The Quantitative Ultrasound Assessment of Lean and Intramuscular Adipose Tissue in Veterans With Chronic Kidney Disease

The accelerated muscle wasting associated with chronic kidney disease (CKD) is a source of morbidity and an increased incidence of bone fracture secondary to falls. However, sarcopenia secondary to CKD is not routinely screened or assessed in this patient population. This protocol, "Quantitative Ultrasound Assessment of Lean and Intramuscular Adipose Tissue in Veterans Project" (i.e., QUALITY VETS) is a VA Center for Innovation (VACI) funded pilot study with the purpose of using a clinically viable sarcopenia screening approach for Veterans with CKD who are currently receiving care at the Renal Service.

The investigative team will screen and assess diminished muscle mass, quality, and performance in Veterans with CKD (Stage 3 and 4), and also examine the relationship between the muscle characteristics and estimated fall risk within the sample. Key outcome measures will be obtained within the domains of muscle performance (peak grip strength), functional status (Short Physical Performance Battery), estimates of tissue/body composition (diagnostic ultrasound and DXA), and fall risk (Timed Up-and-Go test). Secondary measures will include questionnaires regarding of fall avoidance, physical activity, depression, and quality of life (QoL).

The general analysis approach will be to characterize the proportion of participants with: sarcopenia based on the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm, low muscle quality based on preliminary echogenicity cut off values and criterion strength values, and an elevated risk of falling based on the Timed Up-and-Go age-dependent cut off values. Investigators will determine the magnitude of association between the skeletal muscle outcomes and fall risk within the participant sample. Hazard ratios will be used to estimate the impact of the sarcopenia classification and echogenicity values on the positive classification of fall risk.

The optimal treatment of Veterans with CKD who have an elevated risk of falls may be enhanced by the timely identification of accelerated muscle changes. The QUALITY-VETS Project will help to determine appropriate screening and assessment strategies that could be implemented in subsequent longitudinal studies involving exercise interventions and fall prevention training.