A Look at Cytokine Storm in Muscles

During the global pandemic the cytokine storm and its tissue damaging impact via acute inflammation is front and center.

When the immune system is fighting pathogens such as the Covid virus, cytokines signal immune cells such as T-cells and macrophages to travel to the site of infection.

Scientists classified IL-6 as a proinflammatory cytokine. But new data is emerging in the world of sports science that muscle damage may not be required to provoke an increase in plasma IL-6 during exercise.

That’s because IL-6 seems to play a dual role. IL-6 is classified as a multi-functional cytokine, which can act as both a pro- and anti-inflammatory cytokine.

Myokines are a type of a chemical messenger in a class called cytokines. Many of the cytokines we already know about are the kind liberated from adipose tissue, your body fat, particularly the truncal fat mass that gives you that apple-shape.

The cytokines produced by muscle tissue, which are known as myokines (“myo” being the Latin root for muscles), have anti-inflammatory effects.

Aerobic exercise provokes a systemic cytokine response, but without triggering pro-inflammatory tumor necrosis factor alpha (TNF-alpha) to fight off an infection

Many of these are inflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha) and interleukin-1 family (IL-1), which are involved in a variety of disease states, including cancer.

Myokines also increase your insulin sensitivity by improving glucose utilization inside your muscles and, acting as chemical messengers, myokines help inhibit the release of inflammatory cytokines produced by body fat.

A burst in myokines was once believed to cause muscle damage.

But now science is discovering that IL-6 activated by exercise, may be necessary to confer some of the benefits of exercise such as improved insulin sensitivity.

Muscle is the seat of insulin sensitivity which is a key to both disease prevention and fat loss. Acute elevation of IL-6 was found to reduce postprandial blood glucose levels and insulin secretion by delaying gastric emptying in men with type 2 diabetes.

Cytokine storm is grabbling headlines. But the myokines produced in muscle tissue may also be an important cytokine, one that helps fight off the unresolved subclinical inflammation tied to chronic disease.