Could Short People Have an Advantage When It Comes to A-Fib?

TUESDAY, Nov. 19, 2019 (HealthDay News) -- Tall folks might be able to reach that high top shelf, but there's a price -- they may be more likely to develop a potentially dangerous abnormal heart rhythm than shorter folks.

New research finds that a person's risk of atrial fibrillation (a-fib) increases by about 3% for every inch over the average height of 5-foot-7.

Further, it appears that certain genes linked to height also are associated with a-fib, said lead researcher Dr. Michael Levin, a cardiology fellow at the University of Pennsylvania Perelman School of Medicine.

Atrial fibrillation is a quivering or irregular heartbeat that increases a person's risk of stroke fivefold. It also raises risk of blood clots, heart failure and other heart-related diseases, the American Heart Association says.

Knowing that tall folks are at increased risk of a-fib could help prevent deaths and disease related to the heart condition, Levin said.

"While we can't change your height, we may be able to modify other risk factors for a-fib in taller individuals and be more aggressive about controlling blood pressure or diabetes or cholesterol," Levin said.

For this study, Levin and his colleagues analyzed genetic data from two international databases.

They looked specifically at genetic variants associated with height in one group of more than 700,000 people, and then identified mutations associated with a-fib in another group of more than 500,000 people.

Statistical analysis revealed that genetic variants linked with height were also strongly associated with a-fib, the researchers found.

Taking it a step further, they then analyzed medical data on nearly 7,000 individuals enrolled in a biobank at the University of Pennsylvania.

They found that height -- and the genetic variants associated with height -- are both strongly associated with an increased risk of a-fib.

However, they're still at a loss for an explanation why, Levin said, and the study did not prove cause and effect.

One theory has held that tall people have larger hearts, and the size of the heart might increase a-fib risk, he said.

"We were able to adjust for that, and it doesn't seem to be related to heart size," Levin said.

Even without an easy explanation, the identification of genes associated with both height and a-fib opens up new doors for future research, said Dr. Michael Valentine, who reviewed the findings. He is immediate past president of the American College of Cardiology and a specialist in cardiac rhythm.

"I thought it was fascinating when they separated all other genetic factors, that height turned out to be a positive factor in the development of atrial fib," said Valentine, a senior cardiologist at the Stroobants Cardiovascular Center of Centra Health in Lynchburg, Va.

"With the epidemic of a-fib we see in the world and an aging population, we're going to need earlier and more effective genetic markers to determine where we can have impact on the disease earlier in life," Valentine said.

The findings were presented this weekend at the American Heart Association's annual meeting, in Philadelphia. Such research is considered preliminary until published in a peer-reviewed journal.

More information

The American Heart Association has more about atrial fibrillation.