Association Between BMI and DNA Methylation in Blood or Normal Adult Breast Tissue: A Systematic Review.

Background/aim: Several studies have investigated the influence of obesity on DNA methylation (DNAm) to find biomarkers associated with the detection of chronic diseases, including breast cancer. The aim of the study was to systematically review studies examining the association of body mass index (BMI) and DNAm in blood or normal breast tissue.

Materials And Methods: Three scientific literature databases (PubMed, Embase and Web of Science) were screened until May 2018.

Results: Twenty-four studies were included along with ours in which we investigated this relation in the normal breast tissue of 40 breast cancer patients.

Conclusion: BMI-associated CpG sites were highly variable with few identified in less than half of the studies. Nevertheless, a few genes potentially associated with BMI were highlighted in blood (CPT1A, ABCG1, SREBF1 and LGALS3BP) and in normal breast tissue (PTPRN2 and ABLIM2). The variability of the results could be explained by the tissue and cell-specificity of methylation and differences in methodology.