Sarcopenia
All the information about the causes, symptoms, and possible complications of the loss of muscle mass, strength, and function.
Symptoms and Causes
Sarcopenia is the loss of muscle mass, strength, and function. Although it is mainly associated with aging, it can also be caused by physical inactivity, metabolic diseases, hormonal disorders, inadequate nutrition, or chronic musculoskeletal diseases.
It commonly appears along with significant weight loss and interferes with the ability to perform daily activities.
Depending on its presentation, there are two types of sarcopenia:
- Acute sarcopenia: muscle insufficiency appears suddenly as a consequence of injury or prolonged immobility (for example, hospitalization) and lasts less than six months. Muscle strength usually recovers with treatment and exercise once the underlying cause resolves.
- Chronic sarcopenia: muscle mass gradually decreases over time without showing evident symptoms, so diagnosis often occurs in advanced stages.
Sarcopenia is associated with physical frailty, one of the main causes of disability, making early diagnosis essential to slow its progression. Treatments focus on alleviating symptoms and improving patients’ quality of life, as there is currently no definitive cure for this condition.
Symptoms
Symptoms of sarcopenia vary among patients. The most common include:
- Muscle weakness: loss of strength affects physical capacity, making everyday tasks such as standing up, lifting objects, or climbing stairs difficult.
- Lack of balance and coordination.
- Increased risk of fractures and falls.
- Slowness of movement.
- Fatigue.
- Physical dependence, as assistance is needed to perform basic activities.
- Decreased bone density.
- Weight loss.
Causes
Sarcopenia can be of two types depending on its underlying causes:
- Primary sarcopenia: the natural aging of the body. In these cases, hormonal changes—such as decreased testosterone, estradiol, or growth hormone—play a major role.
- Secondary sarcopenia: caused by factors other than aging, including:
- Prolonged inactivity.
- Sedentary lifestyle.
- Malnutrition: deficiency of proteins, calories, or micronutrients.
- Endocrine dysfunctions, such as insulin resistance.
- Osteoporosis.
- Arthrosis.
- Osteoarthritis.
- Mitochondrial disorders: cells fail to produce enough energy, leading to tissue deterioration.
- Genetic predisposition.
Risk Factors
The main risk factors for sarcopenia include:
- Advanced age: this disease primarily affects the elderly, especially those over 80 years of age.
- Low physical activity.
- Malnutrition.
- Chronic inflammatory diseases.
- Ongoing neoplastic processes.
Complications
Sarcopenia negatively affects overall health and may lead to:
- Bone injuries and fractures as a result of falls.
- Functional disability.
- Increased mortality in older adults.
- Dependence in basic and self-care activities.
- Worsening of coexisting chronic diseases.
- Type 2 diabetes.
- Cardiovascular diseases.
- Anxiety.
- Depression.
Prevention
The best way to prevent sarcopenia is to maintain a healthy lifestyle. Recommendations include:
- Proper nutrition: a Mediterranean diet with additional protein intake provides essential nutrients for older adults.
- Daily physical activity: even moderate-intensity exercises should be performed every day. Special attention should be given to the following training types:
- Strength: using elastic bands or weights.
- Aerobic exercise: walking, swimming, dancing.
- Balance: walking in a straight line, standing on one leg, standing up without using hands.
- Flexibility: yoga, tai chi.
Which Specialist Treats Sarcopenia?
Sarcopenia is treated by specialists in Geriatrics and Rheumatology. It is also diagnosed and managed by Internal Medicine and Endocrinology and nutrition professionals.
Diagnosis
To diagnose sarcopenia, the following aspects are evaluated:
- Muscle strength: measured in both upper and lower limbs. Grip strength is commonly assessed with a dynamometer, along with weight-lifting or leg-extension tests.
- Muscle quantity: several tests are performed to measure muscle mass:
- Dual-energy X-ray absorptiometry (DEXA): uses X-rays of two energy levels to measure bone density and calcium content.
- Bioelectrical impedance analysis (BIA): measures tissue resistance to electrical current (impedance). Healthy muscles conduct electricity well, showing low impedance.
- Magnetic Resonance Imaging (MRI): the images provided by MRI allow visualization of existing muscle tissue and detection of fat infiltration in the muscles, which is a sign of weakness.
- Physical performance: functional capacity is evaluated through specific tests:
- Walking test: measures the distance the patient can walk on a flat surface in six minutes.
- Berg Balance Scale: the patient performs 14 tasks (standing up, remaining standing, sitting, etc.), and the specialist rates performance from 0 to 4. Scores range from 0 (severe impairment) to 56 (excellent).
- Timed Up and Go (TUG) test: measures the time it takes for the patient to stand up, walk three meters, return, and sit again without using armrests.
- Anthropometric indices: body characteristics that help diagnose sarcopenia include:
- Body Mass Index (BMI): the relationship between height and body mass.
- Calf circumference: the circumference of the thickest part of the calf indicates nutritional deficiency (less than 31 cm in women and less than 32 cm in men).
Treatment
Treatment for sarcopenia aims to slow disease progression, alleviate symptoms, and improve patients’ quality of life. The most effective therapies include:
- Adequate and balanced nutrition.
- Specialized nutritional intervention for patients with nutritional deficiencies or chronic diseases.
- Moderate daily exercise.
- Vitamin D and calcium supplementation.
- Hormone therapy to increase muscle mass and strength (testosterone, IGF-1, FGF-21).
- Myostatin inhibitors, which help increase muscle mass.
