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  • New research indicates that Americans with high cholesterol are likely to be unaware of their condition.
  • High cholesterol is also more prevalent among certain races and individuals of lower socioeconomic status.
  • There’s more work to do in improving awareness of the condition, particularly in underserved communities.

Americans are making modest gains in the battle against high cholesterol, but knowledge gaps on the subject are still widespread, especially for underserved communities.

High cholesterol is a major contributor to cardiovascular disease (CVD), and remains a prevalent issue in the United States. But, new research indicates that adults are improving their cholesterol levels.

Moreover, public health messaging about cholesterol appears to be working as well, with more adults learning about and seeking treatment for high cholesterol. However, certain groups, including Hispanic, Black, undereducated, and low-income individuals, are still behind the curve.

In a research letter published November 1 in the medical journal JAMA Cardiology, investigators wanted to look at the relationship between high cholesterol, awareness, and treatment. That is, how many people with high cholesterol actually know they have it? And if they know, do they seek treatment?

Those are important questions because high cholesterol is a “silent” risk factor for more serious CVD down the line. It has no identifiable symptoms, meaning you won’t know you have it unless you get your cholesterol levels checked.

Using the National Health and Nutrition Examination Survey (NHANES), a program designed to assess the general health of Americans, researchers pulled roughly twenty years of participant data from between 1999 to 2020. The NHANES utilizes two-year survey cycles, so the time period accounts for 10 of these cycles. The research included 23,667 participants who were 20 years or older at the time of enrollment.

Within this group, 1,851 (about 8%) had clinically “high” LDL cholesterol (160-189 mg/dl), and 669 (about 3% ) had “very high” LDL cholesterol (190 mg/dl or greater). Additionally, researchers classified individuals according to the knowledge of their condition. They were considered “unaware” if they had never had their LDL cholesterol checked or were never informed of having high cholesterol. Individuals were defined as “untreated” if they were never prescribed a medication for high cholesterol, such as a statin.

People in the high range who were both unaware and untreated fell from 52.1% to 42.7%. Those in the very high range also fell from 40.8% to 26.8%.

The trend, although heading in the right direction, is deceptive: those numbers are still unacceptably high.

“Our findings show that awareness and treatment of very high levels of LDL cholesterol (bad cholesterol) remain very low in the United States,” Dr. Salim Virani, PhD, one of the authors of the letter, and Vice Provost and Professor at The Aga Khan University in Pakistan, and Adjunct faculty at the Texas Heart Institute and Baylor College of Medicine, told Healthline.

There’s both good and bad news indicated in the research letter, so let’s start with the good.

“The good news is that over time, this study has found that the prevalence of severely elevated cholesterol and specifically LDL cholesterol, which we know is causal in heart disease, has declined over time. And I think that’s due to a lot of factors, including just greater awareness,” Dr. Fatima Rodriguez, Associate Professor of Medicine at Stanford University, told Healthline. Rodriguez is not affiliated with the research.

From 1999 to 2020, the prevalence of clinical “high” cholesterol decreased from 12.4%, representing 21.5 million adults, down to 6.1%, or 14 million people, in 2020 after controlling for age.

The number of people with “very high” cholesterol also dropped from 3.8% (6.6 million people) in 1999 down to 2.1% (4.8 million people) in 2020.

What does that mean?

One in 17 US adults has high LDL cholesterol and one in 48 has very high LDL cholesterol. More than 40% of individuals with high cholesterol don’t know they have it and don’t treat it.

Additionally, about one in four people with very high cholesterol are unaware of their condition and are not getting treatment for it.

Those numbers are “alarmingly high” said Rodriguez.

“What this work highlights is that we really want to check people’s cholesterol before they have problems and make sure that they understand that high cholesterol is an important risk factor and that it could be very effectively treated with cholesterol-lowering medications,” she told Healthline.

And that’s just part of the bad news.

The letter also indicates that there are large disparities in terms of cholesterol levels and awareness among certain ethnicities and individuals with low socioeconomic standing. Black and Hispanic people are more likely to have higher LDL cholesterol levels than their white counterparts. Not graduating high school, lack of health insurance, and low income are also predictors of having high cholesterol.

“We’re still way off target,” said Dr. Eduardo Sanchez, Chief Medical Officer for Prevention at the American Heart Association. Sanchez wasn’t affiliated with the research.

Sanchez said that the AHA’s own research has corroborated and verified similar findings.

“There is a gap in knowledge that could and should be addressed. Those gaps are not evenly borne out. There is a race and ethnicity differential disparity, and there is a differential associated with low household income and low educational level,” he said.

The issue of socioeconomic status and cardiovascular outcomes was examined in depth in a 2018 issue of Circulation.

“Low socioeconomic status has been linked to the development of CVD and may confer a cardiovascular risk that is equivalent to traditional risk factors,” wrote the authors.

They looked at four specific socioeconomic areas to make that determination: education level, employment, income, and environmental factors. Each one is responsible for a meaningful increase in CVD risk. Additionally, individuals with low socioeconomic standing were also found to have worse outcomes if and when they become sick.

In 2019, the AHA and more than ten other health organizations outlined the inclusion of ethnicity as a risk factor that must be included in cholesterol guidelines. Virani was a member of the committee involved in issuing those guidelines.

“We’ve got some work to do to lessen the gap in terms of awareness about and treatment of elevated LDL and that’s something that our organization is committed to doing,” said Sanchez

On the other hand, gains made via increased cholesterol screening and increased adoption of cholesterol-lowering medications are also consistent in other research.

A study in the Journal of the American Heart Association, published in 20213, looked at these trends in more than 50,000 US adults again by using NHANES data between 1999 and 2018. Researchers identified four promising trends from that data. In the past twenty years:

  • Cholesterol screening has increased
  • Average total cholesterol have dropped
  • More people are using cholesterol medications
  • Average LDL cholesterol levels have also decreased

CVD remains the number one killer in the United States. Unfortunately, CVD can rarely be traced to a single risk factor. Lifestyle, diet, genetics, smoking, high blood pressure, and family history all play a role in its development. Of the many risk factors for CVD, high cholesterol is a known culprit.

People with high cholesterol, identified as greater than 200 mg/dl total blood cholesterol or 160 mg/dl or greater LDL cholesterol are at greater risk of CVD.

LDL cholesterol is often called “bad” cholesterol, whereas high-density lipoprotein (HDL) cholesterol is “good” because it takes cholesterol out of circulation and carries it back to the liver.

“It’s all about the LDL in terms of risk,” said Rodriguez. She says that people should think about LDL cholesterol as an indicator similar to A1C for diabetes, and get it checked routinely.

“Have your LDL levels checked regularly, especially when they’re elevated at least once, and begin this process really early in life. We know that cholesterol, just like exposure to tobacco, is something that builds up over time,” said Rodriguez.

New research shows that Americans have, on average, improved their LDL cholesterol levels over the past 10 years.

Despite this trend, high cholesterol is still widespread, and significant improvements need to happen on both and individual and healthcare-wide level.

A significant number of people with high or very high cholesterol are unaware of their condition and leave it untreated.

Socioeconomic factors are contributors to cardiovascular health, and certain groups of people, including Black and Hispanic people are likely to have worse outcomes from cardiovascular disease.