There are plenty of perks to being tall: Reaching the top shelf, changing light bulbs with ease, seeing over everyone’s head at a concert.
But doctors have just found a major drawback in research published Monday in the journal Circulation. The taller a person is, the more likely he or she is to suffer from varicose veins, according to researchers at Stanford University’s School of Medicine.
Their research showed a causal link, rather than just a correlation, between height and varicose veins — suggesting the genes that make people tall are “an underlying mechanism leading to varicose veins,” Erik Ingelsson, a professor of cardiovascular medicine and an author of the study, said in a statement.
The authors described the new research as “the largest genetic study ever performed for varicose vein disease.”
Varicose veins are knotty, swollen and often bruise-colored protruding veins generally found in the legs. Though varicose veins are remarkably common — some 30 million in the United States alone have them — they’re also remarkably under-studied, the Stanford researchers said.
“The condition is incredibly prevalent but shockingly little is known about the biology. There are no medical therapies that can prevent it or reverse it once it’s there,” medical student Alyssa Flores, another author of the study, said in a statement.
Available treatments include vein stripping and laser treatment — but the study said that there are currently “no approved medical therapies.”
“We’re hoping that with this new information, we can create new therapies, as our study highlights several genes that may represent new translational targets,” Flores said.
Varicose veins aren’t just a cosmetic concern, either. They can be painful and are associated with deep vein thrombosis, in which deep veins develop a blood clot. Varicose veins can also lead to skin ulcers, according to the National Institutes of Health.
To make the connection between height and varicose veins (which Flores said she was “very surprised” to discover) the Stanford researchers used UK Biobank data that includes more than 400,000 people’s genomic data, researchers said.
The researchers created a machine-learning algorithm to hunt for associations between possible predictors and the vein condition, and then ran it on the data.
“You go in without a hypothesis about a specific biological mechanism and scan for something new. You could say that you turn the machine loose on it,” Ingelsson said of the algorithm, which is a type of artificial intelligence. “In this case, we included 2,716 predictors of varicose veins in this machine-learning algorithm. Then we let the algorithms find the strongest predictors of varicose veins.”
The research also demonstrated that women, older people, those who are overweight, those who are pregnant and those with a history of deep vein thrombosis are more likely to develop varicose veins.
Researchers said they’re still trying to figure out what it is about height that increases varicose vein risk.
“We don’t understand it,” said Nicholas Leeper, another Stanford professor and study author, according to CNN. “Perhaps taller people are affected by gravity, or there could be something in the vessel wall itself. What is happening, we just don’t know.”