Associations between high blood pressure and DNA methylation.

Area of Science:

• Epigenetics
• Cardiovascular Disease Epidemiology
• Genomics

Background:

• High blood pressure is a key risk factor for cardiovascular disease (CVD), influenced by environmental and genetic elements.
• Epigenetic mechanisms, such as DNA methylation, may link genetic predispositions, environmental exposures, and CVD.
• South Asians exhibit higher risks of hypertension and CVD than Europeans, but ethnic differences in blood pressure-associated DNA methylation remain unclear.

Purpose of the Study:

• To investigate DNA methylation sites and regions associated with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension.
• To explore potential ethnic differences in DNA methylation associations with blood pressure between South Asian and European men.

Main Methods:

• Conducted an epigenome-wide association study (EWAS) and differentially methylated region (DMR) analysis.
• Analyzed blood DNA methylation data from 364 European and 348 South Asian men (Southall And Brent REvisited cohort) using the Illumina Infinium® HumanMethylation450 BeadChip.
• Performed trans-ancestry and ancestry-specific analyses for SBP, DBP, and hypertension.

Main Results:

• One CpG site associated with DBP in combined analyses; seven CpG sites associated with DBP in European-only analyses.
• No significant associations found between DNA methylation and SBP or hypertension.
• Limited concordance in effect sizes between South Asian and European EWAS for DBP, SBP, and hypertension.
• DMR analysis identified regions related to CVD and its risk factors.

Conclusions:

• Identified specific DNA methylation sites and regions associated with blood pressure.
• Revealed significant ethnic differences in DNA methylation associations with blood pressure.
• Findings suggest potential molecular pathways contributing to the elevated CVD risk in South Asians compared to Europeans.