What is sarcopenia
Sarcopenia is a condition characterised by gradual muscle loss, leading to a continuous reduction in the patient’s ability to move and carry out everyday activities. It can also lead to disability and the loss of self-sufficiency, as well as an increase in the risk of falling and of bone fractures or lesions.
Although sarcopenia generally affects the elderly, it can also be developed by younger adults. Sarcopenia begins to appear around the age of 30, leading to a 3-5% loss of muscle mass by the age of 50, and a further 1-2% every year from then on. For approximately 40% of subjects, it leads to the halving of muscle mass by the age of 75, with men slightly more affected than women.
Causes of sarcopenia
In some individuals, a single, clear cause of sarcopenia can be identified, while in other cases it is not possible to identify a single isolated cause. Therefore, sarcopenia can be subdivided into two main categories:
- Primary sarcopenia (or age-related) when there is no other evident cause other than ageing itself.
- Secondary sarcopenia when there are one or more evident causes.
Often, the elderly suffer from malnutrition (either because they follow monotonous diets or because they have difficulty chewing) which can have a significant effect on the evolution of sarcopenia.
Categories of sarcopenia by cause
Age-related sarcopenia: no other evident cause other than ageing itself
Activity related sarcopenia: can be caused by bed rest, a sedentary lifestyle and immobility
Illness-related sarcopenia: associated with advanced organ deficiency (heart, lungs, liver, kidneys, brain), inflammatory diseases, malign tumours or endocrine diseases.
Nutrition-related sarcopenia: resulting from an insufficient supply of energy and/or protein, as in the case of malabsorption, gastro-intestinal conditions or the use of medicines that cause anorexia.
Symptoms of sarcopenia
Sarcopenia causes a constant feeling of weakness, loss of stamina, poor balance and a tendency to fall, slow movement and difficulty in carrying out simple everyday activities. All these factors have a significant effect on the quality of life for the elderly, reducing autonomy.
Sarcopenia is present in other symptoms associated with prominent muscular atrophy, such as:
- Cachexia: recognised among the elderly as a serious form of wasting that accompanies conditions such as cancer, congestive cardiomyopathy and terminal kidney disease. Cachexia has been defined as a complex metabolic syndrome associated with an underlying illness and is characterised by a loss of muscle mass with or without a similar loss of fat mass. The majority of individuals with cachexia also suffer from sarcopenia, but the majority of sarcopenia sufferers are not considered to have cachexia.
- Fragility: a geriatric syndrome stemming from age-related cumulative decline of various physiological systems, with a reduction in homeostatic reserve and in the ability of the organism to resist stress, thus increasing vulnerability to harmful events such as falls, hospitalisation, institutionalisation and mortality. Fragility and sarcopenia overlap. The majority of frail elderly people shows signs of sarcopenia and a number of elderly people with sarcopenia are frail. However, the general concept of frailty goes beyond physical factors and also includes psychological and social aspects, including cognitive state, social support and other environmental factors.
- Sarcopenic obesity: in conditions such as malign neoplasms, rheumatoid arthritis and ageing, lean body mass is lost while fat mass may be preserved or even increased. This state is known as sarcopenic obesity, and therefore the relationship between the loss of muscle mass due to age and strength is often independent of body mass.
Consequences of sarcopenia
Sarcopenia has serious repercussions on motor skills and on the level of physical activity for sufferers. In more serious cases it compromises autonomy in movement, balance becomes unstable, sufferers are unable to climb or descend stairs, lift object, get up from a sitting position or carry shopping home. Walking speed is seriously reduced.
In the elderly, it increases the risk of falling and related fractures, representing the main cause of invalidity and weakness.
Sarcopenia contributes to a reduction in energy consumption at rest and peripheral insulin sensitivity, facilitating the accumulation of subcutaneous and visceral fat.
Sarcopenia also has a significant effect on bone ageing, favouring the onset of osteoporosis in old age. The reduction in muscle mass in the elderly also has an effect on the body’s ability to thermoregulate, rendering subject less able to adapt to variations in environmental temperature.
How to diagnose sarcopenia
In cases of suspected sarcopenia, it is recommended to contact a general practitioner or specialist, in order to have a diagnosis as soon as possible and limit both the loss of muscular function and the possible consequences in terms of reduced autonomy and an increase in the risk of falls, with the consequent risk of hospitalisation.
The various stages of sarcopenia, which reflect the seriousness of the condition, can help to guide clinical management. EWGSOP indicates three main stages: ‘presarcopenia’, ‘sarcopenia’ and ‘severe sarcopenia’.
The stage of ‘presarcopenia’ is characterised by low muscle mass without any impact on muscle strength or physical performance. This stage can only be identified through techniques that accurately measure muscle mass in reference to the standard population.
The stage of ‘sarcopenia’ is characterised by low muscle mass, reduced muscle strength or reduced physical performance.
‘Severe sarcopenia’ is the stage in which all three criteria for definition are satisfied (reduced muscle mass, reduced muscle strength and reduced physical performance).
Assessment of sarcopenia, which must always be carried out by a specialist, can be carried out easily with the administration of a specific test recommended by EWGSOP, the SARC-F questionnaire. The test provides a rating on a scale of 0 to 10 and assesses 5 aspects of sarcopenia. The answers are based on the perception of the patient according to:
- their strength limits
- assistance in walking
- getting up from a chair
- climbing stairs
- experience with falling.
The result of the test may indicate sarcopenia and will allow the doctor to assess and recommend the best therapy for limiting the loss of muscle function.
How to prevent and treat sarcopenia
With the emergence of doubts over a person’s muscle function or a sensation of weakness that hinders normal every day activities, it is opportune to contact a general practitioner or a specialist for an assessment of their condition and, if necessary, limit the loss of muscle function.
Prevention of sarcopenia is based fundamentally on two approaches which, when combined, optimise the increase of muscle mass and function:
- Nutritional intervention, through a process of balanced nutritional education, with particular attention to a suitable supply of protein
- Maintenance of muscle activity through physical exercise
In the event that natural nourishment is not sufficient, it is necessary to contact one’s nutritionist, who will be able to recommend the most suitable treatment, with oral nutritional supplements providing high essential amino acid support.
CRUZ-JENTOFT, Alfonso J., et al. Sarcopenia: European consensus on definition and diagnosisReport of the European Working Group on Sarcopenia in Older PeopleA. J. Cruz-Gentoft et al. Age and ageing, 2010, 39.4: 412-423.
CRUZ-JENTOFT, Alfonso J., et al. Sarcopenia: revised European consensus on definition and diagnosis. Age and ageing, 2019, 48.1: 16-31.