History and exam
Key diagnostic factors
common
presence of risk factors
Age ≥65 years, low BMI, sedentary lifestyle, low protein intake, and a history of falls are risk factors for sarcopenia.
low hand grip strength
Low muscle strength (measured by hand grip test or sit-stand [chair raise] test) is considered the primary parameter of sarcopenia.[1] Low muscle strength alone can be enough to diagnose probable sarcopenia. The presence of low muscle quantity or quality (measured by imaging) confirms the diagnosis.[1]
The threshold used by the European Working Group for Sarcopenia in Older People 2 (EWGSOP2) for low hand grip strength is <27 kg for men and <16 kg for women.[1] The Asian Working Group for Sarcopenia (AWGS) defines low hand grip strength as <28 kg for men and <18 kg for women.[6]
difficulty rising from chair
Low muscle strength (measured by hand grip test or sit-stand [chair rise] test) is considered the primary parameter of sarcopenia.[1] Low muscle strength alone can be enough to diagnose probable sarcopenia. The presence of low muscle quantity or quality (measured by imaging) confirms the diagnosis.[1]
Difficulty rising from a chair may be reported by the patient, for example as part of the SARC-F questionnaire. It can also be measured objectively with the sit-stand test, which measures the amount of time needed for a patient to rise five times from a seated position without using their arms. A cut-off of >15 seconds for 5 rises indicates low strength, according to the European Working Group for Sarcopenia in Older People 2 (EWGSOP2).[1] The Asian Working Group for Sarcopenia (AWGS) uses a cut-off of ≥12 seconds for 5 rises to indicate low strength.[6]
difficulty climbing stairs
Difficulty climbing stairs may be reported by the patient, for example as part of the SARC-F questionnaire. This is associated with functional capacity impairment and activity limitation (odds ratio 6.58).[51]
slow gait
Gait speed is a commonly used index to evaluate mobility and muscle function. It is considered a fast, safe, and reliable examination method for evaluating gait. It involves having the patient walk a short distance (3-6 m), selecting the segment of stabilised speed within the distance, and calculating the average step speed in metres per second.[39]
Values <1 m/second are considered low.[2][6] Values <0.8 m/second are often used as the level to initiate screening.[40] A single cut-off speed of ≤0.8 m/second indicates severe sarcopenia.[1]
emaciation
Look for excessive emaciation or adiposity. Even with obesity, some people have a relative loss of muscle mass.[24] Use objective anthropometric measurements, with a BMI <22 kg/m² or >29 kg/m² considered outside of the normal range.
History of weight loss and low BMI is associated with high risk of sarcopenia (odds ratio 3.98).[22]
difficulty performing activities of daily living
Ask about difficulty in performing activities of daily living (e.g., shopping for groceries, cleaning) as part of the history taking. This is associated with functional capacity impairment and isometric strength that decreases at a rate of 1% to 2% per year.[52]
Other diagnostic factors
common
presence of comorbidities affecting muscle mass and/or function
Obtained from medical history associated with sarcopenia. This includes history of chronic obstructive pulmonary disease, chronic heart disease, chronic kidney disease, and Parkinson's disease and other neurological disease.
Risk factors
strong
age ≥65 years
Sarcopenia is typically a condition of older people. One US study found sarcopenia to be common in adults over 65 years of age (22.6% in women and 26.8% in men) and the prevalence to increase with age (31.0% in women and 52.9% in men in a subgroup aged 80 years or older).[4] Another study found that the prevalence of sarcopenia increased from 4% of men and 3% of women aged 70-75 to 16% of men and 13% of women aged 85 and older in a study of 694 men and 1006 women aged over 55.[5] Screen for sarcopenia in adults aged 65 years and older annually or after a major health event (such as a fall).[2]
low or high body mass index (BMI)
BMI is an anthropometric measurement based on weight (kg) over height (m) squared (kg/m²). It is used to diagnose sarcopenic obesity as it is an easy-to-perform estimation of adiposity as well as of cardiovascular risk. By the World Health Organization definition, any value ≥30 kg/m² is diagnostic of obesity and a BMI of below 18.5 is considered underweight.[20] Note that different cut-offs are used for Asian patients.[21]
History of weight loss and low BMI is associated with high risk of sarcopenia (odds ratio 3.98).[22]
sedentary lifestyle
Insufficient physical activity is a risk factor for sarcopenia.[9] Physical activity is the primary management strategy for increasing muscle mass and strength, and improving gait speed.[5]
Consider if the patient has had an extended period of bed rest. One study has found that 10 days of bed rest decreases lower limb muscle strength by 14%.[23]
low protein intake
Insufficient protein intake can lead to loss of lean body mass, increasing the risk of sarcopenia.[11] Protein intake may need to be at levels higher than the current recommended dietary allowance (RDA) of 0.8 g/kg/day to maintain muscle health in a person at risk of sarcopenia.[12]
Look for excessive emaciation or adiposity. Even with obesity, some people have a relative loss of muscle mass.[24]
History of weight loss and low BMI is associated with high risk of sarcopenia (odds ratio 3.98).[22]
falls
Falls can increase sedentary behaviour and fear of movement, increasing the loss of muscle mass and strength.[13]
weak
smoking
A meta-analysis of 12 studies (22,515 patients) found that cigarette smoking as an isolated factor may contribute to the development of sarcopenia.[14] However, the results of individual studies were largely inconsistent due to differing methods for measuring the main variables.
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