Varicose veins affect 30 million people in the United States, and the many of those people happen to be tall, according to a new report.
Researchers from Stanford University School of Medicine recently conducted a study, published in the Circulation journal, to explore the link between height and varicose veins, which are swollen, twisted veins that can be seen just under the surface of the skin. The condition, usually in the legs, can cause moderate pain and can lead to more serious side effects like blood clots.
For the assessment, the researchers examined the UK Biobank, a genetic repository that includes data on more than 500,000 people aged 40 to 69. They then identified 30 genetic regions associated with the condition and later used an artificial intelligence machine to look for other unknown risk factors.
“These methods represent new ways of thinking about research,” coauthor Erik Ingelsson explained in a statement. “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. 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 machine model confirmed already known factors, such as being older, female, overweight or pregnant or having a history of deep vein thrombosis, which occurs when a blood clot forms in one or more of the deep veins.
They also found an “unexpected” correlation between the condition and height, the findings revealed.
“We were very surprised to find that height came up from our machine-learning analyses,” coauthor Alyssa Flores said.
Upon further investigation using Mendelian randomization analyses, a statistical technique to determine causal effects, they discovered height may not be just a factor but also a cause.
“Our results strongly suggest height is a cause, not just a correlated factor, but an underlying mechanism leading to varicose veins,” Ingelsson said.
While the scientists do not yet understand why taller people may have a heighten risk for varicose veins, the team said they believe they have “a much better understanding of the biology that is altered in people at risk for the disease.”