New Perspectives for Low Muscle Mass Quantity/Quality Assessment in Probable Sarcopenic Older Adults: An Exploratory Analysis Study

Abstract

Background: Low muscle mass quantity/quality is needed to confirm sarcopenia diagnosis; however, no validated cut-off points exist. This study aimed to determine the diagnostic accuracy of sarcopenia through muscle mass quantity/quality parameters, using the bioimpedance analysis (BIA), isokinetic, and ultrasound tools in probable sarcopenic community-dwelling older adults (≥60 years). Also, it aimed to suggest possible new cut-off points to confirm sarcopenia diagnosis.

Methods: A cross-sectional exploratory analysis study was performed with probable sarcopenic and non-sarcopenic older adults. BIA, isokinetic, and ultrasound parameters were evaluated. The protocol was registered on ClinicalTrials.gov (NCT05485402).

Results: A total of 50 individuals were included, 38 with probable sarcopenia (69.63 ± 4.14 years; 7 men and 31 women) and 12 non-sarcopenic (67.58 ± 4.54 years; 7 men and 5 women). The phase angle (cut-off: 5.10° men, p = 0.003; 4.95° women, p < 0.001), peak torque (cut-off: 66.75 Newtons-meters (N-m) men, p < 0.001; 48.35 N-m women, p < 0.001), total work (cut-off: 64.00 Joules (J) men, p = 0.007; 54.70 J women, p = 0.001), and mean power (cut-off: 87.8 Watts (W) men, p = 0.003; 48.95 W women, p = 0.008) in leg extension, as well as the the forearm muscle thickness (cut-off: 1.41 cm (cm) men, p = 0.017; 0.94 cm women, p = 0.041), had great diagnostic accuracy in both sexes.

Conclusions: The phase angle, peak torque, total work, and mean power in leg extension, as well as forearm muscle thickness, had great diagnostic accuracy in regard to sarcopenia, and the suggested cut-off points could lead to the confirmation of sarcopenia diagnosis, but more studies are needed to confirm this.

Keywords: bioelectrical impedance; isokinetic; muscle mass; older adults; sarcopenia; ultrasound.

Figure A1

Measurement of upper-leg ultrasound parameters. (a) Transducer position between the anterior super iliac spine and the proximal end of the patella at 30% proximal of the superior border of the patella. (b) Transducer position between the anterior super iliac spine and the proximal end of the patella at 50%. (c) SFT, QF, and RF parameters of probable-sarcopenic older adults at 30%. (d) SFT, QF, and RF of probable-sarcopenic older adults at 50%. (e) SFT, QF, and RF parameters of non-sarcopenic older adults at 30%. (f) SFT, QF, and RF parameters of non-sarcopenic older adults at 50%. SFT, subcutaneous fat thickness; QF-MT, quadriceps femoris muscle thickness; RF-MT, rectus femoris muscle thickness; RF-W, rectus femoris width; RF-CSA, rectus femoris cross-sectional area; RF-P, rectus femoris perimeter.

Figure A2

ROC analysis for the diagnostic accuracy of sarcopenia of BIA parameters. (a) Skeletal muscle mass (SM) in women. (b) Skeletal muscle mass index (SMI) in women. (c) Appendicular skeletal muscle mass (ASM) in women. (d) Skeletal appendicular skeletal muscle mass (ASMI) in women. ROC analysis is significant when the area under the curve (AUC) is >0.5 and the lower 95% confidence interval (CI) value is >0.5. A p-value < 0.05 is statistically significant.

Figure 1

Measurement of FA and pennation angle ultrasound parameters. (a) Transducer position at 30% proximal between the styloid process of the radius and the insertion of the biceps brachii muscle into the radial tuberosity. (b) Transducer position 30–50% between the anterior super iliac spine and the proximal end of the patella with transduce parallel to the long axis. (c) FA-MT of probable sarcopenic older adults. (d) FA-MT of non-sarcopenic older adults. (e) Upper-leg pennation angle of probable sarcopenic older adults. (f) Upper-leg pennation angle of non-sarcopenic older adults. FA-MT, forearm muscle thickness; PA, pennation angle.

Figure 2

ROC analysis for the diagnostic accuracy of sarcopenia of the phase angle by BIA and ultrasound parameters. (a) Phase angle (PhA) by BIA in men. (b) Phase angle (PhA) by BIA in women. (c) Forearm muscle thickness (FA-MT) in men. (d) Forearm muscle thickness (FA-MT) in women. (e) Pennation angle (PA) in men. BIA: bioelectrical impedance analysis. ROC analysis is significant when the area under the curve (AUC) is >0.5 and the lower 95% confidence interval (CI) value is >0.5. A p-value < 0.05 is statistically significant.

Figure 3

ROC analysis for the diagnostic accuracy of sarcopenia of isokinetic parameters. (a) Peak torque (PT) in extension at 180° s⁻¹ in men. (b) Peak torque (PT) in extension at 180° s⁻¹ in women. (c) Total work (TW) in extension at 180° s⁻¹ in men. (d) Total work (TW) in extension at 180° s⁻¹ in women. (e) Mean power (MP) in extension at 180° s⁻¹ in men. (f) Mean power (MP) in extension at 180° s⁻¹ in women. ROC analysis is significant when the area under the curve (AUC) is >0.5 and the lower 95% confidence interval (CI) value is >0.5. A p-value < 0.05 is statistically significant.

Figure 4

New perspectives for low muscle mass quantity and quality assessment to increase the accuracy of sarcopenia diagnosis in community-dwelling older adults. EWGSOP, European Working Group on Sarcopenia in Older People; HGS, handgrip strength; BIA, bioelectrical impedance analysis; PhA, phase angle; FA-MT, forearm muscle thickness; PT, peak torque; TW, total work; MP, mean power; SM, skeletal muscle mass; SMI, skeletal muscle mass index; ASM, appendicular skeletal muscle mass; ASMI, appendicular skeletal muscle mass index.