One-third of the high school, college and professional athletes who were screened by the Stanford sports cardiology clinic register as having high blood pressure, Stanford researchers have found.
These people are young and fit, with exercise habits that put the rest of us to shame. How can so many have elevated blood pressure?
- New blood pressure guidelines, issued by the American College of Cardiology and the American Heart Association in November 2017, are too low;
- Some of the athletes with elevated blood pressure have white coat syndrome, or nervousness during testing that raises blood pressure; and/or
- The athletes tested have hypertension.
"There are a lot of inputs into hypertension -- for example, genetics, body composition and diet -- and just because you're an athlete you're not excluded," Moneghetti said. "But it also depends on how you measure blood pressure. We may just be having a whole lot of false positives."
Until November 2017, the guidelines stated that blood pressure readings should be under 140/90; now, they say readings such be under 130/80. European guidelines remain at the 140/90 level.
It's in that gray area, between the current U.S. and European guidelines, that most of the athletes in the study with elevated blood pressure fell: only 9% had readings over 140/90.
Moneghetti; Kristofer Hedman, MD, PhD, a postdoctoral fellow; and other researchers gathered data from 2,733 athletes ages 13 to 35 who visited the Stanford sports cardiology screening program from 2010 to 2016, most to be screened for their risk of sudden cardiac death. They participated in 35 different sports, including football, track, water polo, basketball, fencing, crew and volleyball; about two-thirds were male.
The researchers found that 34% exceeded the current U.S. hypertension levels. The male athletes had a higher chance of elevated blood pressure, as did athletes with a high body mass index. Moneghetti said they weren't able to distinguish between high BMI due to adipose tissue, or fat, or a high BMI due to musculature, neither of which is uncommon among football players.
Moneghetti cautioned that the athletes had their blood pressure measured during only one visit, and to make a diagnosis of hypertension, measurements need to be taken on at least two separate occasions. However, some of the athletes with elevated blood pressure showed changes in heart structure and function, suggesting that they had suffered from elevated blood pressure for a while. "This is somewhat worrying, considering their young age," Hedman said.
Moneghetti said that he'd like to follow the athletes who had gray-area hypertension to see if it develops into full-blown hypertension: "We're trying to develop a mechanism to follow them over time," he said. "But they move around a lot, so it's difficult."
Photo by Matt Lee