Objective: To explore the DNA methylation sites correlated with blood pressure (systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure) in adult twin population.
Methods: A total of 476 twins from the Chinese National Twin Registry were selected as the research population. Questionnaires were used to collect demographic characteristics, lifestyle, disease status and other information, and blood pressure, height, weight and other anthropometric indicators were measured. The genome-wide DNA methylation of whole blood samples was detected by using Infinium HumanMethylation450 BeadChip. The DNA methylation sites correlated with blood pressure were analyzed by constructing mixed effect model with adjusting potential confounding factors, and the significant level was false discovery rate <0.05.
Results: After data quality control, 465 twins (122 pairs of monozygotic twins, 104 pairs of dizygotic twins, 13 individuals from 13 pairs of twins) aged (44.8±13.2) years were finally enrolled. There were more males and more monozygotic twins, and the current smokers and current regular drinkers both accounted for more than 30%. No significant CpG site was found after multiple testing in the correlation study between genome-wide DNA methylation and blood pressure by using the collected twins. However, the cg07761116 located on chromosome 10 had low P value in the correlation analysis of 3 blood pressure indices (systolic blood pressure, diastolic blood pressure, mean arterial pressure), suggesting that this site might be correlated with blood pressure. The other 7 sites had low P value in the correlation analysis of the two blood pressure indices, respectively, which pointed to genes involved in neurological development, protein homeostasis, inflammatory reaction and other pathways.
Conclusion: There is no sufficient evidence to support any DNA methylation site correlated with blood pressure, which may be caused by insufficient sample size and other reasons. This study could provide a reference for subsequent similar twin studies, and subsequent studies can focus on the cg07761116 located on chromosome 10 and other sites with low P values.