What is sarcopenia and why is muscle mass crucial for health?
Sarcopenia is a condition characterized by the gradual loss of muscle mass, strength, and function. It is part of biological aging but can also be influenced by lifestyle, disease, and nutritional status. The condition not only leads to reduced physical performance but is also linked to an increased risk of falls, fractures, and a reduced quality of life.
Muscles play a central role in the body's metabolism, movement, and stability. When muscle mass decreases, both strength and balance are affected, making everyday activities progressively more difficult to perform.
What happens in the body with sarcopenia?
Sarcopenia is a complex condition that occurs through several interacting biological processes that affect the structure and function of muscle tissue.
Reduced protein synthesis: With age, the body's ability to build muscle protein decreases, while its breakdown often increases.
Hormonal changes: Levels of anabolic hormones such as Testosterone and Estradiol, as well as growth hormone and IGF-1, decrease, which contributes to reduced muscle building.
Neuromuscular changes: The number of motor neurons decreases, which impairs communication between the nervous system and muscles.
Inflammation: Low-grade chronic inflammation ("inflammaging") affects muscle function and recovery negatively.
How common is sarcopenia?
Sarcopenia is a common condition, especially in the elderly. Epidemiological studies show that:
Up to 5–10% of people over 60 years of age meet criteria for sarcopenia.
The prevalence increases to 30% or more in people over 80 years of age.
However, the condition can also occur earlier in life, especially in cases of physical inactivity, chronic diseases or malnutrition.
Symptoms – how is muscle wasting noticeable?
Sarcopenia often develops gradually and symptoms may initially be subtle.
Reduced strength: Difficulty getting up from a chair, carrying heavy objects or climbing stairs.
Reduced muscle mass: Visible loss of muscle volume, especially in the arms and legs.
Poor balance: Increased risk of falls and instability when walking.
Fatigue: Reduced endurance and faster fatigue during physical activity activity.
How is sarcopenia diagnosed?
The diagnosis of sarcopenia is based on a combination of reduced muscle strength, reduced muscle mass, and impaired physical function.
Strength: Often measured with hand grip strength or functional tests such as rising from a chair.
Muscle mass: Can be assessed using methods such as bioimpedance or advanced imaging. An established method is DEXA (dual-energy X-ray absorptiometry), which is mainly used for bone density measurement but can also analyze body composition.
Physical function: Walking speed or other functional tests are used to assess the impact on mobility.
The diagnosis is often made according to international guidelines, primarily EWGSOP2 (European Working Group on Sarcopenia in Older People).
The diagnosis is made in three steps:
1. Probable sarcopenia: Identified by reduced muscle strength, for example through low hand grip strength or difficulty getting up from a chair.
2. Confirmed sarcopenia: The diagnosis is strengthened by also demonstrating reduced muscle mass, for example via bioimpedance, DEXA or imaging.
3. Severe sarcopenia: Present when both strength and muscle mass are reduced in combination with impaired physical function, for example low walking speed.
This step-by-step model makes it possible to identify the condition early and take measures before more pronounced functional impairment occurs.
Sarcopenia often occurs together with osteoporosis, a condition sometimes referred to as osteosarcopenia. The combination entails an increased risk of falls and fractures and underlines the importance of assessing both muscle mass and bone density.
How can you prevent and treat sarcopenia?
Sarcopenia is highly treatable, especially in the early stages. With the right combination of exercise, diet and identification of underlying causes, the progression can be slowed and sometimes improved.
Strength training: Regular resistance training is the most effective measure to stimulate muscle protein synthesis and improve both strength and function. Training should be progressive, meaning that the load is gradually increased over time. Even 2–3 sessions per week can produce clear effects, especially if large muscle groups are activated through exercises such as squats, deadlifts or presses.
Protein intake: An adequate intake of protein is crucial for muscle building, especially in the elderly where the anabolic response is impaired. For many, this means a need for a higher protein intake than before, distributed evenly across the day's meals. High-quality protein, such as from animal sources or complete vegetable alternatives, is particularly important for optimizing muscle protein synthesis.
Identify underlying causes: If sarcopenia is suspected, it may be valuable to evaluate hormonal and nutritional factors that affect muscle mass. Low levels of anabolic hormones, lack of essential vitamins and minerals or signs of chronic inflammation can contribute to the development.
Low levels of Testosterone can contribute to reduced muscle mass and strength, especially in men.
Estradiol also has an impact on muscle and skeletal metabolism, not least in women.
Deficiency of Vitamin D is common and is linked to impaired muscle function and increased risk of falls.
Low iron stores, measured as Ferritin, can affect energy, endurance and physical performance.
Vitamin B12 is important for nerve function and the interaction of muscles with the nervous system.
By identifying and addressing such factors better conditions are created for training and recovery. A combination of physical activity, adequate nutrition and targeted medical assessment is crucial for preventing and treating sarcopenia and for optimizing the body's ability to build muscle.