By Lisa Rapaport / Reuters Health
If you are above the crowd there is a higher risk of developing varicose veins, as a large genetic study shows.
Varicose veins are swollen, twisted veins that are visible just below the surface of the skin, usually in the legs. More than 30 million people in the US have varicose veins. Although the condition is often dismissed only as a cosmetic nuisance, it can cause moderate pain and has been linked to the more serious side effect of deep vein thrombosis or blood clots in the deep veins of the body.
For the current study, researchers analyzed data from nearly 500,000 individuals participating in the UK's long-term biobank study and looked for features associated with varicose veins risk and body size was a strong, independent risk factor.
They followed this with a genome-wide scan of several hundred thousand people, who identified 30 genetic sites, many of which were involved in the development of the skeleton and blood vessels, suggesting that size may be a direct cause of varicose veins.
"We do not yet know why the height is such a strong risk factor for varicose veins," said senior study author Dr. Nicholas Leeper from Stanford University in California.
"It can be a simple matter of plumbing and gravity, with larger individuals experiencing greater pressure in their veins, causing them to expand and expand," Leeper said via email. "On the other hand, the strong genetic studies we have conducted have shown that body size is not only related to disease, but also appears to be the cause of disease – an important distinction, since the genes that regulate human body size play a role in the structure and in the body could play integrity of the veins. "
The analysis used machine learning to search Biobank participants' data for patterns that linked varicose veins with other characteristics, and confirmed that known risk factors – including the elderly, female, overweight, or pregnant – or a history of deep vein thrombosis – were linked stand with varicose veins.
Surgery on the legs, family history, physical inactivity, smoking and hormone therapy are also risk factors for varicose veins, the study confirmed.
However, the connection between height and varicose veins was new and unexpected.
If you compare the highest 25% of people with the shortest, the analysis shows that the highest risk of varicose veins was 74% more risk, according to the results in the blood circulation.
In addition, the researchers studied genetic markers associated with varicose veins in 337,536 people, of which 9,577 had varicose vein disease. The resulting 30 sites in the genome provide researchers with new clues to study the mechanisms involved in the development and risk of a varicose vein, the authors note.
One limitation of the study is that UK biobank participants may not reflect what would happen to populations in other parts of the world.
Yet, it provides one of the most comprehensive insights yet into the environmental and biological factors that could influence the risk of varicose veins, Dr. Quinn Wells from Vanderbilt University Medical Center, Nashville, Tennessee.
"Although the results of this study can not directly affect patient care, understanding these factors is the first step in developing effective interventions for the prevention and treatment of varicose veins," said Wells, who wrote an accompanying editorial, by e-mail.
In general, people can help prevent varicose veins by maintaining a healthy body weight and exercising to improve muscle strength and circulation, Wells advises.