Nine of 10 American adults are in the early, middle or late stages of a syndrome that leads to heart disease, a new report finds, and almost 10% have the disease already.

"Poor cardiovascular, kidney, and metabolic health is widespread among the U.S. population," concludes a team led by Dr. Muthiah Vaduganathan of Brigham and Women’s Hospital and Harvard Medical School in Boston.

Researchers looked specifically at rates of what the American Heart Association has dubbed cardiovascular, kidney and metabolic (CKM) syndrome — interrelated factors that progress with time and, if left unchecked, lead to heart disease.

CKM syndrome is divided into four stages:

• Stage 1: Excess fat buildup in the body (a risk factor for poor health)

• Stage 2: Emergence of other metabolic risk factors (for example, high blood pressure, high cholesterol, diabetes)

• Stage 3: Emergence of high-risk kidney disease and/or a high predicted risk of heart disease being diagnosed within the next 10 years 

• Stage 4: A diagnosis of full-blown heart disease, with or without kidney disease

To find out how many Americans might fall into one of these four categories, the Boston team tracked U.S. federal health survey data for 2011 through 2020.

Among adults age 20 or older, only 10.6% did not have some level of CKM syndrome, the researchers reported May 8 in the Journal of the American Medical Association. 

About 26% fell into the early stage 1 category, meaning they were gaining dangerous levels of body fat. Nearly half (49%) of adults fell into stage 2 CVM syndrome, and 5.4% were stage 3.

According to the study, 9.2% of adults were in stage 4, with full-blown heart disease and, in some cases, failed kidneys.

All of these numbers were roughly unchanged throughout the nine-year study period.

Not surprisingly, the severity of CKM syndrome rose with age: 55.3% of people 65 or older were in an advanced stage of CKM syndrome, compared to 10.7% of those aged 45 through 64, and 2.1% of those aged 20 through 44, the study found.

The young were at risk, too. Most Americans ages 20 through 44 (81.8%) were already affected by these heart and kidney risk factors, Vaduganathan's team noted. 

Race also mattered, with Black Americans 38% more likely to be burdened with CKM syndrome compared to whites. 

The bottom line: "Almost 90% of US adults met criteria for CKM syndrome (stage 1 or higher) and 15% met criteria for advanced stages, neither of which improved between 2011 and 2020," according to the Boston researchers.