As men age, some of the Y chromosomes disappear, and research results have shown that this change can increase the risk of cardiovascular disease. The loss of sex chromosomes as they age weakens male characteristics and increases the risk of disease.
Lars Forsberg, a professor in immunology and genetics at Uppsala University in Sweden, noted on the 13th, "We confirmed that the disappearance of the Y chromosome in immune cells leads to more occurrences of atherosclerosis, which narrows blood vessels."
Atherosclerosis is a condition in which cholesterol accumulates in the walls of blood vessels, narrowing them, and is considered a major cause of heart disease. The findings of this study were published on the preprint site for medical papers, medRxiv.
A person's gender is determined by sex chromosomes. Women have two X chromosomes, while men have one X and one Y chromosome. The Y chromosome determines male gender and is responsible for reproductive functions such as sperm formation.
Professor Forsberg's research team examined the vascular conditions of 30,150 men and women aged 50 to 64. Among them, about 12,400 men were analyzed by dividing them into three groups based on the degree of Y chromosome loss, comparing the rates of vascular stenosis with female participants as well.
As a result, 75% of the male group with the most significant Y chromosome loss exhibited vascular stenosis. In contrast, the group with less than 10% loss showed about 60% with vascular stenosis, while the group with no loss had 55%. Women had a vascular stenosis rate of 30%.
The loss of Y chromosomes in men primarily occurs in immune cells, including white blood cells. Some Y chromosomes disappear during the rapid division process of stem cells that create white blood cells, and as they age, these cells accumulate in the body. This phenomenon is observed in about 40% of men aged 70.
This issue began to gain attention after Professor Forsberg's team published their findings in 2014. That study confirmed that elderly men with a greater loss of Y chromosomes in their blood tend to die an average of 5 years and 6 months earlier.
Subsequently, Kenneth Walsh, a professor at the University of Virginia, discovered the correlation between Y chromosome loss and heart disease. Professor Walsh said, "Many men lose their lives due to the loss of Y chromosomes," adding that "a significant reason why men live 6 years shorter than women is due to the instability of sex chromosomes."
The findings of this study also align with research by Thimoteus Speer, a professor at Goethe University in Frankfurt, Germany. Professor Speer's team tracked men who underwent angiography for suspected cardiovascular disease for 10 years and found that when more than 17% of white blood cells had lost the Y chromosome, the risk of dying from a myocardial infarction was more than doubled compared to other men.
Professor Speer stated, "The fact that atherosclerosis ultimately leads to myocardial infarction is consistent with Professor Forsberg's research," and projected that "understanding the mechanism better could enable us to select patients who would benefit significantly from certain treatments through blood tests to check for Y chromosome loss."
However, Professor Walsh noted, "Neither study can definitively state that Y chromosome loss is a direct cause." This indicates that further research is needed. Professor Forsberg also commented, "The loss of Y chromosomes cannot explain all the gender differences in vascular stenosis, and there are other factors involved."
References
medRxiv(2025), DOI: https://doi.org/10.1101/2025.07.10.25331326