What do XX chromosomes do

XX chromosomes increase heart risk in women

X chromosomes turn women into women - but they have an impact on heart health, as researchers have now found

Image source: Unsplash / Joshua Ness

The XX factor

The presence of two X chromosomes increases the amount of fat circulating in the blood, according to a study by the University of Kentucky. The consequences are narrowing of the arteries and ultimately a higher risk of a heart attack or coronary artery disease.

Coronary artery disease is the leading cause of death in women. However, they become ill an average of ten years later than men. The delay has long been attributed to the protective effects of sex hormones. Indeed, there is plenty of evidence that hormones like estrogen and progesterone protect the heart. However, little data has been available so far on the influence of the X chromosome on this organ. Therefore, the team led by research director Lisa Cassis investigated the effects of chromosomes in mice. Most recently, it was possible to direct the focus to the XX chromosomes. This was made possible by removing hormones.

The scientists have now published their results in the journal "Nature Communications".

According to first author Yasir Al-Siraj, excessively high levels of lipids circulating in the blood lead to an accumulation in and on the arterial walls. These deposits harden and narrow the arteries. This affects the blood supply to important organs. The team studied fats that are ingested through food and produced in the liver. The combination of XX chromosomes was found to promote the effective use of fat.

According to Cassis, women need these fat reserves for pregnancy and breastfeeding. It only becomes problematic when menopause is reached and the protective effect of the hormones ceases to exist. The researchers are currently looking for genetic changes in the liver and intestines. The aim is to find new starting points for the development of new drugs. If it is possible to find genes in atherosclerosis that influence the disease, the effect of existing drugs can be tested and the development of new active ingredients can begin.

Source: University of Kentucky / press release