AbstractBackgroundAccumulating evidence links paternal adiposity in the peri-conceptional period to offspring health outcomes. DNA methylation has been proposed as a mediating mechanism, but very few studies have explored this possibility in humans.Methods and findingsIn the Pregnancy And Childhood Epigenetics (PACE) consortium, we conducted a meta-analysis of co-ordinated epigenome-wide association studies (EWAS) of paternal prenatal Body Mass Index (BMI) (with and without adjustment for maternal BMI) in relation to DNA methylation in offspring blood at birth (13 datasets; total n= 4,894) and in childhood (six datasets; total n = 1,982). We found little evidence of association at either time point: for all CpGs, the False Discovery Rate-adjusted P-values were >0.05. In sex-stratified analyses, we found just four CpGs where there was robust evidence of association in female offspring. To compare our findings to those of other studies, we conducted a systematic review, which identified seven studies, including five candidate gene studies showing associations between paternal BMI/obesity and offspring or sperm DNA methylation at imprinted regions. However, in our own study, we found very little evidence of enrichment for imprinted genes.ConclusionOur findings do not support the hypothesis that paternal BMI around the time of pregnancy is associated with offspring blood DNA methylation, even at imprinted regions.Author SummaryPrevious small, mostly candidate gene studies have shown associations between paternal pre-pregnancy BMI and offspring blood DNA methylation. However, in our large meta-analysis of co-ordinated EWAS results from a total of 19 datasets across two timepoints, we found little evidence to support these findings, even at imprinted regions. This does not rule out the possibility of a paternal epigenetic effect in different tissues, at regions not covered by the 450k array, via different mechanisms, or in populations with greater extremes of paternal BMI. More research is warranted to help understand the size and nature of contributions of paternal adiposity to offspring epigenetics and health outcomes.
Candidate gene studies in gallbladder cancer: A systematic review and meta-analysis
