DNA methylation (DNAm) clocks are important biomarkers of cellular aging and are associated with a variety of age-related chronic diseases and all-cause mortality. Examining the relationship between education and lifestyle risk factors for age-related diseases and multiple DNAm clocks can increase the understanding of how risk factors contribute to aging at the cellular level. This study explored the association between education or lifestyle risk factors for age-related diseases and the acceleration of four DNAm clocks, including intrinsic (IEAA) and extrinsic epigenetic age acceleration (EEAA), PhenoAge acceleration (PhenoAA), and GrimAge acceleration (GrimAA) in the African American participants of the Genetic Epidemiology Network of Arteriopathy. We performed both cross-sectional and longitudinal analyses. In cross-sectional analyses, gender, education, BMI, smoking, and alcohol consumption were all independently associated with GrimAA, whereas only some of them were associated with other clocks. The effect of smoking and education on GrimAA varied by gender. Longitudinal analyses suggest that age and BMI continued to increase GrimAA, and that age and current smoking continued to increase PhenoAA after controlling DNAm clocks at baseline. In conclusion, education and common lifestyle risk factors were associated with multiple DNAm clocks. However, the association with each risk factor varied by clock, which suggests that different clocks may capture adverse effects from different environmental stimuli.

Background: Epigenetic aging measures or clocks are DNA methylation‐based indicators of biological aging, linked to health outcomes and disease risk. Physical activity and exercise may influence epigenetic aging, suggesting a pathway through which it promotes healthier aging and reduces chronic disease burden. In this study, we assessed the association between self‐reported moderate‐to‐vigorous physical activity and epigenetic age acceleration (EAA) in participants of the Health and Retirement Study, followed biennially for 12 years from 2004 to 2016.Methods: Leukocyte DNA methylation was measured from venous blood samples collected in 2016 and second‐generation epigenetic clocks (GrimAge, PhenoAge and DunedinPACE) were used to assess EAA. Physical activity was assessed at each wave, with participants reporting vigorous activity at least once per week or moderate activity more than once per week or more categorized as ‘physically active’. We used weighted linear regression models for cross‐sectional analysis in 2016. Additionally, we used a structured life‐course modelling approach (SLCMA) to assess how the timing of physical activity is associated with EAA, testing both wave‐specific physical activity measures and an accumulation measure indicative of sustained physical activity over the follow‐up period.Results: In 2016, 58% of the participants were classified as physically active. In cross‐sectional analysis, physically active participants had lower EAA than inactive participants: −1.26 (95% confidence interval (CI): −1.59, −0.93) years for GrimAge acceleration, −1.70 (95% CI: −2.26, −1.15) for PhenoAge acceleration and −0.05 (95% CI: −0.06, −0.04) years per chronological year for DunedinPACE, adjusted for age, gender, race/ethnicity, education, total wealth and current smoking status. The associations attenuated slightly but remained significant after further adjusting for body mass index, mobility limitations and chronic disease diagnosis. We found evidence of effect modification in the association between physical activity and EAA by social factors, with stronger associations in males compared to females for DunedinPACE (P_interaction = 0.04) and a positive association between physical activity and increased EAA among Hispanics compared to non‐Hispanic Whites for GrimAge (P_interaction = 0.009). Our longitudinal analysis using SLCMA identified both accumulation and most recent physical activity in 2016 as the strongest predictors of EAA.Conclusions: Our findings highlight physical activity as a robust factor associated with slower epigenetic aging, with both accumulation and concurrent physical activity as the strongest predictors. These results underscore the role of physical activity in promoting healthier biological aging, suggesting its potential as a target for interventions aimed at mitigating age‐related health decline.

Background: Hypertension is a major modifiable risk factor for arteriosclerosis that can lead to target organ damage (TOD) of heart, kidneys, and peripheral arteries. A recent epigenome-wide association study for blood pressure (BP) identified 13 CpG sites, but it is not known whether DNA methylation at these sites is also associated with TOD. Methods: In 1218 African Americans from the Genetic Epidemiology Network of Arteriopathy (GENOA) study, a cohort of hypertensive sibships, we evaluated the associations between methylation at these 13 CpG sites measured in peripheral blood leukocytes and five TOD traits assessed approximately 5 years later. Results: Ten significant associations were found after adjustment for age, sex, blood cell counts, time difference between CpG and TOD measurement, and 10 genetic principal components (FDR q < 0.1): two with estimated glomerular filtration rate (eGFR, cg06690548, cg10601624), six with urinary albumin-to-creatinine ratio (UACR, cg16246545, cg14476101, cg19693031, cg06690548, cg00574958, cg22304262), and two with left ventricular mass indexed to height (LVMI, cg19693031, cg00574958). All associations with eGFR and four associations with UACR remained significant after further adjustment for body mass index (BMI), smoking status, and diabetes. We also found significant interactions between cg06690548 and BMI on UACR, and between 3 CpG sites (cg19693031, cg14476101, and cg06690548) and diabetes on UACR (FDR q < 0.1). Mediation analysis showed that 4.7% to 38.1% of the relationship between two CpG sites (cg19693031 and cg00574958) and two TOD measures (UACR and LVMI) was mediated by blood pressure (Bonferroni-corrected P < 0.05). Mendelian randomization analysis suggests that methylation at two sites (cg16246545 and cg14476101) in PHGDH may causally influence UACR. Conclusions: In conclusion, we found compelling evidence for associations between arteriosclerotic traits of kidney and heart and previously identified blood pressure-associated DNA methylation sites. This study may lend insight into the role of DNA methylation in pathological mechanisms underlying target organ damage from hypertension.

Cardiovascular disease (CVD) is one of the leading causes of morbidity and mortality worldwide, yet the underlying molecular mechanisms remain less understood. Chronic low-grade inflammation is a complex immune response contributing to the pathophysiology of cardiovascular disease. This response is signaled in part by interleukin-6 (IL-6), a pleiotropic, pro-inflammatory cytokine. Phenotypic variance in circulating IL-6 level may be explained in part by DNA methylation which is increasingly being associated with cardiovascular effects. In this study we evaluated methylated DNA (CpG sites) associated with blood IL-6 levels across ∼4,400 ancestrally diverse individuals (81 % self-reported White; 9 % Black or African American, 8 % Hispanic or Latino/a, and 2 % Chinese American). We identified 178 CpG sites associated with IL-6 (p<0.05/∼395,000). Among the sites, cg04437762 is located within the transcription unit of IL6R, a current therapeutic target for inflammatory disease, and cg26692003 and cg00464927 were significant for IL6 and IL6ST trans-CpG-gene transcripts. Functional gene expression downstream of methylation identified cellular response to IL-6 and B-cell regulation and activation pathways. Four genes were linked with both a genetic component of cardiovascular disease and an IL-6 associated CpG site. Three CpG sites identified through Mendelian randomization analyses supported inference of a causal effect on IL-6 levels, including the LYN gene that regulates immune cell signaling and has been previously associated with atherosclerosis. Overall, we identified several novel IL-6-CpG sites and downstream pathways affected by methylation. Follow-up functional studies including the regulation of IL-6 would complement current knowledge of CVD pathophysiology and potential therapeutic targets.

The epigenome likely interacts with traditional and genetic risk factors to influence blood pressure. We evaluated whether 13 previously reported DNA methylation sites (CpGs) are associated with systolic (SBP) or diastolic (DBP) blood pressure, both individually and aggregated into methylation risk scores (MRS), in 3070 participants (including 437 African ancestry (AA) and 2021 European ancestry (EA), mean age = 70.5 years) from the Health and Retirement Study. Nine CpGs were at least nominally associated with SBP and/or DBP after adjusting for traditional hypertension risk factors (p < 0.05). MRS_SBP was positively associated with SBP in the full sample (β = 1.7 mmHg per 1 standard deviation in MRS_SBP; p = 2.7 × 10⁻⁵) and in EA (β = 1.6; p = 0.001), and MRS_DBP with DBP in the full sample (β = 1.1; p = 1.8 × 10⁻⁶), EA (β = 1.1; p = 7.2 × 10⁻⁵), and AA (β = 1.4; p = 0.03). The MRS and BP-genetic risk scores were independently associated with blood pressure in EA. The effects of both MRSs were weaker with increased age (p_interaction < 0.01), and the effect of MRS_DBP was higher among individuals with at least some college education (p_interaction = 0.02). In AA, increasing MRS_SBP was associated with higher SBP in females only (p_interaction = 0.01). Our work shows that MRS is a potential biomarker of blood pressure that may be modified by traditional hypertension risk factors.

To better characterize the potential biological mechanisms underlying insulin resistance (IR) and dementia, we derive cross-population and population specific polygenic scores [PSs] for fasting insulin and IR-related partitioned PSs [pPSs]. We conduct a cross-sectional study of the associations of these genetic scores with neurological outcomes in >17k participants (36% men, mean age 55 yrs) from the Trans-Omics for Precision Medicine (TOPMed) program (50% Non-Hispanic White, 23% Black/African American, 21% Hispanic/Latino American, and 4% Asian American). We report significant negative associations (P < 0.002) of the cross-population (P = 1.3 × 10^-5) and European (P_EA = 3.0 × 10^-8) fasting insulin PSs with total cranial volume, and of a metabolic syndrome European PS with general cognitive function (B_EA = -0.13, P_EA = 0.0002) and lateral ventricular volume (B_EA = 0.09, P_EA = 0.002). We identify suggestive negative associations (P < 0.007) of metabolic syndrome and obesity pPSs with general cognitive function, and of lipodystrophy pPSs with total cranial volume. A higher genetic predisposition to IR is associated with lower brain size, and a genetic predisposition to specific IR-related type 2 diabetes subtypes, such as metabolic syndrome and mechanisms of IR mediated through obesity and lipodystrophy, is potentially involved in cognitive decline.