and predicts future cardiovascular events in patients with established coronary heart disease (CHD).

Purpose

To examine circulating TML as a predictor of total and cardiovascular mortality in two independent cohorts of subjects with or without CHD.

Methods

By Cox regression modelling, risk associations were examined in 6393 subjects in the community-based Hordaland Health Study (HUSK). A replication study was performed among 4117 patients undergoing coronary angiography for suspected stable angina pectoris in the Western Norway Coronary Angiography Cohort (WECAC).

Results

During a median follow-up of 10.9 years in the HUSK-cohort, 884 (13.8%) subjects died, of whom 287 from cardiovascular causes. After adjustments for traditional cardiovascular risk factors, the hazard ratio (HR) (95% CI) for total mortality comparing the 4th vs. 1st TML-quartile was 1.66 (1.31–2.10, p&lt;0.001). Particularly strong associations were observed with cardiovascular mortality (HR [95% CI] 2.04 [1.32–3.15, p=0.001]). Corresponding risk estimates in the WECAC-cohort (median follow-up of 10.3 years) were 1.35 (1.10–1.66, p=0.004) for total and 1.45 (1.06–1.98, p=0.02) for cardiovascular mortality. Additional adjustments for plasma TMAO did not materially influence the risk estimates in either cohort, and no effect modification by TMAO was observed.

Conclusions

Circulating TML is associated with increased risk of total and cardiovascular mortality in both subjects with and without CHD.

Funding Acknowledgement

Type of funding sources: None.

Assessment of plasma ceramides as predictor for subclinical atherosclerosis

Background and aims

Ceramides have been identified as novel biomarkers for cardiovascular disease (CVD) related events and mortality but their role in etiology of subclinical atherosclerosis is unknown. We aimed to assess association between plasma ceramides and carotid intima-media thickness (CIMT) and evaluate predictive value of the ceramides for high CIMT over traditional CVD risk factors.

Methods

Association between plasma ceramides and CIMT in the Young Finns Study participants was analyzed with CIMT as outcome and ceramides along with traditional risk factors as predictors with regression model. Predictive value of the ceramides and related coronary event risk test (CERT) score for high CIMT as surrogate marker of subclinical atherosclerosis was assessed by comparing logistic regression-based prediction models including, i) traditional risk factors and ceramides, ii) traditional risk factors and CERT score, iii) age, sex and ceramides or alternatively CERT score with a reference model including only traditional risk factors. The prediction models were fitted to training data (70% data) and tested on test data (30% data). The predictive models were assessed with area under the receiver operating curve (AUC). The variance of AUC was estimated by repeating the model fitting and testing for 1000 bootstraps of the original data.

Results

Predictive models with plasma ceramides or alternatively with CERT score in addition to age and sex variables were able to predict high CIMT with AUC 0.726 and 0.720 respectively. However, the ceramides and CERT score did not have statistically significant added predictive value for high CIMT over traditional risk factors.

Conclusions

The new systemic biomarkers, high-risk plasma ceramides and CERT score, showed promising predictive performance for high CIMT with only age and sex as additional variables. This may help in predicting subclinical atherosclerosis for primary prevention.

Uncovering the shared lipidomic markers of subclinical osteoporosis-atherosclerosis comorbidity: The Young Finns Study

BACKGROUND

Osteoporosis and atherosclerosis are complex multifactorial diseases sharing common risk factors and pathophysiological mechanisms suggesting that these are comorbidities. Omics studies identifying joint molecular markers associated with these diseases are sparse.

SUBJECTS AND METHODS

Using liquid chromatography-tandem mass spectrometry, we quantified 437 molecular lipid species from the Young Finns Study cohort (aged 30-45 years and 57% women) and performed lipidome-wide multivariate analysis of variance (MANOVA) with early markers for both diseases. Carotid intima-media thickness for atherosclerosis measured with ultrasound and bone mineral density from distal radius and tibia for osteoporosis measured with peripheral quantitative computed tomography were used as early markers of the diseases.

RESULTS

MANOVA adjusted with age, sex and body mass index, identified eight statistically significant (adjusted p-value (p_adj) < 0.05) and 15 suggestively significant (p_adj < 0.25) molecular lipid species associated with the studied markers. Similar analysis adjusted additionally for smoking habit, physical activity and alcohol consumption identified four significant and six suggestively significant molecular lipid species. These most significant lipid classes/species jointly associated with the studied markers were glycerolipid/TAG(18:0/18:0/18:1), glycerophospholipid/PC(40:3), sphingolipid/Gb3(d18:1/22:0), and sphingolipid/Gb3(d18:1/24:0).

CONCLUSION

Our results support the osteoporosis-atherosclerosis comorbidity hypothesis and present potential new joint lipid biomarkers for these diseases.

Coffee, Atrial Fibrillation, and Circulating Ceramides in Patients with Chronic Heart Failure

Ceramides are sphingolipids that play roles as structural lipids and as second messengers in biological processes. Circulating ceramides are influenced by diet/food and predict major cardiovascular (CV) events, such as atrial fibrillation (AF). In 1227 patients with symptomatic chronic heart failure (HF), an association between diet and ceramides was found for coffee consumption of ≥3 cups and Cer(d18:1/24:0). Increased Cer(d18:1/24:0) was associated with lower incident AF (24.3% vs 15.4% tertile 1 vs 3, P = 0.016) and lower CV mortality (28.4% vs 12.0% tertile 1 vs 3, P < 0.0001). For coffee consumption, only an association with incident AF was found (24.5% never, 5.2% ≥3 cups). These inverse associations with AF were confirmed in survival analyses corrected for biomarkers (Cer(d18:1/24:0) HR: 0.79, P = 0.018; coffee consumption HR: 0.22, P = 0.001). In conclusion, higher coffee intake was associated with a lower risk of incident AF and with higher concentrations of Cer(d18:1/24:0). Cer(d18:1/24:0) was inversely associated to risk of AF.

A Randomized Controlled Dietary Intervention Improved the Serum Lipid Signature towards a Less Atherogenic Profile in Patients with Rheumatoid Arthritis

Diet is a major modifiable risk factor for cardiovascular disease (CVD). One explanation for this is its effect on specific lipids. However, knowledge on how the lipidome is affected is limited. We aimed to investigate if diet can change the new ceramide- and phospholipid-based CVD risk score CERT2 and the serum lipidome towards a more favorable CVD signature. In a crossover trial (ADIRA), 50 patients with rheumatoid arthritis (RA) had 10 weeks of a Mediterranean-style diet intervention or a Western-style control diet and then switched diets after a 4-month wash-out-period. Five hundred and thirty-eight individual lipids were measured in serum by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Lipid risk scores were analyzed by Wilcoxon signed-rank test or mixed model and lipidomic data with multivariate statistical methods. In the main analysis, including the 46 participants completing ≥1 diet period, there was no significant difference in CERT2 after the intervention compared with the control, although several CERT2 components were changed within periods. In addition, triacylglycerols, cholesteryl esters, phosphatidylcholines, alkylphosphatidylcholines and alkenylphosphatidylcholines had a healthier composition after the intervention compared to after the control diet. This trial indicates that certain dietary changes can improve the serum lipid signature towards a less atherogenic profile in patients with RA.

Comparison of recent ceramide-based coronary risk prediction scores in cardiovascular disease patients

AIM

Cholesterol-based risk prediction is often insufficient in cardiovascular disease (CVD) patients. Ceramides are a new kind of biomarkers for CVD. The Coronary Event Risk Test (CERT) is a validated cardiovascular risk predictor that uses only circulating ceramide levels, determined by coupled liquid chromatography-mass spectrometry, to allocate patients into one of four risk categories. This test has recently been modified (CERT2) by additionally including phosphatidylcholine levels.

METHODS AND RESULTS

In this observational cohort study, we have recruited 999 Austrian patients with CVD and followed them for up to 13 years. We found that CERT and CERT2 both predicted cardiovascular events, cardiovascular mortality, and overall mortality. CERT2 had the higher performance compared to CERT and also to the recent cardiovascular risk score of the ESC/EAS guidelines (Systematic COronary Risk Evaluation (SCORE)) for low-risk European countries. Combining CERT2 with the ESC/EAS-SCORE, predictive capacity was further increased leading to a hazard ratio of 3.58 (2.02-6.36; P < 0.001) for cardiovascular events, 11.60 (2.72-49.56; P = 0.001) for cardiovascular mortality, and 9.86 (4.23-22.99; P < 0.001) for overall mortality when patients with very high risk (category 4) were compared to those with low risk (category 1). The use of the combined score instead of the ESC/EAS-SCORE significantly improved the predictive power according to the integrated discrimination improvement index (P = 0.004).

CONCLUSION

We conclude that CERT and CERT2 are powerful predictors of cardiovascular events, cardiovascular mortality, and overall mortality in CVD patients. Including phosphatidylcholine to a ceramide-based score increases the predictive performance and is best in combination with classical risk factors as used in the ESC/EAS-SCORE.

Trimethyllysine predicts all-cause and cardiovascular mortality in community-dwelling adults and patients with coronary heart disease

Aims

Trimethyllysine (TML) is involved in carnitine synthesis, serves as a precursor of trimethylamine N-oxide (TMAO) and is associated with cardiovascular events in patients with established coronary heart disease (CHD). We prospectively examined circulating TML as a predictor of all-cause and cardiovascular mortality in community-dwelling adults and patients with CHD.

Methods and results

By Cox regression modelling, risk associations were examined in 6393 subjects in the community-based Hordaland Health Study (HUSK). A replication study was conducted among 4117 patients with suspected stable angina pectoris in the Western Norway Coronary Angiography Cohort (WECAC). During a mean follow-up of 10.5 years in the HUSK-cohort, 884 (13.8%) subjects died, of whom 287 from cardiovascular causes. After multivariable adjustments for traditional cardiovascular risk factors, the hazard ratio (HR) [95% confidence interval (95% CI)] for all-cause mortality comparing the 4th vs. 1st TML-quartile was 1.66 (1.31–2.10, P < 0.001). Particularly strong associations were observed for cardiovascular mortality [HR (95% CI) 2.04 (1.32–3.15, P = 0.001)]. Corresponding risk-estimates in the WECAC (mean follow-up of 9.8 years) were 1.35 [1.10–1.66, P = 0.004] for all-cause and 1.45 [1.06–1.98, P = 0.02] for cardiovascular mortality. Significant correlations between plasma TML and TMAO were observed in both cohorts (r_s ≥ 0.42, P < 0.001); however, additional adjustments for TMAO did not materially influence the risk associations, and no effect modification by TMAO was found.

Conclusions

Elevated TML-levels were associated with increased risk of all-cause and cardiovascular mortality both in subjects with and without established CHD.

Primary cardiovascular risk prediction by LDL-cholesterol in Caucasian middle-aged and older adults: a joint analysis of three cohorts

AIMS

Low-density lipoprotein cholesterol (LDL-C) is an established causal driver of atherosclerotic cardiovascular disease (ASCVD), but its performance and age-dependency as a biomarker for incident events and mortality arising from ASCVD is less clear. The aim was to determine the value of LDL-C as a susceptibility/risk biomarker for incident coronary heart disease (CHD), ASCVD, and stroke events and deaths, for the age groups <50 and ≥50 years.

METHODS AND RESULTS

The performance of LDL-C was evaluated in three cohorts, FINRISK 2002 (n = 7709), HUSK (n = 5431), and ESTHER (n = 4559), by Cox proportional hazards models, C-statistics, and net reclassification index calculations. Additionally, the hazard ratios (HRs) for the three cohorts were pooled by meta-analysis. The most consistent association was observed for CHD [95% confidence interval (CI) for HRs per standard deviation ranging from 0.99 to 1.37], whereas the results were more modest for ASCVD (0.96-1.18) due to lack of association with stroke (0.77-1.24). The association and discriminatory value of LDL-C with all endpoints in FINRISK 2002 and HUSK were attenuated in subjects 50 years and older [HRs (95% CI) obtained from meta-analysis 1.11 (1.04-1.18) for CHD, 1.15 (1.02-1.29) for CHD death, 1.02 (0.98-1.06) for ASCVD, 1.12 (1.02-1.23) for ASCVD death, and 0.97 (0.89-1.05) for stroke].

CONCLUSION

In middle-aged and older adults, associations between LDL-C and all the studied cardiovascular endpoints were relatively weak, while LDL-C showed stronger association with rare events of pre-mature CHD or ASCVD death among middle-aged adults. The predictive performance of LDL-C also depends on the studied cardiovascular endpoint.

Improving 1-year mortality prediction in ACS patients using machine learning

BACKGROUND

The Global Registry of Acute Coronary Events (GRACE) score is an established clinical risk stratification tool for patients with acute coronary syndromes (ACS). We developed and internally validated a model for 1-year all-cause mortality prediction in ACS patients.

METHODS

Between 2009 and 2012, 2'168 ACS patients were enrolled into the Swiss SPUM-ACS Cohort. Biomarkers were determined in 1'892 patients and follow-up was achieved in 95.8% of patients. 1-year all-cause mortality was 4.3% (n = 80). In our analysis we consider all linear models using combinations of 8 out of 56 variables to predict 1-year all-cause mortality and to derive a variable ranking.

RESULTS

1.3% of 1'420'494'075 models outperformed the GRACE 2.0 Score. The SPUM-ACS Score includes age, plasma glucose, NT-proBNP, left ventricular ejection fraction (LVEF), Killip class, history of peripheral artery disease (PAD), malignancy, and cardio-pulmonary resuscitation. For predicting 1-year mortality after ACS, the SPUM-ACS Score outperformed the GRACE 2.0 Score which achieves a 5-fold cross-validated AUC of 0.81 (95% CI 0.78-0.84). Ranking individual features according to their importance across all multivariate models revealed age, trimethylamine N-oxide, creatinine, history of PAD or malignancy, LVEF, and haemoglobin as the most relevant variables for predicting 1-year mortality.

CONCLUSIONS

The variable ranking and the selection for the SPUM-ACS Score highlight the relevance of age, markers of heart failure, and comorbidities for prediction of all-cause death. Before application, this score needs to be externally validated and refined in larger cohorts.

CLINICAL TRIAL REGISTRATION

NCT01000701.

Development and validation of a ceramide- and phospholipid-based cardiovascular risk estimation score for coronary artery disease patients

AIMS

Distinct ceramide lipids have been shown to predict the risk for cardiovascular disease (CVD) events, especially cardiovascular death. As phospholipids have also been linked with CVD risk, we investigated whether the combination of ceramides with phosphatidylcholines (PCs) would be synergistic in the prediction of CVD events in patients with atherosclerotic coronary heart disease in three independent cohort studies.

METHODS AND RESULTS

Ceramides and PCs were analysed using liquid chromatography-mass spectrometry (LC-MS) in three studies: WECAC (The Western Norway Coronary Angiography Cohort) (N = 3789), LIPID (Long-Term Intervention with Pravastatin in Ischaemic Disease) trial (N = 5991), and KAROLA (Langzeiterfolge der KARdiOLogischen Anschlussheilbehandlung) (N = 1023). A simple risk score, based on the ceramides and PCs showing the best prognostic features, was developed in the WECAC study and validated in the two other cohorts. This score was highly significant in predicting CVD mortality [multiadjusted hazard ratios (HRs; 95% confidence interval) per standard deviation were 1.44 (1.28-1.63) in WECAC, 1.47 (1.34-1.61) in the LIPID trial, and 1.69 (1.31-2.17) in KAROLA]. In addition, a combination of the risk score with high-sensitivity troponin T increased the HRs to 1.63 (1.44-1.85) and 2.04 (1.57-2.64) in WECAC and KAROLA cohorts, respectively. The C-statistics in WECAC for the risk score combined with sex and age was 0.76 for CVD death. The ceramide-phospholipid risk score showed comparable and synergistic predictive performance with previously published CVD risk models for secondary prevention.

CONCLUSION

A simple ceramide- and phospholipid-based risk score can efficiently predict residual CVD event risk in patients with coronary artery disease.

Plasma ceramide and phospholipid-based risk score and the risk of cardiovascular death in patients after acute coronary syndrome

Aims

Ceramide (Cer) and phosphatidylcholine (PC) lipids are associated with pathophysiological processes in cardiovascular (CV) diseases. A previously derived and validated plasma Cer-PC risk score (CERT2) was associated with CV death risk in patients with stable disease, but its prognostic value has not been evaluated in patients early post-acute coronary syndrome (ACS).

Methods and results

Prespecified plasma Cer and PC species of CERT2 risk score were measured in 4871 subjects from SOLID-TIMI 52, which enrolled patients ≤30 days after ACS (median follow-up 2.5 years). The CERT2 score (scale 0–12 points) was calculated as previously defined. The primary outcome was CV death; CV death or heart failure (HF) hospitalization (HF), myocardial infarction (MI), stroke, and all-cause death were also analysed. Poisson models included baseline characteristics and established biomarkers. Patients with higher CERT2 risk scores were more likely to be older, female, current smokers, presenting with STEMI, and to have impaired renal function and higher LDL-C. After multivariable adjustment, patients in the highest risk score category remained at a nearly two-fold higher risk of CV death (adj relative risk [RR] 1.92, 95% CI 1.01–3.66, P = 0.047). Patients in the highest risk score category were also at higher risk of all-cause death (adj RR 2.01, 95% CI 1.21–3.35, P = 0.007), whereas the relationships with HF, MI, and stroke were attenuated with multivariable adjustment.

Conclusions

A plasma ceramide and phospholipid-based risk score are associated with the risk of CV death independent of established clinical risk factors and biomarkers in patients after ACS.

Comparison of two recent ceramide-based coronary risk prediction scores: CERT and CERT-2

 

The Coronary Event Risk Test (CERT) is a validated cardiovascular risk predictor that uses circulating ceramide concentrations to allocate patients into one of four risk categories. This test has recently been updated (CERT-2), now additionally including phosphatidylcholine concentrations.

The purpose of this study was to investigate the power of CERT and CERT-2 to predict cardiovascular mortality in patients with cardiovascular disease (CVD).

We investigated a cohort of 999 patients with established CVD.

Overall, comparing survival curves (figure) for over 12 years of follow up and the predictive power of survival models using net reclassification improvement (NRI), CERT-2 was the best predictor of cardiovascular mortality, surpassing CERT (NRI=0.456; p=0.01) and also the 2019 ESC-SCORE (NRI=0.163; p=0.04). Patients in the highest risk category of CERT as compared to the lowest category had a HR of 3.63 [2.09–6.30] for cardiovascular death; for CERT-2 the corresponding HR was 6.02 [2.47–14.64]. Among patients with T2DM (n=322), the HR for cardiovascular death was 3.00 [1.44–6.23] using CERT and 7.06 [1.64–30.50] using CERT-2; the corresponding HRs among non-diabetic subjects were 2.99 [1.20–7.46] and 3.43 [1.03–11.43], respectively.

We conclude that both, CERT and CERT-2 scores are powerful predictors of cardiovascular mortality in CVD patients, especially in those patients with T2D. Performance is even higher with CERT-2.

Funding Acknowledgement

Type of funding source: None

Ceramides improve atherosclerotic cardiovascular disease risk assessment beyond standard risk factors

Ceramides are bioactive lipids that act as secondary messengers for both intra- and inter-cellular signaling. Elevated plasma concentrations of ceramides are associated with multiple risk factors of atherosclerotic cardiovascular diseases and comorbidities including obesity, insulin resistance and diabetes mellitus. Furthermore, atherosclerotic plaques have been shown to be highly enriched with ceramides. Increases in ceramide content may accelerate atherosclerosis development by promoting LDL infiltration to the endothelium and aggregation within the intima of artery walls. Thus, ceramides appear to play a key role in the development of cardiometabolic disease due to their central location in major metabolic pathways that intersect lipid and glucose metabolism. Recently published data have shown that ceramides are not only of scientific interest but may also have diagnostic value. Their independent prognostic value for future cardiovascular outcomes over and above LDL cholesterol and other traditional risk factors have consistently been shown in numerous clinical studies. Thus, ceramide testing with a mass spectrometer offers a simple, reproducible and cost-effective blood test for risk stratification in atherosclerotic cardiovascular diseases.

Different rates of flux through the biosynthetic pathway for long-chain versus very-long-chain sphingolipids

The backbone of all sphingolipids (SLs) is a sphingoid long-chain base (LCB) to which a fatty acid is N-acylated. Considerable variability exists in the chain length and degree of saturation of both of these hydrophobic chains, and recent work has implicated ceramides with different LCBs and N-acyl chains in distinct biological processes; moreover, they may play different roles in disease states and possibly even act as prognostic markers. We now demonstrate that the half-life, or turnover rate, of ceramides containing diverse N-acyl chains is different. By means of a pulse-labeling protocol using stable-isotope, deuterated free fatty acids, and following their incorporation into ceramide and downstream SLs, we show that very-long-chain (VLC) ceramides containing C24:0 or C24:1 fatty acids turn over much more rapidly than long-chain (LC) ceramides containing C16:0 or C18:0 fatty acids due to the more rapid metabolism of the former into VLC sphingomyelin and VLC hexosylceramide. In contrast, d16:1 and d18:1 ceramides show similar rates of turnover, indicating that the length of the sphingoid LCB does not influence the flux of ceramides through the biosynthetic pathway. Together, these data demonstrate that the N-acyl chain length of SLs may not only affect membrane biophysical properties but also influence the rate of metabolism of SLs so as to regulate their levels and perhaps their biological functions.

Prediction of Residual Risk by Ceramide-Phospholipid Score in Patients With Stable Coronary Heart Disease on Optimal Medical Therapy

Background

Identification of patients with stable coronary heart disease who are at significant residual risk could be helpful for targeted prevention. Our aim was to determine the prognostic value of the recently introduced ceramide‐ and phospholipid‐based risk score, the Cardiovascular Event Risk Test (CERT2), in patients with stable coronary heart disease on optimal medical therapy and to identify biological processes that contribute to the CERT2 score.

Methods and Results

Plasma samples (n=11 222) obtained from the STABILITY (Stabilization of Atherosclerotic Plaque by Initiation of Darapladib Therapy) trial were analyzed using a tandem liquid chromatography‐mass spectrometry method. STABILITY was a trial in patients with stable coronary heart disease randomized to the lipoprotein‐associated phospholipase A2 inhibitor darapladib or placebo on optimized medical therapy at baseline, with a median follow‐up of 3.7 years. Hazard ratios per SD for the CERT2 risk score were 1.32 (95% CI, 1.25–1.39) for major adverse cardiovascular event, 1.47 (95% CI, 1.35–1.59) for cardiovascular death, 1.32 (95% CI, 1.16–1.49) for stroke, 1.23 (95% CI, 1.14–1.33) for myocardial infarction, and 1.56 (95% CI, 1.39–1.76) for hospitalization due to heart failure, when adjusted for traditional cardiovascular risk factors. CERT2 showed correlation (P<0.001, r>0.2) with inflammatory markers high‐sensitivity C‐reactive protein, interleukin 6, the heart failure marker N‐terminal pro‐B‐type natriuretic peptide, and low‐density lipoprotein cholesterol. After also adjusting for levels of other prognostic biomarkers, the CERT2 score was still independently related to the risk of cardiovascular death but not to nonfatal events.

Conclusions

The CERT2 risk score can detect residual risk in patients with stable coronary heart disease and is associated with biomarkers indicating inflammation, myocardial necrosis, myocardial dysfunction, renal dysfunction, and dyslipidemia.

REGISTRATION

URL: https://www.clini​caltr​ials.gov. Unique identifier: NCT00799903.

Association between increased plasma ceramides and chronic kidney disease in patients with and without ischemic heart disease

AIM

Plasma levels of certain ceramides are increased in patients with ischemic heart disease (IHD). Many risk factors for IHD are also risk factors for chronic kidney disease (CKD), but it is currently uncertain whether plasma ceramide levels are increased in patients with CKD.

METHODS

We measured six previously identified high-risk plasma ceramide concentrations [Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/20:0), Cer(d18:1/22:0), Cer(d18:1/24:0) and Cer(d18:1/24:1)] in 415 middle-aged individuals who attended our clinical Cardiology and Diabetes services over a period of 9 months.

RESULTS

A total of 97 patients had CKD (defined as e-GFR_CKD-EPI<60ml/min/1.73m² and/or urinary albumin-to-creatinine ratio≥30mg/g), 117 had established IHD and 242 had type 2 diabetes. Patients with CKD had significantly (P=0.005 or less) higher levels of plasma Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/20:0), Cer(d18:1/22:0), Cer(d18:1/24:0), and Cer(d18:1/24:1) compared to those without CKD. The presence of CKD remained significantly associated with higher levels of plasma ceramides (standardized beta coefficients ranging from 0.124 to 0.227, P<0.001) even after adjustment for body mass index, smoking, hypertension, diabetes, prior IHD, plasma LDL-cholesterol, hs-C-reactive protein levels and use of any lipid-lowering medications. Notably, more advanced stages of CKD and abnormal albuminuria were both associated (independently of each other) with increased levels of plasma ceramides. These results were consistent in all subgroups considered, including patients with and without established IHD or those with and without diabetes.

CONCLUSION

Increased levels of plasma ceramides are associated with CKD independently of pre-existing IHD, diabetes and other established cardiovascular risk factors.

Lipidomic architecture shared by subclinical markers of osteoporosis and atherosclerosis: The Cardiovascular Risk in Young Finns Study

BACKGROUND

Studies have shown that osteoporosis and atherosclerosis are comorbid conditions sharing common risk factors and pathophysiological mechanisms. Understanding these is crucial in order to develop shared methods for risk stratification, prevention, diagnosis and treatment. The aim of this study was to apply a system-level bioinformatics approach to lipidome-wide data in order to pinpoint the lipidomic architecture jointly associated with surrogate markers of these complex comorbid diseases.

SUBJECTS AND METHODS

The study was based on the Cardiovascular Risk in Young Finns Study cohort from the 2007 follow-up (n = 1494, aged 30-45 years, women: 57%). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyse the serum lipidome, involving 437 molecular lipid species. The subclinical osteoporotic markers included indices of bone mineral density and content, measured using peripheral quantitative computer tomography from the distal and shaft sites of both the tibia and the radius. The subclinical atherosclerotic markers included carotid and bulbus intima media thickness measured with high-resolution ultrasound. Weighted co-expression network analysis was performed to identify networks of densely interconnected lipid species (i.e. lipid modules) associated with subclinical markers of both osteoporosis and atherosclerosis. The levels of lipid species (lipid profiles) of each of the lipid modules were summarized by the first principal component termed as module eigenlipid. Then, Pearson's correlation (r) was calculated between the module eigenlipids and the markers. Lipid modules that were significantly and jointly correlated with subclinical markers of both osteoporosis and atherosclerosis were considered to be related to the comorbidities. The hypothesis that the eigenlipids and profiles of the constituent lipid species in the modules have joint effects on the markers was tested with multivariate analysis of variance (MANOVA).

RESULTS

Among twelve studied molecular lipid modules, we identified one module with 105 lipid species significantly and jointly associated with both subclinical markers of both osteoporosis (r = 0.24, p-value = 2 × 10^-20) and atherosclerosis (r = 0.16, p-value = 2 × 10^-10). The majority of the lipid species in this module belonged to the glycerolipid (n = 60), glycerophospholipid (n = 13) and sphingolipid (n = 29) classes. The module was also enriched with ceramides (n = 20), confirming their significance in cardiovascular outcomes and suggesting their joint role in the comorbidities. The top three of the 37 statistically significant (adjusted p-value < 0.05) lipid species jointly associated with subclinical markers of both osteoporosis and atherosclerosis within the module were all triacylglycerols (TAGs) - TAG(18:0/18:0/18:1) with an adjusted p-value of 8.6 × 10^-8, TAG(18:0/18:1/18:1) with an adjusted p-value of 3.7 × 10^-6, and TAG(16:0/18:0/18:1) with an adjusted p-value of 8.5 × 10^-6.

CONCLUSION

This study identified a novel lipid module associated with both surrogate markers of both subclinical osteoporosis and subclinical atherosclerosis. Alterations in the metabolism of the identified lipid module and, more specifically, the TAG related molecular lipids within the module may provide potential new biomarkers for testing the comorbidities, opening avenues for the emergence of dual-purpose prevention measures.

Ceramides and Ceramide Scores: Clinical Applications for Cardiometabolic Risk Stratification

Ceramides are bioactive lipids that have an important role in many cellular functions such as apoptosis and inflammation. During the past decade emerging clinical data have shown that ceramides are not only of great biochemical interest but may also have diagnostic utility. Ceramides have shown independent predictive value for negative cardiovascular outcomes as well as for the onset of type 2 diabetes. Based on abundant published data, risk score using the concentrations of circulating ceramides have been developed and adapted for routine clinical practice. Currently serum ceramides are used clinically as efficient risk stratifiers for primary and secondary prevention of atherosclerotic cardiovascular disease (CVD). A direct cause-effect relationship between CVD and ceramide has not been established to date. As ceramide-specific medications are being developed, conventional strategies such as lipid lowering agents and lifestyle interventions can be used to reduce overall risk. Ceramides can identify a very high-risk coronary heart disease category of patients in need for more intense medical attention, specifically those patients at higher risk as highlighted in the 2019 European Society of Cardiology guidelines for stable chronic coronary syndrome patients. In addition, the ceramide risk score may be used as a decision-making tool in primary prevention patients with moderate CVD risk. Finally, the ceramide risk score may have a unique utility as a motivational tool to increase patient's adherence to medical therapy and lifestyle changes.

Susceptibility of low-density lipoprotein particles to aggregate depends on particle lipidome, is modifiable, and associates with future cardiovascular deaths

Aims

Low-density lipoprotein (LDL) particles cause atherosclerotic cardiovascular disease (ASCVD) through their retention, modification, and accumulation within the arterial intima. High plasma concentrations of LDL drive this disease, but LDL quality may also contribute. Here, we focused on the intrinsic propensity of LDL to aggregate upon modification. We examined whether inter-individual differences in this quality are linked with LDL lipid composition and coronary artery disease (CAD) death, and basic mechanisms for plaque growth and destabilization.

Methods and results

We developed a novel, reproducible method to assess the susceptibility of LDL particles to aggregate during lipolysis induced ex vivo by human recombinant secretory sphingomyelinase. Among patients with an established CAD, we found that the presence of aggregation-prone LDL was predictive of future cardiovascular deaths, independently of conventional risk factors. Aggregation-prone LDL contained more sphingolipids and less phosphatidylcholines than did aggregation-resistant LDL. Three interventions in animal models to rationally alter LDL composition lowered its susceptibility to aggregate and slowed atherosclerosis. Similar compositional changes induced in humans by PCSK9 inhibition or healthy diet also lowered LDL aggregation susceptibility. Aggregated LDL in vitro activated macrophages and T cells, two key cell types involved in plaque progression and rupture.

Conclusion

Our results identify the susceptibility of LDL to aggregate as a novel measurable and modifiable factor in the progression of human ASCVD.

Fenretinide treatment accelerates atherosclerosis development in apoE-deficient mice in spite of beneficial metabolic effects

BACKGROUND AND PURPOSE

Fenretinide, a synthetic retinoid derivative first investigated for cancer prevention and treatment, has been shown to ameliorate glucose tolerance, improve plasma lipid profile and reduce body fat mass. These effects, together with its ability to inhibit ceramide synthesis, suggest that fenretinide may have an anti-atherosclerotic action.

EXPERIMENTAL APPROACH

To this aim, nine-week-old apoE-knockout (EKO) female mice were fed for twelve weeks a Western diet, without (control) or with (0.1% w/w) fenretinide. As a reference, wild-type (WT) mice were treated similarly. Growth and metabolic parameters were monitored throughout the study. Atherosclerosis development was evaluated in the aorta and at the aortic sinus. Blood and lymphoid organs were further characterized with thorough cytological/histological and immunocytofluorimetric analyses.

KEY RESULTS

Fenretinide treatment significantly lowered body weight, glucose levels and plasma levels of total cholesterol, triglycerides, and phospholipids. In the liver, fenretinide remarkably reduced hepatic glycogenosis and steatosis driven by the Western diet. Treated spleens were abnormally enlarged, with severe follicular atrophy and massive extramedullary haematopoiesis. Severe renal hemosiderin deposition was observed in treated EKO mice. Treatment resulted in a threefold increase of total leukocytes (WT and EKO) and raised the activated/resting monocyte ratio in EKO mice. Finally, atherosclerosis development was markedly increased at the aortic arch, thoracic and abdominal aorta of fenretinide-treated mice.

CONCLUSIONS AND IMPLICATIONS

We provide the first evidence that, despite beneficial metabolic effects, fenretinide treatment may enhance the development of atherosclerosis.

P3640Association of ceramide and phospholipid levels and cardiovascular events in stable coronary heart disease: findings from the STABILITY Biomarkers substudy

Background

Both levels of protein and lipid biomarkers have been found associated with cardiovascular outcomes in patients with stable coronary heart disease (CHD). There are few large-scale studies comparing the prognostic value of and interactions between these two groups of biomarkers in CHD.

Methods

In the 15,828 CHD patients included in the STABILITY trial 10,205 provided plasma samples at baseline allowing measurements of distinct ceramide and phospholipid species by mass spectrometry and markers of cardiac dysfunction (N-terminal pro-B-type natriuretic peptide [NT-proBNP]), high sensitivity cardiac troponin-T [cTnT-hs]), renal dysfunction (cystatin-C), oxidative stress (growth differentiation factor 15 [GDF-15]) by electro-immunoassays. During 3.7 years median follow-up, 1291 CVD, MI, and stroke events occurred. A previously developed ceramide and phospholipid species based risk score (CERT) and its associations to outcomes before and after adjustment were evaluated by Cox-regression models.

Results

The CERT model was significantly associated to all cardiovascular outcomes before and after adjustment for clinical characteristics and routine laboratory tests. However, the associations were attenuated after adjustment for other prognostic biomarkers. The data are summarized in Table 1 below.

Table 1. HR per 1 SD increase in CERT HR (95% CI) p-value MACE Model 1 1.30 (1.24–1.37) <0.0001 Model 2 1.23 (1.16–1.31) <0.0001 Model 3 1.08 (1.02–1.15) 0.0120 CVD Death Model 1 1.57 (1.45–1.69) <0.0001 Model 2 1.38 (1.26–1.50) <0.0001 Model 3 1.14 (1.04–1.26) 0.0052 MACE = CVD death, stroke and MI. Model 1 includes score and randomized treatment. Model 2 includes score, randomized treatment, age, gender, and prior (MI, coronary revas., multivessel CHD), B/L diabetes, hypertension, history of smoking, PVD, region, B/L systolic BP, B/L BMI, HB, WBC, CKD-EPI, LDL-C, HDL-C and TG. Model 3 includes the following covariates in addition to Model 2: TnT-hs, proBNP, Cystatin-C, CRP-hs and IL-6.

Conclusion

A ceramide/phospholipids based risk score is associated with the risk of fatal and non-fatal cardiovascular events in patients with stable CHD. The score is attenuated by adjustment for biomarkers indicating cardiorenal dysfunction and inflammatory activity and may be related to underlying mechanisms for adverse outcomes in stable CHD.

Acknowledgement/Funding

The original STABILITY study was funded by GlaxoSmithKline

P4992The ceramide-based Coronary Event Risk Test (CERT) predicts cardiovascular mortality in cardiovascular disease patients with type 2 diabetes mellitus as well as in those without diabetes

Background

The recently introduced Coronary Event Risk Test (CERT) is a validated cardiovascular risk predictor that uses circulating ceramide concentrations to allocate patients into one of four risk categories.

Purpose

The purpose of this study was to investigate the power of CERT to predict cardiovascular mortality in patients with established cardiovascular disease (CVD) including patients with type 2 diabetes (T2DM).

Methods

We investigated a total of 1087 patients with established CVD, including 360 patients with T2DM.

At baseline, the prevalence of T2DM increased through CERT categories (29.1, 31.1, 37.4, and 53.4%, respectively, ptrend<0.001). Prospectively, cardiovascular deaths were recorded during a mean follow-up time of 8.1±3.2 years.

Results

A total of 130 cardiovascular deaths occurred. Overall, cardiovascular mortality increased with increasing CERT categories (figure) and was higher in T2DM patients than in those who did not have diabetes (17.7 vs. 9.4%; p<0.001). In Cox regression models, CERT categories predicted cardiovascular mortality in patients with T2DM (unadjusted HR 1.60 [1.28–2.01]; p<0.001; HR adjusted for age, gender, BMI, smoking, LDL cholesterol, HDL cholesterol, hypertension, and statin use 1.65 [1.27–2.15]; p<0.001) and in those without diabetes (unadjusted HR 1.43 [1.10–1.85]; p=0.008 and adjusted HR 1.41 [1.07–1.85]; p=0.015).

Cardiovascular survival of CVD patients

Conclusion

We conclude that CERT predicts cardiovascular mortality in CVD patients with T2DM as well as in those without diabetes.

P4497Serum ceramides and type 2 diabetes are mutually independent predictors of cardiovascular events in patients with peripheral artery disease

Background

Ceramides are enriched in atherosclerotic plaques, and a set of circulating ceramides including Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:1), and Cer(d18:1/24:0) has recently emerged as predictors of cardiovascular outcomes in coronary artery disease patients.

Purpose

The purpose of this study was to investigate their power to predict cardiovascular events in patients with peripheral artery disease (PAD).

Methods

We measured the serum concentrations of the above mentioned ceramides in a cohort of 380 patients with sonographically proven PAD, of whom 107 had type 2 diabetes (T2DM). Prospectively, we recorded 221 cardiovascular events over a mean follow-up time of 6.3±2.3 years.

Results

Cardiovascular event risk was higher in T2DM patients than in those who did not have diabetes (69 vs. 52%, p=0.001). The ceramides Cer(18:1/16:0) and Cer(18:1/24:1) and the respective ratios Cer(18:1/16:0) / Cer(18:1/24:0) and Cer(18:1/24:1) / Cer(18:1/24:0) were significant predictors of cardiovascular events both univariately and after multivariate adjustment including the presence of T2DM (figure). Conversely, T2DM predicted cardiovascular events independently from the investigated ceramides (adjusted HR 1.76 [1.31–2.35], p<0.001).

Conclusion

We conclude that the investigated ceramides and T2DM are mutually independent predictors of cardiovascular events in PAD patients.

New evidence from plasma ceramides links apoE polymorphism to greater risk of coronary artery disease in Finnish adults

apoE, a key regulator of plasma lipids, mediates altered functionalities in lipoprotein metabolism and thus affects the risk of coronary artery disease (CAD). The significance of different apoE polymorphisms remains unclear; although the ε4 allele is clearly associated with increased cholesterol levels (which inform CAD risk), direct studies about apoE polymorphisms on CAD risk and development have yielded controversial results. Furthermore, certain species of ceramides-complex lipids abundant in plasma LDL-are markers of increased risk of myocardial infarction and cardiovascular death. Using a high-throughput MS approach, we quantified 30 molecular plasma ceramide species from a cohort of 2,160 apoE-genotyped (rs7412, rs429358) young adults enrolled in the population-based Cardiovascular Risk in Young Finns Study. We then searched this lipidome data set to identify new indications of pathways influenced by apoE polymorphisms and possibly related to CAD risk. This approach revealed a previously unreported association between apoE polymorphism and a consistently documented high-risk CAD marker, Cer(d18:1/16:0). Compared with the apoE ε3/3 reference group, plasma levels of apoE ε4 were elevated and those of apoE ε2 were lowered in all subjects without evidence of apoE-by-sex interactions. apoE associated with seven ceramides that are connected to atherogenically potent macrophages and/or lipoprotein particles; these associations could indicate a plausible linkage between apoE polymorphism and ceramide metabolism, leading to adverse plasma LDL metabolism and atherogenesis. In conclusion, new evidence from plasma ceramides links apoE polymorphism with an increased risk of CAD and extends our understanding of the role of apoE in health and disease.

Association of Plasma Ceramides With Myocardial Perfusion in Patients With Coronary Artery Disease Undergoing Stress Myocardial Perfusion Scintigraphy

Objective- It is known that specific plasma ceramides are associated with stress-induced reversible myocardial perfusion defects in patients with established or suspected coronary artery disease undergoing myocardial perfusion scintigraphy (MPS). However, it is currently uncertain whether plasma ceramides are also associated with reduced poststress myocardial perfusion in these patients. Approach and Results- We measured 6 previously identified high-risk plasma ceramide species (ceramide [d18:1/16:0], ceramide [d18:1/18:0], ceramide [d18:1/20:0], ceramide [d18:1/22:0], ceramide [d18:1/24:0], and ceramide [d18:1/24:1]) in 167 consecutive patients with established or suspected coronary artery disease undergoing stress MPS for clinical indications. Plasma ceramides were measured by a targeted liquid chromatography-tandem mass spectrometry assay both at baseline and after MPS. Multivariable linear regression analysis was undertaken to examine the associations (standardized B coefficients) between plasma ceramides and the percentage of poststress myocardial perfusion after adjustment for multiple cardiovascular risk factors. Seventy-eight patients had stress-induced myocardial ischemia on MPS (mainly located in the anteroapical wall). Of the 6 measured plasma ceramides, higher levels of basal ceramide (d18:1/18:0; B=-0.182; P=0.019), ceramide (d18:1/20:0; B=-0.224; P=0.004), ceramide (d18:1/22:0; B=-0.163; P=0.035), and ceramide (d18:1/24:1; B=-0.20; P=0.010) were associated with lower poststress anteroapical wall perfusion. Notably, these significant associations persisted even after adjustment for conventional cardiovascular risk factors, previous coronary artery disease, electrocardiographic left bundle branch block, left ventricular ejection fraction and type of stress testing. Similar results were observed for poststress plasma ceramides. Conclusions- Higher circulating levels of specific ceramides, both at baseline and after stress, were independently associated with lower poststress anteroapical wall perfusion in patients with suspected or established coronary artery disease referred for clinically indicated MPS.

The European Collaborative Project on Inflammation and Vascular Wall Remodeling in Atherosclerosis - Intravascular Ultrasound (ATHEROREMO-IVUS) study

AIMS

The European Collaborative Project on Inflammation and Vascular Wall Remodeling in Atherosclerosis - Intravascular Ultrasound (ATHEROREMO-IVUS) study was designed as an exploratory clinical study in order to investigate the associations between genetic variation, coronary atherosclerosis phenotypes, and plaque vulnerability as determined by IVUS.

METHODS AND RESULTS

The ATHEROREMO-IVUS study was a prospective, observational study of 581 patients with stable angina pectoris or acute coronary syndrome (ACS) who were referred for coronary angiography to the Thoraxcenter, Rotterdam, enriched with 265 IBIS-2 participants (total population, n=846). Prior to catheterisation, blood samples were drawn for genetic analyses. During the catheterisation procedure, IVUS was performed in a non-culprit coronary artery. The primary endpoint was the presence of vulnerable plaque as determined by IVUS virtual histology (VH). In addition, we performed a genome-wide association study of plaque morphology. We observed strong signals associated with plaque morphology in several chromosomal regions: twelve SNPs (rs17300022, rs6904106, rs17177818, rs2248165, rs2477539, rs16865681, rs2396058, rs4753663, rs4082252, rs6932, rs12862206, rs6780676) in or near eight different genes (GNA12, NMBR, SFMBT2, CUL3, SESN3, SLC22A25, EFBN2, SEC62) were most significant.

CONCLUSIONS

In conclusion, we found twelve SNPs in or in the proximity of eight genes, which were possibly associated with markers of vulnerable plaque. ClinicalTrials.gov Identifier: NCT01789411.

Whole blood microRNA levels associate with glycemic status and correlate with target mRNAs in pathways important to type 2 diabetes

We analyzed the associations between whole blood microRNA profiles and the indices of glucose metabolism and impaired fasting glucose and examined whether the discovered microRNAs correlate with the expression of their mRNA targets. MicroRNA and gene expression profiling were performed for the Young Finns Study participants (n = 871). Glucose, insulin, and glycated hemoglobin (HbA1c) levels were measured, the insulin resistance index (HOMA2-IR) was calculated, and the glycemic status (normoglycemic [n = 534]/impaired fasting glucose [IFG] [n = 252]/type 2 diabetes [T2D] [n = 24]) determined. Levels of hsa-miR-144-5p, -122-5p, -148a-3p, -589-5p, and hsa-let-7a-5p associated with glycemic status. hsa-miR-144-5p and -148a-3p associated with glucose levels, while hsa-miR-144-5p, -122-5p, -184, and -339-3p associated with insulin levels and HOMA2-IR, and hsa-miR-148a-3p, -15b-3p, -93-3p, -146b-5p, -221-3p, -18a-3p, -642a-5p, and -181-2-3p associated with HbA1c levels. The targets of hsa-miR-146b-5p that correlated with its levels were enriched in inflammatory pathways, and the targets of hsa-miR-221-3p were enriched in insulin signaling and T2D pathways. These pathways showed indications of co-regulation by HbA1c-associated miRNAs. There were significant differences in the microRNA profiles associated with glucose, insulin, or HOMA-IR compared to those associated with HbA1c. The HbA1c-associated miRNAs also correlated with the expression of target mRNAs in pathways important to the development of T2D.

Dedifferentiation of Primary Hepatocytes is Accompanied with Reorganization of Lipid Metabolism Indicated by Altered Molecular Lipid and miRNA Profiles

Aim: Primary human hepatocytes (PHHs) undergo dedifferentiation upon the two-dimensional (2D) culture, which particularly hinders their utility in long-term in vitro studies. Lipids, as a major class of biomolecules, play crucial roles in cellular energy storage, structure, and signaling. Here, for the first time, we mapped the alterations in the lipid profile of the dedifferentiating PHHs and studied the possible role of lipids in the loss of the phenotype of PHHs. Simultaneously, differentially expressed miRNAs associated with changes in the lipids and fatty acids (FAs) of the dedifferentiating PHHs were investigated. Methods: PHHs were cultured in monolayer and their phenotype was monitored morphologically, genetically, and biochemically for five days. The lipid and miRNA profile of the PHHs were analyzed by mass spectrometry and Agilent microarray, respectively. In addition, 24 key genes involved in the metabolism of lipids and FAs were investigated by qPCR. Results: The typical morphology of PHHs was lost from day 3 onward. Additionally, ALB and CYP genes were downregulated in the cultured PHHs. Lipidomics revealed a clear increase in the saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) containing lipids, but a decrease in the polyunsaturated fatty acids (PUFA) containing lipids during the dedifferentiation of PHHs. In line with this, FASN, SCD, ELOVL1, ELOVL3, and ELOVL7 were upregulated but ELOVL2 was downregulated in the dedifferentiated PHHs. Furthermore, differentially expressed miRNAs were identified, and the constantly upregulated miR-27a and miR-21, and downregulated miR-30 may have regulated the synthesis, accumulation and secretion of PHH lipids during the dedifferentiation. Conclusion: Our results showed major alterations in the molecular lipid species profiles, lipid-metabolizing enzyme expression as wells as miRNA profiles of the PHHs during their prolonged culture, which in concert could play important roles in the PHHs’ loss of phenotype. These findings promote the understanding from the dedifferentiation process and could help in developing optimal culture conditions, which better meet the needs of the PHHs and support their original phenotype.