More than 40% of Adults with No Known Heart Disease had Fatty Deposits in Heart Arteries

More than 40% of adults ages 50 to 64 years in Sweden without known heart disease were found to have some degree of atherosclerosis, according to a new study published today in the American Heart Association’s flagship journal Circulation.

Atherosclerosis, or the buildup of fatty deposits in blood vessels that supply blood to the heart, is a major cause of heart attacks. A widely used approach to screen people who are at risk for heart disease but who do not yet have symptoms is cardiac computed tomography, commonly known as a cardiac CT scan, for coronary artery calcification (CAC) scoring. The scan creates cross-sectional images of the vessels that supply blood to the heart muscle to measure the presence and density of calcium-containing plaque in the coronary arteries. Based on these scans, individuals are given a CAC “score” to estimate their risk for or extent of coronary artery disease. This score can be 0 to over 400. A CAC score of 400 or higher is associated with a high risk for having a heart attack, stroke or dying from either one within the next 10 years. However, CAC scoring can miss a percentage of people who are at risk for heart attack even though they have a zero CAC score.

“Measuring the amount of calcification is important, yet it does not give information about non-calcified atherosclerosis, which also increases heart attack risk,” said study author Göran Bergström, M.D., Ph.D., professor and senior consultant in clinical physiology in the department of molecular and clinical medicine at the University of Gothenburg’s Institute of Medicine in Gothenburg, Sweden.

Bergström and colleagues randomly recruited participants aged 50 – 64 years old from the Swedish census register from 2013 to 2018 as part of the Swedish CArdioPulmonary BioImage Study (SCAPIS). They report on data from 25,182 participants with no history of a prior heart attack or cardiac intervention who underwent both CAC scans and coronary computed tomography angiography (CCTA) scans . CCTA is a radiologic technique that gives a very detailed image of the inside of the arteries that supply the heart with blood. The researchers wanted to determine the prevalence of atherosclerosis in the general population without established heart disease, and how closely the CCTA findings correlated to CAC scores.

They found:

  • CCTA detected some degree of atherosclerosis in more than 42% of the study participants.
  • CCTA found that in 5.2% of those with atherosclerosis, the build-up obstructed blood flow through at least one coronary artery (out of three) by 50% or more.
  • In nearly 2% of those found to have artery build-up, the atherosclerosis was even more severe. Blood flow was obstructed to the main artery that supplies blood to large portions of the heart, and in some cases, all three coronary arteries were obstructed.
  • Atherosclerosis started an average of 10 years later in women compared to men.
  • Atherosclerosis was 1.8 times more common in people ages 60-64 vs. those ages 50-54.
  • Participants with higher levels of atherosclerosis seen by CCTA also had higher CAC scores.
  • Of those with a CAC score of more than 400, nearly half had significant blockage, where more than 50% of the blood flow was obstructed in one of the coronary arteries.
  • In those with a CAC score of zero, 5.5% had atherosclerosis detected by CCTA, and 0.4% had significant obstruction of blood flow.

“The current, 2019 American Heart Association/American College of Cardiology guideline for prevention of heart attacks states that adults with a zero CAC score and intermediate level of risk factors are at low risk of future heart attack. We found that 9.2% of people who fit that description had atherosclerosis in their coronary arteries visible by CCTA,” Bergström said. “One strength of CCTA is that not-yet calcified atherosclerosis can be detected. We found that 8.3% of the adults had one or more non-calcified plaques. Non-calcified atherosclerosis is believed to be more prone to cause heart attacks compared with calcified atherosclerosis.”

The AHA/ACC guideline Bergström mentions does not address the use of CCTA in heart attack prevention.

“It is important to know that silent coronary atherosclerosis is common among middle-aged adults, and it increases sharply with sex, age and risk factors,” according to Bergström. “A high CAC score means there is a high likelihood of having obstruction of the coronary arteries. However, more importantly, a zero CAC score does not exclude adults from having atherosclerosis, especially if they have many traditional risk factors of coronary disease.”

A limitation of the study is that it lacks follow-up information about how cardiovascular heart disease develops in this population, which makes it impossible to determine if these findings predict clinical heart disease in this population.

Source: American Heart Association

What Helps Your Heart More, Losing Fat or Gaining Muscle?

Alan Mozes wrote . . . . . . . . .

Shedding excess weight does much more for the long-term heart health of young people than building muscle, new research suggests.

It’s not that gaining muscle while young proved to be a cardiovascular problem. It’s just that losing fat offered bigger heart benefits.

“We absolutely still encourage exercise,” said study lead author Joshua Bell, a senior research associate in epidemiology at the University of Bristol in England.

“There are many other health benefits, and strength is a prize in itself,” he said. “We may just need to temper expectations for what gaining muscle can really do for avoiding heart disease. Fat gain is the real driver.”

The study followed more than 3,200 Brits born in the 1990s. It found those who had primarily lost fat during adolescence and young adulthood were much less likely than those who had gained muscle to develop risk factors such as high glucose, inflammation or “bad” cholesterol by age 25.

Participants had scans to assess levels of body fat and lean mass at ages 10, 13, 18 and 25. Handgrip strength tests were also assessed at 12 and 25.

At 25, participants underwent blood pressure and blood sample testing to assess levels of roughly 200 metabolic factors viewed as “a gateway for heart disease and other health problems,” Bell explained.

Such factors included insulin, C-reactive protein, cholesterol, triglycerides, glucose, creatinine and branched chain amino acids.

The result: For lowering risk factors for heart disease, “changes in body fat seem to matter much more than changes in muscle,” Bell said. By some measures — such as lowering levels of “bad” cholesterol — fat loss appeared to be as much as five times more protective than muscle gain, he added.

“Muscle gain only seemed beneficial when it happened in adolescence, between 13 and 18 years old,” Bell said. “This is a busy time of growth and maturity, and might be when we should promote some muscle gain as well. [Heart] benefits seem to fade after then.”

His bottom-line message: While muscle is important for outcomes like mobility and independence, fat control seems to be a higher priority when it comes to keeping markers for heart disease in check.

The results were published recently in PLOS Medicine.

Bell stressed that the findings are critical because the seeds of future heart trouble are sown among youths and adolescents, who are otherwise healthy.

While “serious events like heart attacks don’t tend to happen until older ages, heart disease doesn’t happen overnight,” Bell noted.

Lona Sandon is an associate professor in the school of health professions at UT Southwestern Medical Center in Dallas, and reviewed the study findings.

She said you should aim to prevent excess fat gain from the start, rather than focus on fat loss later.

“Instill healthy eating and activity habits early on to maintain a healthy body weight throughout childhood and adolescence for the best chance of reducing early onset of heart disease risk factors,” said Sandon. “And by early on, I mean in the womb and infancy.”

There should be focus on educating parents about healthy pregnancies and healthy feeding patterns, Sandon advised. “Start with breastfeeding and feeding healthy whole foods and age-appropriate portions during infancy and early childhood,” she said.

Restricting calories during childhood is generally not a good idea, as this is a time of growth, Sandon cautioned. “Calories and quality foods are needed for proper growth and development,” she said.

Instead, exercise and sports can be a great way to keep a growing body trim. “Active play goes a long way toward keeping kids fit without putting the focus on body fat,” Sandon stressed. “Also active kids may be more likely to carry over those active habits into adulthood.”

Source: HealthDay

Chemists Develop Foolproof New Test to Track the Fats We Eat

Michelle Donovan wrote . . . . . . . . .

A team of researchers at McMaster has developed a reliable and accurate blood test to track individual fat intake, a tool that could guide public health policy on healthy eating.

Establishing reliable guidelines has been a significant challenge for nutritional epidemiologists until now, because they have to rely on study participants faithfully recording their own consumption, creating results that are prone to human error and selective reporting, particularly when in the case of high-fat diets.

For the study, published in the Journal of Lipid Research, chemists developed a test, which detects specific non-esterified fatty acids (NEFAs), a type of circulating free fatty acid that can be measured using a small volume of blood sample.

“Epidemiologists need better ways to reliably assess dietary intake when developing nutritional recommendations,” says Philip Britz-McKibbin, professor in the Department of Chemistry & Chemical Biology at McMaster and lead author of the study

“The food we consume is highly complex and difficult to measure when relying on self-reporting or memory recall, particularly in the case of dietary fats. There are thousands of chemicals that we are exposed to in foods, both processed and natural,” he says.

The study was a combination of two research projects Britz-McKibbin conducted with Sonia Anand in the Department of Medicine and Stuart Phillips in the Department of Kinesiology.

Researchers first assessed the habitual diet of pregnant women in their second trimester, an important development stage for the fetus. The women, some of whom were taking omega-3 fish oil supplements, were asked to report on their average consumption of oily fish and full-fat dairy and were then tested with the new technology. Their study also monitored changes in omega-3 NEFAs in women following high-dose omega-3 fish oil supplementation as compared to a placebo.

Researchers were able to prove that certain blood NEFAs closely matched the diets and/or supplements the women had reported, suggesting the dietary biomarkers may serve as an objective tool for assessment of fat intake.

“Fat intake is among the most controversial aspects of nutritional public health policies given previously flawed low-fat diet recommendations, and the growing popularity of low-carb/high-fat ketogenic based diets,” says Britz-McKibbin.

“If we can measure it reliably, we can begin to study such questions as: Should pregnant women take fish oil? Are women deficient in certain dietary fats? Does a certain diet or supplement lead to better health outcomes for their babies?”

Researchers plan to study what impact NEFAs and other metabolites associated with dietary exposures during pregnancy, might have on childhood health outcomes in relation to the obesity, metabolic syndrome and chronic disease risk later in life.

Source: Brighter World

Western Diet Rich in Fat and Sugar Linked to Skin Inflammation

A Western diet rich in fat and sugar may lead to inflammatory skin diseases such as psoriasis, a study by UC Davis Health researchers has found.

The study, published today in Journal of Investigative Dermatology, suggests that dietary components, rather than obesity itself, may lead to skin inflammation and the development of psoriasis. A common and chronic skin disease, psoriasis causes skin cells to form scales and red patches that are itchy and sometimes painful.

Diet and Skin Inflammation

Previous studies have shown that obesity is a risk factor for the development or worsening of psoriasis. The Western diet, characterized by a high dietary intake of saturated fats and sucrose and low intake of fiber, has been linked to the increased prevalence of obesity in the world.

“In our study, we found that short-term exposure to Western diet is able to induce psoriasis before significant body weight gain,” said Sam T. Hwang, professor and chair of dermatology at UC Davis and senior author on the study.

For the UC Davis Health study, which used a mouse model, Hwang and his colleagues found that a diet containing both high fat and high sugar (mimicking the Western diet in humans) was required to induce observable skin inflammation. In four weeks only, mice on Western diet had significantly increased ear swelling and visible dermatitis compared to mice fed a controlled diet and those on high fat diet alone.

“Eating an unhealthy diet does not affect your waistline alone, but your skin immunity too,” said Zhenrui Shi, visiting assistant researcher in UC Davis Department of Dermatology and lead author on the study.

Bile Acids and Skin Inflammation

The study detailed the mechanisms by which inflammation happens following a Western diet. It identified bile acids as key signaling molecules in the regulation of skin immunity. Bile acids are produced in the liver from cholesterol and metabolized in the intestine by the gut microbiota. They play an important role in dietary lipid absorption and cholesterol balance in the blood.

The study found that cholestyramine, a drug used to lower cholesterol levels by binding to bile acids in the intestine, helped reduce the risk of skin inflammation. The finding suggests that bile acids mediate the development of psoriasis. The binding of cholestyramine to bile acids in the gut and its subsequent release through the stool allows for lowering of skin inflammation.

Further studies are needed to understand the mechanism behind diet-induced skin inflammation and the interaction between metabolism, microbes and immunity.

Source: UC Davis

Study: Fat Accumulates in the Lungs of Overweight and Obese People

Researchers have shown for the first time that fatty tissue accumulates in the airway walls, particularly in people who are overweight or obese.

Scientists already know that people who are overweight or obese are more likely to suffer with wheezing and asthma, but the reasons for this have not been completely explained.

The new study, published in the European Respiratory Journal, suggests that this fatty tissue alters the structure of people’s airways and this could be one reason behind the increased risk of asthma.

The study’s author is Mr John Elliot, a senior research officer at Sir Charles Gairdner Hospital in Perth, Western Australia. He said: “Our research team studies the structure of the airways within our lungs and how these are altered in people with respiratory disease.

“Looking at samples of lung, we spotted fatty tissue that had built up in the airway walls. We wanted to see if this accumulation was correlated with body weight.”

The researchers examined post-mortem samples of lung that had been donated for research and stored in the Airway Tissue Biobank. They studied samples from 52 people, including 15 who had no reported asthma, 21 who had asthma but died of other causes and 16 who died of asthma.

Using dyes to help visualise the structures of 1373 airways under a microscope, they identified and quantified any fatty tissue present. They compared this data with each person’s body mass index (BMI).

For the first time, the study showed that fatty tissue accumulates in the walls of the airways. The analysis revealed that the amount of fat present increases in line with increasing BMI. The research also suggests that this increase in fat alters the normal structure of the airways and leads to inflammation in the lungs.

Co-author, Dr Peter Noble, an associate professor at the University of Western Australia in Perth said: “Being overweight or obese has already been linked to having asthma or having worse asthma symptoms. Researchers have suggested that the link might be explained by the direct pressure of excess weight on the lungs or by a general increase in inflammation created by excess weight.

“This study suggests that another mechanism is also at play. We’ve found that excess fat accumulates in the airway walls where it takes up space and seems to increase inflammation within the lungs. We think this is causing a thickening of the airways that limits the flow of air in and out of the lungs, and that could at least partly explain an increase in asthma symptoms.”

The team are looking for new ways to study and measure fatty tissue in the lungs. They want to confirm the relationship with respiratory disease and to find out whether the effect can be reversed by weight loss therapy.

Professor Thierry Troosters is President of the European Respiratory Society and was not involved in the study. He said: “This is an important finding on the relationship between body weight and respiratory disease because it shows how being overweight or obese might be making symptoms worse for people with asthma. This goes beyond the simple observation that patients with obesity need to breathe more with activity and exercise hence adding to their ventilatory burden. The observation points at true airway changes that are associated with obesity.

“We need to investigate this finding in more detail and particularly whether this phenomenon can be reversed with weight loss. In the meantime, we should support asthma patients to help them achieve or maintain a healthy weight.”

Source: European Respiratory Society