Study reports height as a risk factor for the development of varicose veins

by Lucy Turnipseed | 10/18/18 2:45am

Taller members of the population may need to be more vigilant in monitoring the appearance of their veins. A recent study on the environmental and genetic factors that lead to varicose veins has found that height is a risk factor for the condition, which results in swollen, visible veins most commonly seen in the legs and feet. The study also confirmed the correlation between deep vein thrombosis and a higher likelihood for developing varicose veins. Alyssa Flores Med’20 was an author of the study.

“We got a lot of positive feedback and I think that speaks to the need [the study] addressed,” Flores said.

The study, the largest one ever done on varicose veins, originated at the Stanford University School of Medicine with a team headed by Nicholas Leeper, a surgery and cardiovascular medicine professor and head of the Leeper Lab at Stanford University.

According to Leeper, the study’s findings bring scientists one step closer to developing early-stage treatments and medical therapies for the disease.

Flores, a Howard Hughes Medical Institute Medical Research Fellow, spent a year at Stanford launching her research career in the vascular surgery division.

Leeper’s lab chose to study varicose veins because the condition affects many Americans but is relatively understudied, according to Flores, who added that the condition has only late-stage treatments like surgery to move the veins or compression stockings that assist with circulation.

“We thought it was an important problem because varicose veins are so prevalent, and it’s a condition which is actually highly morbid,” Leeper said.

He added that the condition impacts people’s quality of life and “can have some pretty important side effects.”

“If we can figure out what the risk factors are, then it’s kind of like cardiovascular disease — we can try to do risk factor modification, ask what we can do to minimize the risk factors,” said Stanford University vascular medicine professor Eri Fukaya, who worked on the study with Leeper’s team. “If we don’t know the mechanism … we can’t devise an early treatment plan.”

Leeper added that scientists know very little about varicose veins and there are no medical therapies for it. He emphasized the need to fill the “knowledge gap” surrounding the “prevalent and important condition.”

Using machine learning, the team searched the U.K. Biobank, a database of over half a million individuals dedicated to collecting genetic and lifestyle information over time.

“It’s a new way of doing science where you don’t go in with a hypothesis, so you’re not really restricted to the ideas you bring to the table — rather, you’re able to come up with novel findings using a machine learning algorithm,” Flores said.

The U.K. Biobank database also allowed the team to conduct a genome-wide association study, identifying traits present in people with varicose veins and comparing them to healthy individuals to identify the risk factors for the condition.

“It’s very powerful studying population-level science,” Flores said.

With 3,000 variables available for cross-referencing, some common risk factors like pregnancy and age were confirmed in addition to the emergence of the new findings about height as a risk factor.

“We went in agnostically to see if in this cohort of people [with varicose veins] we could finally find some sort of genetic [inheritance] for these veins,” Fukaya said.

Leeper added that the genes and pathways causing people to be taller also affect the vascular biology putting individuals at risk for varicose veins.

Flores later presented the findings of the varicose veins study at Vascular Discovery, an American Heart Association function, and received the 2018 Peripheral Vascular Disease Early Career Investigator Award for her work.

“It was an honor for me this early on in my training to receive the award,” Flores said. “I felt that moment for me was when I could really envision [studying cardiovascular disease] being what I devote my life’s work to.”

Fukaya said that involvement in projects like this one will sharpen Flores’ skills for her future medical career.

“[Flores is] a whiz at figuring things out,” she said.

Geisel School of Medicine surgery professor and Dartmouth-Hitchcock Medical Center attending cardiac surgeon Alexander Iribarne, who has worked with Flores, said he believes her year off for research will “sharpen her perspective” to her medical career.

“[Flores is] a great example of someone who really took the initiative to seek out mentorship and has really taken advantage of all the opportunities for students interested in cardiovascular research,” Iribarne said.