How do I know if I am losing too much muscle mass (sarcopenia)?
Concerned about muscle loss? Ask your general practitioner or specialist to measure both your muscle strength and your physical functioning. Low muscle mass alone is not enough to establish a diagnosis of sarcopenia.
Sarcopenia is the gradual loss of muscle mass and muscle strength that can occur with ageing. According to the two major international guidelines, EWGSOP2 and AWGS 2019, the diagnosis is based on three things simultaneously: too little muscle mass, too little muscle strength, and/or poor physical functioning. Low muscle mass alone is therefore not sufficient1,2.
Muscle strength is measured in practice with a hand dynamometer: you squeeze a small device as hard as you can. This measurement is only reliable when it is always performed in the same way, with the same hand, posture and number of attempts. How quickly you rise from a chair and your walking speed are also recognised measures. Muscle mass itself is measured with a DXA scan, similar to a bone density scan but focused on muscle tissue, or with bioelectrical impedance, in which a weak current passes through your body. A combination of simple movement tests, the SPPB, provides a broader picture of your physical functioning3,4.
Ultrasound imaging of muscles is being investigated as a supplementary measurement method, but it is still in its infancy. A meta-analysis showed only moderate to low diagnostic accuracy, and all 17 included studies had a high risk of bias. As a supplement it may be useful, but it is not ready to replace the standardised tests for the time being5.
How commonly sarcopenia occurs depends heavily on the setting. In people aged 60 and older in the general population, on average around 10 percent have sarcopenia. In nursing homes and hospitals that percentage rises considerably. Because no single universally accepted definition yet exists, studies are difficult to compare6.
The consequences can be serious. In dialysis patients, sarcopenia is associated with an 82 percent higher risk of death; low muscle strength alone already doubles the risk. In people with COPD, sarcopenia occurs in 15 to 34 percent and is associated with poorer lung function and lower quality of life7,8. Note that these are associations, not proven cause-and-effect relationships. If you are concerned, see your general practitioner so that the appropriate measurements can be taken.
Based on multiple guideline and review articles (PMID 38583268, 38337720, 34537916, 21624928, 36513380, 32862514, 34989172, 33786569). The diagnostic criteria come from two broad international guidelines. Most outcome studies are observational in nature. No randomised trials are available for diagnostic accuracy in this selection.