Ultrasonographic evaluation of the calf muscle mass and architecture in elderly patients with and without sarcopenia

Abstract

Background/objectives: To sonographically assess the muscle mass and architecture of sarcopenic elderly subjects, and to explore the utility of ultrasound (US) measurements in predicting sarcopenia.

Methods: One hundred elderly subjects were enrolled in this cross-sectional study. Mean age value of our study population was 73.08±6.18years. The diagnosis of sarcopenia was confirmed by measuring fat-free mass index (using bioelectrical impedance analysis) and handgrip strength. Calf circumference was measured and US evaluations comprised bilateral gastrocnemius muscle (MG) thickness, fascicle length and pennate angles; subcutaneous fat and dermis thicknesses in the calf.

Results: Bilateral muscle thickness and fascicle length values were significantly lower in patients with sarcopenia (both p<0.05). Sarcopenic and nonsarcopenic subjects had similar pennate angles, subcutaneous fat and dermis thicknesses. Median thickness ratio (100×t (MG)/[t (subcutaneous tissue)+t (dermis)+t (MG)]) values were 64% (40-88%) in the right and 64% (38-86%) in the left calf. Bilateral MG thickness and fascicle length values showed high sensitivity in predicting sarcopenia (all values>76.92%).

Conclusions: Gastrocnemius muscle thickness and fascicle length values are lower in sarcopenic elderly and these two parameters can serve as alternative measurements for predicting/quantifying sarcopenia. Calf circumference measurements alone may not be appropriate for assessing sarcopenia. Instead, US imaging can conveniently be used to evaluate different compartments of the musculoskelal system in (sarcopenic) elderly.

Keywords: Architecture; Fat; Gastrocnemius; Older adult; Sarcopenia; Ultrasound.