The y chromosome is partially lost in the blood cells of older men. If the sex chromosome has disappeared in a particularly large number of blood cells, the men have an increased risk of developing cardiovascular disease and dying from a heart attack, a study now shows. In the future, a blood test could determine the extent of the Y chromosome loss and thus the individual risk. This could better treat those affected.
When men age, the Y chromosome is lost in part of their blood cells, especially in the rapidly dividing white blood cells. This mosaic -like loss of the male sex chromosome (Loy) occurs in more than 20 percent of all men over 60 years and can intensify over time. The change remains unnoticed for a long time, but can influence the functions of the affected blood cells. As a result, men with increasing age have an increased risk of Alzheimer’s, cancer and cardiovascular diseases, as previously stated. In addition to risk factors such as high blood pressure, diabetes and obesity, there may be another genetic risk component for cardiovascular diseases in men.
Loss of Y chromosome increases heart attack risk
A team led by Michael Weyrich from the University Medical Center at the Goethe University in Frankfurt has now examined how strong this connection is. For this purpose, the doctors analyzed blood samples from 1698 men and 739 women from a long -term study whose heart was examined between 1997 and 2000 by cardiac catheter. They searched for changes in the blood plasma and on the DNA of the blood cells.
The evaluation showed that around ten percent of the men examined suffered from a pronounced y-chromosome loss-they had more than 17 percent of the blood cells. “In older patients, in smokers and in patients with heart attack, the loss of the Y chromosome was higher,” reports the team. As suspected, these men had an overall higher risk of cardiovascular diseases. They also had a 50 percent higher probability of dying from the consequences of a heart attack. Men with only minor y-chromosome loss, on the other hand, had a risk of death similar to women.
Weyrich and his colleagues also examined what is behind the negative effect of the Y chromosome loss. According to this, blood cells without a Y chromosome freely release messenger substances that promote inflammation, tissue changes and scar formation in heart tissue, as the team found in laboratory experiments with cell cultures. Various proteins were among the messenger substances, such as growth factors. In addition, 37 genes were changed in the blood cells without Y chromosome and therefore more or less strongly active than in normal blood cells. These gene changes also contributed to tissue hardening in the cardiovascular system.
Blut test could betray individual risk
“Our results show that changes in chromosome that occur with age may play a greater role in heart health than we have thought so far,” says senior author Andreas Zeiher from the University Medical Center Frankfurt. In the future, the findings could help to examine and treat men individually. Risk patients could then be recognized at an early stage via a blood test where you are looking for certain biomarkers. “In the long term, the measurement of the Y chromosome loss could help to identify men with a particularly high risk at an early stage and to treat them in a targeted manner,” said Zeiher.
Source: Michael Weyrich (Goethe University Frankfurt) et al.; European Heart Journal, DOI: 10.1093/Eurheartj/ehaf035