Abstract P106: Epigenetic Age Acceleration and Postprandial Lipemia in the Genetics of Lipid Lowering Drugs and Diet Network Study

Abstract

Background: Calculated ‘epigenetic age,’ a novel biomarker based on DNA methylation levels of 353 CpGs, has been demonstrated to accurately predict chronological age across a broad spectrum of tissues and cell types. Recently epigenetic age acceleration or older epigenetic age in comparison to chronological age has been robustly associated with all-cause mortality independent of chronological age in multiple human cohorts. However, accelerated epigenetic aging has not been associated with lipids levels, including postprandial lipid levels which are linked to prothrombotic and proinflammatory processes that may precipitate aging. In the current study we aimed to evaluate the association between epigenetic age acceleration and lipid levels. Methods: We used the Horvath DNA methylation age calculator to estimate epigenetic age in 988 Caucasian participants from the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) using Illumina Infinium HumanMethylation450 BeadChip array data derived from CD4+ T-cell DNA. GOLDN participants did not take lipid lowering drugs for at least four weeks prior to enrollment and underwent a standardized high fat meal challenge after fasting for at least 8 hours followed by timed blood draws at 3.5 and 6 hours following the meal. Epigenetic age acceleration was calculated as the residual from regressing methylation age on chronological age. We used linear mixed models to examine the association of age acceleration quartiles with fasting and postrandial (3.5 and 6 hour time points) low density lipoprotein (LDL), high density lipoprotein (HDL) and triglyceride (TG) levels after adjusting for age, study site, sex, fasting lipid level (if applicable), deconvolution estimated T-cell type percentages and a random effect of family relationship. Results: The correlation between calculated methylation age and chronological age was 0.91. The difference between methylation age and chronological age (methylation age - chronological age) was on average -5.8 (5.9), -0.5 (4.7), 2.9 (4.3), and 7.8 (5.0) years for the first through fourth quartiles of age acceleration, respectively. After adjustment for covariates neither fasting nor postprandial lipids were associated with age acceleration quartile. Conclusions: Evidence from the current study suggests lipid levels in the fasting and postprandial state are not related to accelerated epigenetic aging, however given the association between epigenetic age acceleration and mortality observed in previous studies the relationship of other metabolic parameters with age acceleration may be worthy of investigation.