Existing and Emerging Measures of Muscle Strength and Mass in the Assessment of Sarcopenia

Abstract Background Sarcopenia, an accelerated loss of muscle strength and mass is a major driver of adverse health outcomes in older people. The European Working Group on Sarcopenia recommends muscle strength assessment with handgrip strength (HGS) or five chair stands test (5CST) and muscle mass assessment with dual energy X-ray absorptiometry or bioelectrical impedance analysis (BIA). However, these methods can be contraindicated, unavailable or patients can be unable to perform them. We sought to compare the existing measures HGS, 5CST and BIA to emerging measures: quadriceps muscle strength (QMS) and muscle ultrasound. Methods Thirty-one participants from a local healthy ageing group (mean age 71±5 years, 80% female) were recruited to the FRAILMatics Physiological Cohort. Max HGS was assessed using the Jamar Plus+ dynamometer and 5CST timed from a standard height chair. Max QMS was measured with the Actiforce hand-held dynamometer. BIA was performed with the TANITA DC-430 MAP and the Sergi equation used to estimate appendicular skeletal muscle mass (ASMM). Rectus femoris muscle thickness (RFMT), vastus lateralis muscle thickness (VLMT) and anterior thigh muscle thickness (ATMT) measurements were taken using the linear array transducer on the GE Vscan Air point of care ultrasound system. Pearson correlation was used to examine the relationship between measures. Results Strong correlation was seen between max QMS and max HGS (r = 0.73, P <0.001); moderate correlation between RFMT, VLMT, ATMT and ASMM (r = 0.51, P <0.01; r = 0.56, P<0.01; r = 0.40, P <0.05). 5CST was not correlated with any of the measures (P >0.05). Conclusion In the assessment of sarcopenia, QMS and muscle ultrasound could be alternatives to HGS and BIA respectively, especially in cases where the latter are not available or contraindicated. 5CST appears less useful in the assessment of sarcopenia and may be more appropriate as a test of physical performance.