Obesity and Bariatric Surgery Drive Epigenetic Variation of Spermatozoa in Humans.
Level 4 - case-series / case-control
Cross-sectional comparison and uncontrolled prospective before-and-after cohort study
PubMed 26669700 · doi:10.1016/j.cmet.2015.11.004
What was done
Epigenomic profiling (histone positioning, small non-coding RNA expression, and DNA methylation) was performed on spermatozoa from lean and obese men. In a separate cohort of men with morbid obesity, changes in sperm DNA methylation patterns were evaluated before and after bariatric surgery-induced weight loss.
What was found
Histone positioning was similar between lean and obese men, but small non-coding RNA expression and DNA methylation patterns differed markedly. Following bariatric surgery, significant remodeling of sperm DNA methylation was observed, notably at genomic regions implicated in the central control of appetite. The abstract reports no numerical values, effect sizes, or p-values.
Why it matters
This study provides evidence that human sperm epigenetic marks are dynamically altered by weight loss, pointing to a potential mechanism for nongenetic paternal transmission of metabolic traits.
Limits
Sample sizes, participant characteristics, and specific effect sizes are not reported in the abstract. The study is observational without a non-surgical weight-loss control group mentioned, and functional effects on offspring phenotype or clinical outcomes were not assessed.
Cited by
- supports Bariatric surgery in morbidly obese men alters epigenetic methylation patterns in sperm DNA across hundreds of genes toward profiles seen in lean men.