Sarcopenia, i.e., loss of muscle mass, manifests itself from the age of 40-50, but it can be reversed… To have a serene life in old age, we must learn to age well. It is often believed that we need to take action when we get old. Instead, it is when we are well that we need to seriously do something for our future well-being. In fact, among the factors that change most with age in the physical-biological sphere is muscle mass. Generally, the loss of muscle mass, in medical terms identified as sarcopenia (from the Greek sarx, flesh, and penia, deficiency), begins at age 40. From that age up to the age of 70, we lose about 8% of muscle mass every 10 years, but after the age of 70, the process accelerates, reaching up to 15% per decade, if we do not take counter-measures. Often we do not realize this phenomenon because the dimensions of our body and our limbs remain the same. But if we evaluate the muscle mass with diagnostic tools such as a CT scan¹ or a densitometry,² stagnation is obvious, with a strong growth of adipose mass (body fat). Sarcopenia is considered a key component of frailty in the elderly, besides the progressive loss of strength and stamina.

The muscular system, composed of more than 600 different muscles, alone constitutes about 40% of the entire human body, with higher percentages in the adult than in the child and the elderly, in the male than in the female, and in the athlete than in the sedentary.

Many consider the muscle as an organ exclusively responsible for managing the movement of the body, but the functions are much more than that. Other functions include determining the movement, but also the maintenance of posture, stabilization of joints, protection of bony structures and internal organs, blood circulation, breathing and digestion, even defecation. The heart is also a particular form of muscle that is affected by sarcopenia. However, the contraction of muscles, which results from their ability to convert chemical energy into active mechanical energy, also generates heat: about 45% of the energy produced is lost in the form of heat. Therefore, the muscle is an important source of thermal energy and thermoregulation: as we lose muscle mass, we often handle temperature changes worse and easily feel cold.

But skeletal muscle tissue is also considered a very important endocrine organ (i.e., capable of producing and metabolizing many hormones) that expresses and releases particular substances called cytokines (also called myokines) in the circulatory stream that can influence the body’s metabolism (in particular, that of sugars) and the inflammatory status in tissues and organs. This is why constant physical activity is important even with advancing age: it induces multiple beneficial effects on the reduction of fat mass, on the increase of lean mass, on the improvement of cardiovascular and metabolic functions in general. An active lifestyle produces the maintenance of a good health condition because it increases the production and release of myokines, involved in the regulation of glucose and lipid balance (homeostasis), in the control of the inflammatory response, in the creation of new blood vessels (angiogenesis), in the revascularization processes where there has been an interruption of blood circulation, and in the formation of new muscles (myogenesis) after inactivity. The muscles then communicate with all the other endocrine organs such as adipose tissue, bone, the liver, the pancreas, and the brain. Physical inactivity, or muscle disuse caused by disease, is, therefore, the cause of alteration, not only of muscle mass, but also of the abnormal response of many other organs and explains why physical inactivity is responsible for the increased risk of diseases such as cardiovascular and metabolic disorders, cancer, and osteoporosis. What do we need to do? It is essential to increase muscle mass by constantly practicing a balanced physical activity.

Valter Giantin

¹ Computerized tomography (CT) scan; a diagnostic tool for detecting diseases and injuries, using computer processing and rotating X-ray machines to create cross-sectional images of the body.

 ² A tool that measures body mass and volume and calculates body density