Calf circumference as a surrogate indicator for detecting low muscle mass in hospitalized geriatric patients

Sarcopenia is characterized by low muscle strength, decreased muscle mass, and decline in physical performance. While the measurements of muscle strength and physical performance are easy to perform, an accurate evaluation of muscle mass is technically more demanding. We therefore evaluated the suitability of calf circumference (CC) as a clinical indicator for muscle mass.

In a cross-sectional single-centre study, geriatric inpatients were assessed for sarcopenia according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) consensus. Calf circumference was tested for correlation with appendicular skeletal muscle mass index (ASMI). Receiver operating characteristic curves (ROC) were used to calculate the discriminatory value of the CC cut-off values to differentiate patients above and below ASMI cut-offs for sarcopenia.

In this study population (n = 305, age 83.5 ± 7.0 years, BMI 25.7 kg/m², 65.6% female), the prevalence of sarcopenia was 22.6%. In subjects with low ASMI, mean CC was 29.5 ± 3.4 cm for females and 32.0 ± 3.4 cm for males. A positive relationship between CC and ASMI was found. The optimized cut-off value for CC to identify patients with low ASMI was <31.5 cm for females (sensitivity 78%, specificity 79%), and <33.5 cm for males (sensitivity 71%, specificity 62%).

In clinical settings where imaging technology for muscle mass quantification is not available, simple calf circumference measurement may be used as a dependable indicator for low muscle mass in older adults.