Heart health and physical activity

New research, appearing in the European Heart Journal, suggests that lack of physical activity can drastically increase the risk of a heart attack in the long-term, even if there are no symptoms at present.
running and heart fitness
Exercise that raises the heart rate, such as running, may cut heart attack risk by half, suggests a new study.

Cardiorespiratory fitness describes the body’s ability to deliver oxygen to the muscles when we are engaged in physical activity. Specifically, the term refers to “the efficiency of the heart, lungs and vascular system.”

A significant body of research has linked cardiorespiratory fitness with a variety of positive health outcomes, ranging from preventing cardiovascular disease and all-cause mortality to staving off diabetes and improving insulin resistance.

However, most of these previous studies have relied on the participants’ self-reported levels of fitness.

New research uses more precise methods of measuring cardiorespiratory fitness and highlights another one of its benefits.

Higher fitness levels can halve the risk of heart attack, the new study finds. Conversely, suggest the researchers, poor fitness levels can raise future risk even in the absence of warning symptoms in the present.

Bjarne Nes, from the Norwegian University of Science and Technology’s Cardiac Exercise Research Group in Trondheim, is the corresponding and last author of the study.

Studying fitness levels and heart attack risk

Nes and his colleagues analyzed the cardiorespiratory fitness of more than 4,500 people who took part in an extensive health survey called HUNT3.

None of the participants had a history of cardiovascular disease, lung disease, cancer, or high blood pressure at the start of the study.

Just over 50 percent of the participants were women, and more than 80 percent of all of them were at “low risk” of developing cardiovascular disease over a 10-year period.

The scientists used a “gold-standard method” — or maximum oxygen uptake — to directly measure the participants’ fitness levels.

Maximum oxygen uptake refers to the maximum amount of oxygen the body can absorb during exercise. According to Nes, it is “the most precise measure of fitness.”

High fitness halves the risk of heart attack

By the end of the study, 147 of the participants had heart attacks or had developed angina pectoris — two conditions caused by blocked or narrowed coronary arteries.

The analysis by the researchers revealed a correlation between declining cardiovascular risk and increased fitness levels.

“Even among people who seem to be healthy, the top 25 percent of the most fit individuals actually have only half as high a risk as the least fit 25 percent,” reports Nes.

Furthermore, even a small improvement in cardiorespiratory fitness saw significant benefits for heart health. Namely, each fitness increase of 3.5 points correlated with a 15 percent lower risk of heart attack or angina.

“We found a strong link between higher fitness levels and a lower risk of heart attack and angina pectoris over the 9 years following the measurements that were taken,” says Nes.

“We know that patients with low oxygen uptake are at increased risk of premature death and cardiovascular disease,” he continues.

Our study shows that poorer fitness is an independent risk factor for coronary artery disease, even among healthy women and men who are relatively fit.”

Bjarne Nes

‘Use training as preventive medicine’

Dr. Jon Magne Letnes, the study’s first author, also further comments on the findings. “Our results should encourage people to use training as preventive medicine,” Dr. Letnes says.

“A few months of regular exercise that gets you out of breath can be an effective strategy for reducing the risk of cardiovascular disease.”

Dr. Letnes explains that cardiorespiratory fitness offers insights into so much more than just endurance to exercise.

“Fitness isn’t just a measure of how much you’ve trained in your life, but it also tells you what kind of genes you have,” he says.

“Other factors like obesity may also affect fitness. So we measure a lot of the body’s functions, and from other studies, we know that both genes and physical activity play a role in how your heart and blood vessels function,” Dr. Letnes explains.

The study’s first author thinks doctors should consider fitness measurements when evaluating heart disease risk.

“Although it may be inconvenient and difficult to measure oxygen uptake at the doctor’s office, some simple and relatively accurate calculators exist that can provide a good estimate of fitness and disease risk,” he advises.

New Obesity procedure

New obesity procedure appears to also reduce muscle mass.  A study about a new obesity procedure for the treatment of obesity has raised some concerns. This is because, while the treatment leads to weight loss, the pounds a person sheds consist of skeletal muscle as well as fat. Also, body fat loss seems to be mainly of the subcutaneous — as opposed to the riskier visceral — type.
obesity procedure doctor taking measurements of obese man
Visceral fat can harm health, and some people with obesity resort to surgical procedures to remove it.

Skeletal muscle is necessary for good health; its loss can result in not only physical problems, but it can also impair metabolism and raise the risk of injury.

Visceral fat is the type of fat that surrounds the organs deep inside the abdomen. Doctors have linked carrying too much of it to health problems, such as type 2 diabetes and heart disease.

The new obesity procedure is called left gastric artery embolization. Interventional radiologists have been using it for decades to stop bleeding in emergencies.

However, the idea of using gastric artery embolization to treat obesity is new, and clinical trials are currently evaluating its safety and effectiveness for such a purpose.

The aim of the new obesity procedure treatment is to reduce the effect of an appetite hormone by injecting microscopic beads to block an artery that supplies blood to the stomach.

The study’s findings featured recently at the annual meeting of the Radiological Society of North America that is currently taking place in Chicago, IL.

Need for new cost-effective, low-risk obesity procedures

Study lead author Dr. Edwin A. Takahashi, who is a vascular and interventional radiology fellow at the Mayo Clinic in Rochester, MN, explains that a lot of research has shown that gastric artery embolization can achieve weight loss.

“However,” he adds, “there has been no data on what is contributing to the weight loss, whether the patients are losing fat, as desired, or muscle mass, or some combination of the two.”

Obesity is a significant global public health issue with links to heart disease, type 2 diabetes, cancer, and other serious illnesses and health problems.

Rates of obesity and being overweight have almost tripled worldwide over the last 40 years, according to the World Health Organization (WHO).

The WHO estimates for 2016 suggest that being overweight affects more than 1.9 billion of the world’s adults. This figure includes some 650 million adults with obesity.

While changes to lifestyle factors such as diet and physical activity can work, for many people, these are not enough, and they opt to undergo weight-loss operations that reduce the size of the stomach.

Such surgical procedures have proved effective as treatments for obesity, but they are costly and carry risks and complications.

Left gastric artery embolization

Left gastric artery embolization — if found to be effective and safe — could offer people a less invasive option for the treatment of obesity.

The obesity procedure involves injecting microscopic beads into the artery that delivers blood to the stomach. The radiologist inserts a catheter either in the wrist or groin and uses imaging to reach the artery.

Once released into the artery, the microbeads block the flow of blood through the smaller blood vessels to the stomach. This has the effect of reducing production of ghrelin, a hunger-stimulating hormone.

Early trials have shown promising results that the procedure can help people lose weight. However, there is little information about where the weight loss comes from, and how it affects body composition of fat and muscle.

Dr. Takahashi and his team examined computed tomography scans of 16 overweight people, some with obesity, who had undergone left gastric artery embolization to stop bleeding.

With help from special software that analyzes tissue density, they assessed fat and muscle composition on scans taken before and about 1.5 months after the treatment.

Results raised some concerns by new obesity procedure

All 16 of the individuals who underwent embolization lost a significant amount of weight afterward. On average, they lost 6.4 percent of their body weight in the ensuing 1.5 months.

Their body mass index (BMI) fell by 6.3 percent over the same period.

The weight loss came as no surprise to the researchers; however, what did surprise them was the alteration in body composition.

They calculated that skeletal muscle index reduced by 6.8 percent. This index reflects the quantity of muscle in the body that is attached to bone and helps the movement of limbs and other body parts.

Loss of skeletal muscle can not only reduce physical function, but it can also damage metabolism and raise the risk of injury.

“The significant decrease in the amount of skeletal muscle,” says Dr. Takahashi, “highlights the fact that patients who undergo this procedure are at risk for losing muscle mass and need to be managed accordingly after [the] procedure.”

We must make sure they receive adequate nutrition to minimize the amount of muscle tissue they lose.”

Dr. Edwin A. Takahashi

The results also showed that the individuals lost a lot of body fat; there was an average drop of 3.7 percent in body fat index.

However, most of the body fat loss was due to the reduction in subcutaneous fat. Loss of visceral fat was insignificant over the follow-up.

Subcutaneous fat is all over the body under the skin. Visceral fat is fat that surrounds the organs deep in the abdominal cavity.

Science “has been distinctly linked” carrying excessive amounts of visceral fat to several health problems and conditions. These include impaired metabolism, insulin resistance, increased risk to certain cancers, prolonged hospitalization, and higher risk of complications.

The team now want to focus further studies on individuals who undergo left gastric artery embolization specifically to treat obesity.