An alarming number of adults in the U.S. are at risk of heart syndrome

Nearly 90% of adults over age 20 in the United States are at risk of developing heart disease, an alarming new study suggests.

While the unexpectedly high number doesn't mean that the majority of adults in the U.S. have full-blown heart disease, it does indicate that many are at risk of developing the condition, even younger people.

Researchers identified people at high risk using a recently defined syndrome that takes into account the strong links between heart disease, obesity, diabetes and kidney disease, according to the research published Wednesday in JAMA.

The American Heart Association alerted doctors in October about cardiovascular-kidney-metabolic (CKM) syndrome, a condition which affects major organs in the body, including the brain, heart, liver and kidneys. CKM is diagnosed in stages ranging from zero — no risk factors for heart disease — to 4 — people with diagnosed heart disease plus excess body fat, metabolic risk factors such as hypertension and diabetes, or kidney disease.

For the new study, researchers analyzed almost a decade’s worth of data from more than 10,000 people who were participating in the National Health and Nutrition Examination Survey (NHANES).

“We absolutely were surprised that almost 90% of people met the criteria,” said study co-author Dr. Rahul Aggarwal, a cardiology fellow at Brigham and Women’s Hospital, Harvard Medical School, in Boston. “It was much higher than we anticipated in a database that included younger adults.”

Especially concerning was the finding that almost 50% of the NHANES participants were at stage 2 of CKM, meaning that they were at moderate risk because they had either high blood sugar, hypertension, high cholesterol or chronic kidney disease, Aggarwal said.

Just more than a quarter of the group — people listed as stage 1 — were at increased risk of developing heart disease because of being obese or overweight, having excess belly fat and fat around their organs, but didn't have specific symptoms.

The researchers found that 15% of the participants had advanced disease, a number that remained fairly constant between 2011 and 2020.

“I think one of the biggest factors contributing to the fact that the percentage of people in advanced stages is not improving is obesity, which is very prevalent in the U.S.,” Aggarwal said, adding that 40% of people in America are obese. Another 32% are overweight based on body mass index calculations, according to the Centers for Disease Control and Prevention.

Carrying excess pounds increases the likelihood a person will have high blood pressure, high blood sugar and high cholesterol, although some have metabolic risk factors even if they are at a healthy weight.

Participants older than 65 were more likely to be at an advanced stage than people between 45 to 64. But being young wasn’t as protective as one might assume. Only 18% of people ages 20 through 44 were at stage zero. That is, they had no risk factors.

The new findings show that health care providers need to be picking up on these conditions earlier “before they lead to downstream effects,” such as increased risk of heart attack, heart failure and stroke, Aggarwal said. “We need to diagnose earlier and be more aggressive at treating people.”

Adopting lifestyle changes, such as improved diets and increased activity, can help protect against heart attack and stroke.

The findings also show that “young adults, those younger than 45, are not as healthy as we thought they were,” Aggarwal said.

Experts were also surprised by the high rates of CKM.

“It is alarming that 90% of the population is at least stage 1 and only 10% have no risk factors,” said Dr. Sripal Bangalore, a professor of medicine and director of invasive and interventional cardiology at NYU Langone Health in New York City.

He blames the epidemic of overweight and obesity for those numbers.

“We have a lot of work to do to reduce the rates of overweight and obesity,” Bangalore said. “If we can do that, then hopefully we can reduce the number of people who progress to stage 2 and also move the needle down for higher stages.”

The inclusion of kidney disease in the risk assessments for cardiovascular disease makes a lot of sense, said Dr. Adriana Hung, a kidney specialist and epidemiologist and a professor of medicine at the Vanderbilt University Medical Center in Nashville, Tennessee.

“Kidney disease magnifies cardiovascular disease,” she said. “Some studies show that a patient has as much as six times the risk of dying from cardiovascular disease if kidney disease is also present.”

The new, broader approach to heart disease is likely to help identify more people who are at risk, said Dr. Robert Rosenson, director of lipids and metabolism for the Mount Sinai Health System in New York City.

“The main message from this study should be that many common behaviors are leading to an accumulation of diseases over one’s lifetime, which will impact quality of life and survival,” he said.

The large numbers of people with CKM in this study are related to overweight and obesity, insulin resistance and a diet that is high in fat and salt, Rosenson added.

People need to realize that it’s not just the heart that is being harmed by unhealthy diets and lack of exercise, he said, but that lifestyle factors also have an effect on cognition.