DNA Methylation Signatures of Cardiovascular Health Provide Insights into Diseases

Abstract

Background: The association of overall cardiovascular health (CVH) with changes in DNA methylation (DNAm) has not been well characterized.

Methods: We calculated the American Heart Association's Life's Essential 8 (LE8) score to reflect CVH in five cohorts with diverse ancestry backgrounds. Epigenome-wide association studies (EWAS) for LE8 score were conducted, followed by bioinformatic analyses. DNAm loci significantly associated with LE8 score were used to calculate a CVH DNAm score. We examined the association of the CVH DNAm score with incident CVD, CVD-specific mortality, and all-cause mortality.

Results: We identified 609 CpGs associated with LE8 score at false discovery rate (FDR) < 0.05 in the discovery analysis and at Bonferroni corrected P < 0.05 in the multi-cohort replication stage. Most had low-to-moderate heterogeneity (414 CpGs [68.0%] with I² < 0.2) in replication analysis. Pathway enrichment analyses and phenome-wide association study (PheWAS) search associated these CpGs with inflammatory or autoimmune phenotypes. We observed enrichment for phenotypes in the EWAS catalog, with 29-fold enrichment for stroke (P = 2.4e-15) and 21-fold for ischemic heart disease (P = 7.4e-38). Two-sample Mendelian randomization (MR) analysis showed significant association between 141 CpGs and ten phenotypes (261 CpG-phenotype pairs) at FDR < 0.05. For example, hypomethylation at cg20544516 (MIR33B; SREBF1) associated with lower risk of stroke (P = 8.1e-6). In multivariable prospective analyses, the CVH DNAm score was consistently associated with clinical outcomes across participating cohorts, the reduction in risk of incident CVD, CVD mortality, and all-cause mortality per standard deviation increase in the DNAm score ranged from 19% to 32%, 28% to 40%, and 27% to 45%, respectively.

Conclusions: We identified new DNAm signatures for CVH across diverse cohorts. Our analyses indicate that immune response-related pathways may be the key mechanism underpinning the association between CVH and clinical outcomes.

Figure 1.

Study design flow-chart. EWAS: epigenome-wide association study, PheWAS: phenome-wide association study, DNAm: DNA methylation, MR: Mendelian randomization, FHS: Framingham Heart Study, CARDIA: Coronary Artery Risk Development in Young Adults Study, MESA: Multi-Ethnic Study of Atherosclerosis, SHIP: The Study of Health in Pomerania, SHS: Strong Heart Study, JHS: Jackson Heart Study

Figure 2.

Manhattan plot for LE8 EWAS. Plot was generated using data from combined analysis of all five cohorts (FHS, CARDIA, MESA, SHIP, and SHS). The number of common CpGs in all five cohorts was 397,905 and the number of common CpGs in replication cohorts were 783,289.

Figure 3.

GO term network analysis. Biological process GO terms (level 3) clustered based on shared gene annotations. Nodes were only included if they belonged to a cluster of at least three terms and if they had an FDR < 0.05.

Figure 4:

Hazard ratios for DNAm LE8 score for incident CVD, CVD mortality, and all-cause mortality. Hazard ratios are relative to one standard deviation increase in DNAm LE8 score. Model adjusted for sex, age, estimated leukocyte composition, cohort-specific covariates such as research centers, self-reported race/ethnicity, and education levels.