Roundup: Abdominal Fat May Be More Reliable Than BMI for Determining Cardiovascular Risks; and More News

Abdominal Fat May Reveal Heart Risk That BMI Misses, Research Finds

For decades, body mass index has been a common tool for assessing whether a person’s weight may affect their health. But new research suggests BMI alone can miss an important part of the picture: where body fat is stored.

A large study published in the Journal of the American College of Cardiology (JACC) found that waist circumference and waist-to-hip ratio — or indicators of abdominal fat — can provide additional information about a person’s risk for heart disease, stroke and other serious health problems.

Looking Beyond BMI

BMI, or body mass index, estimates body size using a person’s height and weight. It is commonly used to classify adults as having normal weight, overweight or obesity.

Researchers examined data from 259,388 adults who did not have coronary heart disease when they entered the study. The analysis combined 15 long-term studies supported by the National Institutes of Health and the National Heart, Lung, and Blood Institute. Participants were followed for a median of 20 years.

The researchers compared BMI with two measures of “central adiposity,” meaning fat concentrated around the abdomen: waist circumference and waist-to-hip ratio.

The measures did not always agree. Among people whose BMI placed them in the normal-weight category, 5 percent had an elevated waist circumference and 18 percent had an elevated waist-to-hip ratio. Conversely, some participants with obesity had relatively low measurements of abdominal fat.

Abdominal Fat Linked to Higher Cardiovascular Risk

Among adults classified as normal weight or overweight, having a high waist circumference or waist-to-hip ratio was generally associated with a 15 percent to 50 percent greater risk for most of the health outcomes studied.

Those outcomes included heart attack, stroke, heart failure, atrial fibrillation, coronary heart disease, cardiovascular death and death from any cause. Heart failure occurs when the heart cannot pump enough blood to meet the body’s needs. Atrial fibrillation, or AFib, is an irregular heartbeat that can increase the risk of stroke.

The findings suggest that two people with the same BMI may have different cardiovascular risks depending on how their body fat is distributed.

Waist Measurements Could Add Useful Information

Abdominal fat also appeared important among people with obesity. Elevated waist circumference was associated with nearly half of heart failure and AFib events in this group. Participants with obesity but a low waist circumference generally had cardiovascular risk similar to normal-weight participants who also had a low waist circumference.

The researchers said the results do not make BMI useless. Instead, simple waist measurements may help clinicians identify risks that BMI alone can overlook.

The study supports considering abdominal fat distribution across all BMI categories when assessing cardiovascular risk. For consumers, the key message is that weight is only one measure of health. Where the body stores fat may also provide important information about long-term heart health.

Genetic Cholesterol Risk — Not Found in Standard Blood Tests — May Affect 1 in 5 People

A cholesterol-related particle that is largely inherited may raise the risk of stroke and cardiovascular death even when standard cholesterol results appear normal, according to a large new analysis.

Researchers examined data from more than 20,000 adults who participated in three major National Institutes of Health (NIH) clinical trials. They found that very high levels of lipoprotein(a), or Lp(a), were associated with a greater risk of serious cardiovascular events.

The findings were presented at the Society for Cardiovascular Angiography & Interventions 2026 Scientific Sessions and a Canadian interventional cardiology meeting in Montreal.

What is Lp(a)?

Lp(a) is a particle in the blood that carries cholesterol. It is similar to low-density lipoprotein, or LDL—the type commonly called “bad” cholesterol—but contains an additional protein that may contribute to cardiovascular disease.

Unlike many cholesterol levels, Lp(a) is determined primarily by genetics and generally remains fairly stable throughout life. About 1 in 5 people has a high Lp(a) level, according to the American Heart Association.

Elevated Lp(a) usually causes no symptoms. It also may not be detected through a standard cholesterol panel, so people can have high levels without knowing it.

Researchers Find Higher Cardiovascular Risk

Researchers analyzed stored blood samples from 20,070 adults ages 40 and older who had participated in the NIH-funded ACCORD, PEACE and SPRINT trials. The participants were about 65 years old on average and were followed for a median of nearly four years.

Researchers measured participants’ Lp(a) and tracked major cardiovascular events, including heart attack, stroke, procedures to restore blood flow to the heart and cardiovascular death.

During follow-up, 1,461 participants experienced one of these events.

People with Lp(a) levels of at least 175 nanomoles per liter had a 31 percent higher risk of a major cardiovascular event compared with people with lower levels, after researchers accounted for other factors. They also had a 64 percent higher risk of stroke and a 49 percent higher risk of cardiovascular death.

Very high Lp(a), however, was not associated with a significantly greater risk of heart attack in this analysis. The link between elevated Lp(a) and cardiovascular events was also stronger among people who already had heart disease.

A Blood Test Can Identify Elevated Lp(a)

Lp(a) can be measured with a specific blood test, in addition to standard cholesterol testing. Because levels are mostly inherited, testing may uncover cardiovascular risk that routine cholesterol measurements do not identify.

Currently, managing elevated Lp(a) generally focuses on reducing other modifiable cardiovascular risks, including lowering LDL cholesterol and controlling factors such as high blood pressure, diabetes and smoking.

Researchers said additional studies are planned in people with conditions including chronic kidney disease and peripheral artery disease, which occurs when narrowed arteries reduce blood flow to the limbs. Treatments designed specifically to lower Lp(a) are also under investigation.

Frequent TV Watching in Midlife Linked to Brain Changes Later in Life

Watching a lot of television in middle age may be associated with changes in brain structure that are linked to memory loss and dementia, according to a new study supported by the National Institutes of Health.

The findings suggest that brain health may depend not only on how much time people spend sitting, but also on what they do while seated.

Researchers Followed Adults for More Than 20 Years

The study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, analyzed data from about 1,700 adults participating in the long-running Atherosclerosis Risk in Communities study. Participants were about 53 years old, on average, when they entered the study between 1987 and 1989.

At enrollment, participants reported how often they watched television during their leisure time, with responses ranging from “never or seldom” to “very often.” They also reported how much of their workday they spent sitting.

More than two decades later, participants underwent magnetic resonance imaging, or MRI, a noninvasive scan that provides detailed images of the brain.

Heavy TV Viewing Associated with Smaller Brain Regions

Compared with people who reported rarely or never watching television, those who said they watched TV very often had smaller volumes in several areas of the brain.

These included regions involved in memory and areas where changes can appear early in Alzheimer’s disease. Frequent TV viewers also had smaller frontal lobes, which help with planning, decision-making and other complex mental tasks, and smaller occipital lobes, which are important for processing visual information.

Researchers also found more “white matter hyperintensities” among frequent TV viewers. These are areas that appear unusually bright on certain MRI scans and can indicate damage to the brain’s small blood vessels. Greater amounts of this damage have been associated with aging, stroke, problems with thinking and memory, and dementia.

The associations remained after researchers accounted for factors including exercise, diabetes, body mass index, smoking and alcohol use.

Sitting Itself May Not Explain The Findings

Interestingly, sitting at work was not associated with the same brain differences. Participants who spent more time sitting on the job showed some signs of better brain structure than frequent television viewers.

Researchers said one possible explanation is that many seated jobs involve greater mental stimulation than watching television. The study, however, was not designed to prove why the differences occurred.

The associations also appeared stronger among men than women, an observation researchers say requires further study.

Study does not Prove TV Causes Dementia

The findings show an association, not cause and effect. Researchers relied on participants to report their own television habits, which may not always be accurate. Participants also did not receive brain MRIs at the beginning of the study, so researchers could not directly measure how their brains changed over time.

More research is needed to determine whether reducing television viewing or replacing it with mentally engaging activities can protect brain health. For now, the study suggests that when considering the health effects of sitting, the activity occupying that time may matter as well.