Strengthen muscles can be healthier than losing fat

Investigating muscle building rather than fat loss may be a better way to protect ourselves from weight-related hazards such as diabetes and cardiovascular disease.

They hypothesize that poor skeletal muscle health is a major factor such as poor diet, physical inactivity and stress reduce our sensitivity to insulin, placing us at risk for diabetes and increasing early markers cardiovascular diseases such as stiffening of the arteries.

Medical College of Georgia investigators think this is bad for all of us, but it can also help explain even higher rates – and more severe cases – of these common black diseases.

If they are right, measuring muscle health rather than fat would be a more accurate indicator of how we are doing with the genetics we are born with and the lifestyles we choose.

It could also make resistance training, which contracts our muscles, a new goal in the fight to stay healthy, says Dr. Ryan A. Harris, physiologist for clinical exercise and vascular disease at the MCG Georgia Prevention Institute and the Department of Medicine.

Dr. Xiaoling Wang, a genetic epidemiologist with Harris and MCG, is a co-principal investigator and receives a $ 3.4 million grant from the National Institutes of Health to examine 400 pairs of twins between the ages of 22 and 45 to find answers. .

Identical and fraternal twins will help researchers control genetics, which, coupled with environmental factors such as diet and activity level, contributes to obesity, which affects approximately 40% of US adults . Infection rates reach nearly 50% in adults in the United States. disease control and prevention centers.

Like their faces, the genetics of identical twins are identical, while fraternal twins, like many siblings, share 50% of their DNA, says Wang. Similar to the general population, about 50% of twins are now overweight and 30% are obese, investigators said about twins being followed for 15 years at the Institute of Prevention. Georgia, MCG. Especially with identical twins, their circumference tends to be similar, they note, even though they may live in very different environments. Their similarities and differences allow researchers to more easily analyze how environmental factors, rather than genetics, contribute to fat and muscle strength.

Mastering genetics in the quest for better therapeutic targets is also important because it's true that two people can go bad, but only one person pays the price of weight gain and associated health problems, Wang says. This can also help explain why some people can not control their weight and why others are "fit and fat".

Be that as it may, obesity is widely considered a "health failure," Wang points out.

"Obesity has been studied for so many years and weight loss is so difficult that we would like to find a mechanism that we could target to help people avoid diseases related to obesity," she said.

The difficulty in losing weight – and not losing it – can discourage even a hard-working individual, one of the many reasons why investigators want to know more about the role of muscle and whether the shape of our muscle can be a better indicator of our health an issue of scale.

Although muscle has not been a real target organ of intervention for these people, says Harris, it is actually a logical point of convergence. "We think it's an organ that we can really target to improve metabolic and cardiovascular health," Harris said.

Even among those who rarely exercise, skeletal muscle is one of our larger organs, literally helping to support the skeleton that keeps us standing, one of its most important functions, says Harris. Muscle also helps us to determine our metabolic homeostasis – essentially the efficiency of our body's functioning – and our sensitivity to insulin. In fact, a high muscle mass is associated with increased sensitivity to insulin, while insensitivity to insulin can result in diabetes.

Muscle consumes a lot of oxygen and is a big consumer of energy, Harris notes. One of its many health benefits is to extract glucose from our blood so that muscle cells, called mitochondria, can use it to help make ATP, the fuel cells. The benefits of high glucose consumption include reducing the risk of type 2 diabetes, a common consequence of obesity and a major risk factor for cardiovascular disease.

But for many of us, our muscle presents a fundamental problem: "It's not because you have muscle mass that it works," he says.

With obesity, for example, you can have a lot of muscle, which is necessary to help manage excess weight, but it may not be an effective muscle, says Harris about the paradox of obesity in bone health. Because, while it was once thought that loading activity automatically resulted in bone strengthening, it is now proven that obese people actually have a higher fracture rate.

Another key factor for healthy muscles is good for health through the production of small proteins called myokines, which can help do some good things like maintain metabolic homeostasis and improve internal communication in organs such as muscles to help them work well. Myokines, released when muscles contract, can also help mitigate the destructive inflammation that occurs during diseases such as obesity, diabetes, and hypertension. But there are also destructive myokines, such as IL-6, which promotes inflammation, is a disease strongly associated with cardiovascular disease.

Investigators therefore use whole-body vibration, where standing on a vibrating platform encourages the muscles to contract, to evaluate the myokine mix produced by each participant in the study to provide a snapshot of their muscle health without real muscle biopsy. One of the known effects of poor environmental factors is the decrease in the function of important muscle cells; researchers are therefore using near-infrared spectroscopy to also non-invasively examine their use and oxygen function.

The twins also have their independent movement monitored for seven days and keep a diet journal for three days. Blood pressure and grip strength are measured as well as fasting lipid, cholesterol and insulin levels. Participants will be asked about the use of drugs and alcohol, including smoking.

The blood flow in the brachial artery, the largest blood vessel in the upper arm, is also measured as an indicator of blood pressure.

The twins are again experiencing their psychosocial stress, due to factors such as discrimination and family dysfunction, and this time, due to the current age of the twin cohort, investigators have added questions about the neighborhood's dangerousness and violence against family and friends. to determine the impact of past and current stressors.

Few studies have been conducted on myokines in humans. But myokines are known to have a short half-life, which explains why regular efforts to increase muscle contraction may be helpful. In fact, MCG investigators have evidence that a single session of whole-body vibration actually begins to improve the mix, so that they look at the direct response of myokines to whole body vibrations.

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