Subclinical atherosclerosis and accelerated epigenetic age mediated by inflammation: a multi-omics study

Abstract

Aims: Epigenetic age is emerging as a personalized and accurate predictor of biological age. The aim of this article is to assess the association of subclinical atherosclerosis with accelerated epigenetic age and to investigate the underlying mechanisms mediating this association.

Methods and results: Whole blood methylomics, transcriptomics, and plasma proteomics were obtained for 391 participants of the Progression of Early Subclinical Atherosclerosis study. Epigenetic age was calculated from methylomics data for each participant. Its divergence from chronological age is termed epigenetic age acceleration. Subclinical atherosclerosis burden was estimated by multi-territory 2D/3D vascular ultrasound and by coronary artery calcification. In healthy individuals, the presence, extension, and progression of subclinical atherosclerosis were associated with a significant acceleration of the Grim epigenetic age, a predictor of health and lifespan, regardless of traditional cardiovascular risk factors. Individuals with an accelerated Grim epigenetic age were characterized by an increased systemic inflammation and associated with a score of low-grade, chronic inflammation. Mediation analysis using transcriptomics and proteomics data revealed key pro-inflammatory pathways (IL6, Inflammasome, and IL10) and genes (IL1B, OSM, TLR5, and CD14) mediating the association between subclinical atherosclerosis and epigenetic age acceleration.

Conclusion: The presence, extension, and progression of subclinical atherosclerosis in middle-aged asymptomatic individuals are associated with an acceleration in the Grim epigenetic age. Mediation analysis using transcriptomics and proteomics data suggests a key role of systemic inflammation in this association, reinforcing the relevance of interventions on inflammation to prevent cardiovascular disease.

Trial registration: ClinicalTrials.gov NCT01410318.

Keywords: Epigenetic age acceleration; Methylomics; Proteomics; Subclinical atherosclerosis; Systemic inflammation; Transcriptomics.

Structured Graphical Abstract

The accelerated epigenetic age of individuals with subclinical atherosclerosis is mediated by a low-grade, chronic, systemic inflammation driven by key inflammatory cytokines and pathways.

Figure 1

The presence and extension of subclinical atherosclerosis in Progression of Early Subclinical Atherosclerosis participants is associated with epigenetic clocks predictive of time-to-death. (A) Odds ratio of the logistic regression models for the presence of subclinical atherosclerosis based on different imaging techniques: 3DVUS PVB (positive global plaque burden measured by 3DVUS); coronary artery calcium score (positive calcium score measured using computed tomography, Agatson); 2DVUS NT (at least one territory with plaque detected by 2DVUS) and PS (Progression of Early Subclinical Atherosclerosis score focal, intermediate or generalized vs. No disease). (B) Proportional odds-ratio of the ordinal logistic regression for the following categories of each imaging technique: 3DVUS PVB: Tertiles of 3DVUS global plaque volume as previously described; CACS (0, 1–10, 10–100, >100); 2DVUS NT (number of territories with 2DVUS atherosclerotic plaque); PS (Progression of Early Subclinical Atherosclerosis Score: no disease, focal, intermediate, and generalized disease). * P < .05. All models were adjusted by diabetes, gender, smoking, dyslipidemia, obesity, family history of CVD, and hypertension. CACS, coronary artery calcium score; EAA, epigenetic age acceleration; OR, odds ratio; pOR, proportional odds-ratio.

Figure 2

Progression of Early Subclinical Atherosclerosis participants with larger extension of subclinical atherosclerosis have accelerated grim epigenetic age. a–h boxplots (A, C, E, G) and forest plots (B, D, F, H) for the ordinal logistic regression of the extension of subclinical atherosclerosis and Grim epigenetic age acceleration. Subclinical atherosclerosis was assessed using different metrics and imaging techniques: 3DVUS plaque volume (A, B), calcification of coronary arteries by computed tomography (C, D); number of territories with plaques detected by 2DVUS (E, F), and Progression of Early Subclinical Atherosclerosis score (G, H). Models were adjusted by diabetes, gender, smoking, dyslipidemia, obesity, family history of CVD, and hypertension. Jonckheere-Terpstra test for trend <0.001 for all comparisons in panels (A, C, E, G). Forest plots in panels (B, D, F, H) display the proportional Odds Ratio of the ordinal logistic regression model and its 95% Confidence Interval. EAA, epigenetic age acceleration; CACS, coronary artery calcium score; PESA, Progression of Early Subclinical Atherosclerosis.

Figure 3

Subclinical atherosclerosis association with Grim epigenetic age acceleration in the Multi-Ethnic Study of Atherosclerosis study. (A) Distribution of the proportions of participants with coronary artery calcium score <0.5 (0) or > 0.5 (+) across Grim epigenetic age acceleration categories. (B) Distribution of Grim epigenetic age acceleration across different levels of carotid plaque burden measured as previously described. EAA, epigenetic age acceleration; CAC, coronary artery calcium.

Figure 4

Progression of Early Subclinical Atherosclerosis individuals with accelerated grim epigenetic age have a higher predicted risk of having a cardiovascular event in 10 years and an increased cardiovascular age predicted by traditional cardiovascular risk scores. (A) Proportion of individuals with low atherosclerotic cardiovascular disease risk, borderline risk, medium risk, and high risk among individuals with accelerated, normal, or decelerated Grim epigenetic age. Chi² test P < .001. (B) Cardiovascular age derived from the Systematic Coronary Risk Evaluation algorithm calculated for individuals with accelerated, normal, and decelerated Grim epigenetic age (colour coded based on atherosclerotic cardiovascular disease risk score). ANOVA and t-test P-values are displayed. ASCVD, atherosclerotic cardiovascular disease; LR, low risk; BR, borderline risk; MR, medium; HR, high risk.

Figure 5

Transcriptomics analysis identifies inflammatory pathways as mediators between subclinical atherosclerosis and accelerated grim epigenetic age. ChordPlot of the most representative genes from the top 10 most enriched canonical pathways enriched in mediator genes after adjustment by cardiovascular risk factors. Data extracted from Supplementary data online, Table S9. logFC represents changes associated with EAA (online Table S7).