Sarcopenia is a progressive muscular disease that is defined by three components:
- Reduced muscle mass: measurable for example by bio-impedance analysis (BIA), DXA or MRI.
- Reduced muscle strength: objectively measured by hand-grip measurement with a dynamometer or the chair-rise test.
- Reduced physical performance: measured via gait speed, Timed-Up-and-Go or the Short Physical Performance Battery (SPPB).
For the clinical diagnosis, the European working group (EWGSOP2, 2019) established a two-step procedure: first screening with hand-grip strength or the chair-rise test, and if abnormal then confirmation by means of body composition measurement.
- 60 to 70 years: 5 to 10 percent sarcopenic.
- 70 to 80 years: 10 to 20 percent.
- Over 80 years: 20 to 40 percent.
- In nursing homes: over 40 percent.
- After a hospital stay: a marked increase — often the sarcopenia only becomes manifest in hospital.
The figures have remained relatively stable over the past years, while at the same time life expectancy is rising. This means: more and more people are living ever longer with a muscular impairment that significantly affects their lives — and that would largely be modifiable.
From the age of 30, an adult loses on average 0.5 to 1 percent of muscle mass per year. From the age of 60, the loss accelerates to 1 to 2 percent per year. Muscle strength declines even faster than muscle mass — this is an important point that is often overlooked. One can have muscles rich in mass that nevertheless lose strength (dynapenia).
The consequences are not linear but stepwise. Certain threshold values mark clinically relevant transitions: from the point of losing the ability to stand up from a chair without support, the risk of falling rises sharply. Below a gait speed of 0.8 meters per second, mortality and the risk of needing care increase markedly.
A simple everyday test: If you can stand up from a normal chair five times in a row, without using the armrests, in less than 15 seconds — your muscle function is appropriate for your age. Over 15 seconds: suspicion of sarcopenia, consider a check-up with your family doctor or a geriatrician.
Sarcopenia is multifactorial. The most important drivers:
- Lack of movement: The strongest single factor. Every day in bed or in an armchair costs muscle. A person aged 80 loses up to 10 percent of their muscle mass during one week of being bedridden.
- Insufficient protein intake: The age-appropriate recommendation of 1.0 to 1.2 g per kg of body weight is not reached by most older people. During acute illness even 1.5 g per kg. More on this: malnutrition in old age.
- Chronic inflammation: So-called inflammaging — chronically elevated levels of interleukin-6, TNF-alpha and CRP — accelerates muscle loss.
- Hormonal changes: Decline of testosterone, growth hormone, IGF-1 and vitamin D.
- Neurodegeneration: Loss of motor neurons leads to functional decoupling of muscle fibers.
- Medications: Corticosteroids, certain statins (in myopathy), proton pump inhibitors (via B12 malabsorption). See also: deprescribing and polypharmacy in old age.
- Chronic diseases: heart failure, COPD, chronic kidney failure, tumor diseases, diabetes — all intensify sarcopenia.
- Hospital stay: Acute illnesses with bed rest massively accelerate muscle loss — one reason why early mobilization is so important.
→ On the overarching significance for resilience and overall prognosis: frailty syndrome.
The structured diagnostic work-up follows the EWGSOP2 algorithm:
Step 1: Screening (SARC-F questionnaire)
Five simple questions on strength, walking, standing up, climbing stairs, falls. A value of 4 points or more signals suspected sarcopenia. A frailty screening is recommended in addition.
Step 2: Strength measurement
- Hand-grip strength with a dynamometer: Men below 27 kg, women below 16 kg are abnormal.
- 5-chair-rise test: Standing up five times without using the armrests in under 15 seconds.
Step 3: Muscle mass determination
- Bio-impedance analysis (BIA): Practical in everyday use and well available.
- DXA (dual-energy X-ray absorptiometry): The gold standard, often carried out together with the bone density measurement.
- MRI: Research standard, clinically rarely necessary.
Step 4: Physical performance
- Gait speed: Below 0.8 m/s is abnormal.
- Timed-Up-and-Go: Over 13.5 seconds indicates sarcopenia.
- SPPB (Short Physical Performance Battery): Under 8 out of 12 points is pathological.
The diagnosis is confirmed when reduced strength, reduced mass and reduced physical performance are all demonstrated. The most severe form is referred to as “severe sarcopenia”. A comprehensive geriatric assessment embeds this diagnostic work-up into the overall context.
Sarcopenia is one of the few geriatric diagnoses in which non-pharmacological therapy clearly outperforms drug therapy. Two pillars are decisive:
1. Progressive strength training
This is the core of the therapy. Progressive means: the weight or resistance is increased at regular intervals because the muscle adapts. The evidence is overwhelming:
- Strength training two to three times per week for at least eight to twelve weeks
- Load: moderate to heavy (depending on the starting condition)
- Repetitions: 8 to 12 per exercise, two to three sets
- Target muscles: large leg muscles (quadriceps, hip extensors, calf muscles) and the trunk
- Result in studies: strength gains of 30 to over 100 percent — even in 85- and 90-year-olds
Important: strength training is not aerobic endurance training. Walking, cycling and swimming are good for the heart and circulation, but not sufficient for building muscle. For sarcopenia, resistance training is needed — ideally supervised, starting with one’s own body weight or light aids, then increased. In addition, a geriatric early rehabilitation can be useful, especially after hospital stays.
2. Sufficient protein intake
The critical number: 1.0 to 1.2 g of protein per kg of body weight per day for healthy older people. In illness or stress 1.2 to 1.5 g per kg. For a patient weighing 65 kg this means 65 to 80 g of protein per day — an amount that is often not reached without conscious planning. The risk of malnutrition in old age is closely linked to the development of sarcopenia.
Even more important than the total amount is the distribution: 25 to 30 g of protein per main meal are needed so that muscle protein synthesis is stimulated. A breakfast of bread with jam barely provides 5 g. A quark breakfast with nuts and berries provides 25 g.
- Protein-rich foods: quark, cottage cheese, eggs, fish, lean meat, pulses, tofu, soy products, whey powder.
- In case of insufficient intake: sip feeds or protein powder — medically sensible, not sports marketing.
3. Combination: training plus protein
The two pillars work synergistically. Protein alone without training does not lead to muscle building. Training without sufficient protein leads to fatigue without building up. Combined, the effect is multiplied.
4. Vitamin D correction in case of deficiency
In case of a proven vitamin D deficiency (below 50 nmol/l), substitution is sensible — it improves muscle strength and balance moderately. Without a deficiency, no routine use.
5. Further interventions
- Treatment of underlying diseases (heart failure, COPD, kidney failure)
- Treat depression — it intensifies muscle loss via lack of movement and loss of appetite
- Medication review for sarcopenia-promoting preparations — consider deprescribing
- Hearing aid and visual aid correction in order to enable social participation and movement
→ How malnutrition and sarcopenia are connected: malnutrition in old age.
→ On the significance of immobility during illness: immobility in old age.
Sarcopenia is rarely isolated. It is often an early sign of a more comprehensive development:
- Frailty: Sarcopenia is one of the central building blocks of frailty syndrome.
- Fall and fracture risk: Tripled risk of falling, doubled risk of fracture. Particularly feared: the femoral neck fracture in old age.
- Limited surgical outcome: More postoperative complications, longer recovery time. Relevant for the surgical risk in old age.
- Delayed convalescence after illness: Every hospital phase costs additional muscle.
- Mortality: Independent predictor of an increased 1- and 5-year risk of death.
The consequence: anyone who suddenly avoids stairs in old age, is exhausted after shopping or needs armrests when standing up should not dismiss this. It is a structural warning sign that is reversible through targeted intervention. Accompanying this, attention should also be paid to a possible osteoporosis in old age, as both diseases frequently occur together.
→ On the overall picture of frailty: frailty syndrome.
→ On fall prevention: fall prevention.
Concrete occasions:
- Increasing difficulties standing up from an armchair, climbing stairs or carrying things
- Unintended weight loss without any other explanation
- Increasing unsteadiness when walking, tendency to fall
- Rapid exhaustion during everyday activities
- Before or after a planned major procedure — particularly relevant for joint replacement in old age
- After a hospital stay with a marked loss of function
The first point of contact is the family doctor. In geriatrics, sarcopenia is part of every assessment and is treated in cooperation with physiotherapy, nutritional counseling and — if needed — neurology or endocrinology.
→ How a comprehensive geriatric assessment embeds the diagnosis of sarcopenia: geriatric assessment.
