Association of Methylation Signals With Incident Coronary Heart Disease in an Epigenome-Wide Assessment of Circulating Tumor Necrosis Factor α

IMPORTANCE Tumor necrosis factor alpha (TNF-alpha) is a proinflammatory cytokine with manifold consequences for mammalian pathophysiology, including cardiovascular disease. A deeper understanding of TNF-alpha biology may enhance treatment precision. OBJECTIVE To conduct an epigenome-wide analysis of blood-derived DNA methylation and TNF-alpha levels and to assess the clinical relevance of findings. DESIGN, SETTING, AND PARTICIPANTS This meta-analysis assessed epigenome-wide associations in circulating TNF-alpha concentrations from 5 cohort studies and 1 interventional trial, with replication in 3 additional cohort studies. Follow-up analyses investigated associations of identified methylation loci with gene expression and incident coronary heart disease; this meta-analysis included 11461 participants who experienced 1895 coronary events. EXPOSURES Circulating TNF-alpha concentration. MAIN OUTCOMES AND MEASURES DNA methylation at approximately 450 000 loci, neighboring DNA sequence variation, gene expression, and incident coronary heart disease. RESULTS The discovery cohort included 4794 participants, and the replication study included 816 participants (overall mean [SD] age, 60.7 [8.5] years). In the discovery stage, circulating TNF-alpha levels were associated with methylation of 7 cytosine-phosphate-guanine (CpG) sites, 3 of which were located in or near DTX3L-PARP9 at cg00959259 (beta[SE] = -0.01 [0.003]; P = 7.36 x 10(-8)), cg08122652 (beta[SE] = -0.008 [0.002]; P = 2.24 x 10 -7 ), and cg22930808(beta[SE] = -0.01 [0.002]; P = 6.92 x 10(-8)); NLRC5 at cg16411857 (beta[SE] = -0.01 [0.002]; P = 2.14 x 10(-13)) and cg07839457 (beta[SE] = -0.02 [0.003]; P = 631 x 10(-10)); or ABO, at cg13683939 (beta[SE] = 0.04 [0.008]; P = 1.42 x 10(-7)) and cg24267699 (beta[SE] = -0.009 [0.002]; P = 1.67 x 10(-7)), after accounting for multiple testing. Of these, negative associations between TNF-alpha concentration and methylation of 2 loci in NLRC5 and 1 in DTX3L-14 PARP9 were replicated. Replicated TNF-alpha-linked CpG sites were associated with 9% to 19% decreased risk of incident coronary heart disease per 10% higher methylation per CpG site (cg16411857: hazard ratio [HR], 0.86; 95% Cl. 0.78-1.95; P = .003; cg07839457: HR, 0.89; 95% CI, 0.80-0.94; P = 3.1 x 10(-5); cg00959259: HR, 0.91; 95% CI, 0.84-0.97; P = .002; cg08122652: HR, 0.81; 95% CI, 0.74-0.89; P = 2.0 x 10(-5)). CONCLUSIONS AND RELEVANCE We identified and replicated novel epigenetic correlates of circulating TNF-alpha concentration in blood samples and linked these loci to coronary heart disease risk, opening opportunities for validation and therapeutic applications.