Bedside Ultrasound as a Potential Screening Tool for Sarcopenia
Ken Madden holds the Allan M. McGavin Chair in Geriatric Medicine at the University of British Columbia and is the editor-in-chief of the Canadian Geriatrics Journal. His lab has examined the effect of exercise interventions in older adults with Type 2 diabetes, and the impact of sedentary behaviours on cardiometabolic risk factors. He is division head of Geriatric Medicine at Vancouver General Hospital and is chair of the North American Regional Committee for the International Association of Gerontology and Geriatrics. Read the related Age and Ageing paper here.
One of the prominent effects of the aging process is a gradual decline in both muscle quantity and muscle quality. This phenomenon is referred to as sarcopenia, from the Greek terms for flesh (sarx) and loss (penia)1. This process starts after the age of about 25, is found in approximately 20% of persons over the age of 652, and increases to a prevalence of 30% in subjects over the age of 803. Sarcopenia has a devastating impact on the health and quality of life of older adults4. Meeting criteria for sarcopenia has been shown to be associated with increased mortality in older adults5 and with the development of functional disability over a 2-year period6. Sarcopenic patients are 3 times more likely to fall over 2 years7 and sarcopenia is strongly established as a risk factor for fractures8, and is also a risk factor for hospitalization9.
Despite the risk sarcopenia poses to older adults undergoing acute stressors, this condition is almost never screened for in the acute care setting. The main barrier is the fact that in all current guidelines10 there can be no diagnosis without an assessment of muscle mass using dual-energy x-ray absorptiometry (DEXA) scanning; this leads to a practical outcome in which ‘there seems to be a large cleft between guidelines and clinical practice.’11 The fact that sarcopenia can be treated through strength training and protein supplementation12 and the development of several potential therapies (such as antimyostatin antibodies)13 makes this oversight increasingly inappropriate. One possible solution would be the use of Point of Care Ultrasound (PoCUS) (increasingly referred to as the “Stethoscope of the 21st century”14) as a quick bedside screen for this condition.
In our study, we recruited 150 older adults (age >= 65; mean age 80.0±0.5 years, 66 women, 84 men) from outpatient geriatric medicine clinics at an academic centre (Vancouver General Hospital, Vancouver, Canada). Each subject had lean body mass (by bioimpedance assay), grip strength, and mid-arm biceps circumference measured. Using point-of-care ultrasound, we measured muscle thickness (vastus medialis), a procedure that takes approximately 2 minutes. In our cross-sectional study, we were able to show strong associations between PoCUS measures of muscle thickness and all measures of muscle mass (both total lean body mass and biceps circumference). Even more interestingly, we also were able to show a strong positive association between muscle thickness and grip strength, indicating that our screening measure was also strongly associated with muscle quality. Although we were able to show strong correlations between muscle thickness and both muscle quantity and muscle quality, we were not able to show any association with performance-based measures, such as gait speed.
Although much more work needs to be done to demonstrate the use of measures to screen for sarcopenia, our study suggests that point-of-care ultrasound could have utility as a rapid screening tool for this neglected condition. Rapid screening methods for sarcopenia could also help facilitate future randomized controlled trials of potential pharmacological therapies for sarcopenia, potentially improving quality of life for many vulnerable older adults.
2. Reiss J, Iglseder B, Alzner R, et al. Consequences of applying the new EWGSOP2 guideline instead of the former EWGSOP guideline for sarcopenia case finding in older patients. Age Ageing [Internet] 2019;Available from: http://dx.doi.org/10.1093/ageing/afz035
3. Morley JE, Baumgartner RN, Roubenoff R, Mayer J, Sreekumaran Nair K. Sarcopenia [Internet]. Journal of Laboratory and Clinical Medicine. 2001;137(4):231–43. Available from: http://dx.doi.org/10.1067/mlc.2001.113504
4. Wu T, Liaw C, Chen F, Kuo K, Chie W, Yang R. SARCOPENIA SCREENED WITH SARC-F QUESTIONNAIRE IS ASSOCIATED WITH QUALITY OF LIFE AND MORTALITY [Internet]. Innovation in Aging. 2017;1(suppl_1):1014–1014. Available from: http://dx.doi.org/10.1093/geroni/igx004.3682
9. Guralnik JM, Ferrucci L, Pieper CF, et al. Lower Extremity Function and Subsequent Disability: Consistency Across Studies, Predictive Models, and Value of Gait Speed Alone Compared With the Short Physical Performance Battery [Internet]. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 2000;55(4):M221–31. Available from: http://dx.doi.org/10.1093/gerona/55.4.m221
13. Camporez J-PG, Petersen MC, Abudukadier A, et al. Anti-myostatin antibody increases muscle mass and strength and improves insulin sensitivity in old mice. Proc Natl Acad Sci U S A 2016;113(8):2212–7.