Why do women typically have better cholesterol profiles than men, yet lose this protective advantage after menopause? New molecular evidence points to an X-linked enzyme that specifically governs female cholesterol metabolism through a previously unknown epigenetic pathway. This discovery could reshape how we approach cardiovascular prevention in women across different life stages.
Researchers identified KDM6A, a histone demethylase enzyme located on the X chromosome, as a master regulator of hepatic cholesterol processing in females. When KDM6A levels were reduced in human female liver cells, critical lipoprotein regulation programs became disrupted, while male cells remained unaffected. Female mice lacking hepatic KDM6A developed pro-atherogenic blood lipid profiles and accelerated atherosclerosis under metabolic stress, confirming the sex-specific protective role. The mechanism involves KDM6A partnering with transcription factor HNF4A to activate chromatin and enable CREBH-mediated expression of lipid metabolic genes.
This finding illuminates the molecular architecture behind well-documented sex differences in cardiovascular risk. Women's dual X chromosomes may provide redundant KDM6A expression that helps maintain optimal cholesterol metabolism throughout reproductive years. The research suggests that hormonal changes affecting KDM6A activity could partially explain why postmenopausal women lose their cardiovascular advantage. From a therapeutic perspective, this pathway represents a novel target for sex-specific interventions. However, the work was conducted primarily in cell culture and mouse models, requiring validation in human populations. The discovery nonetheless represents a significant advance in understanding why cardiovascular disease manifests so differently between sexes at the molecular level.
