Ultrasonographically Measured Rectus Femoris Cross-sectional Area might Predict Osteosarcopenia

Aim: We have aimed to investigate the role of ultrasonographic muscle parameters (UMP) in predicting osteosarcopenia in bedridden patients in a palliative care center. Background: The role of ultrasound has not been evaluated in predicting osteosarcopenia. Objective: Reduced muscle thickness (MT) and cross-sectional area (CSA) have often been observed in individuals with sarcopenia, reflecting muscle loss and atrophy. Meanwhile, the potential role of muscle ultrasound has not been evaluated in predicting osteosarcopenia. Methods: We have conducted a prospective, observational study between January 2021 and 2022. We have recorded the demographics, comorbidities, and nutritional status by using the mini nutritional assessment-short form. We measured handgrip strength with a hand dynamometer and the muscle mass with dual X-ray absorptiometry. Sarcopenia was defined by the European Working Group on Sarcopenia in Older People 2 criteria. Osteoporosis was diagnosed according to the World Health Organization criteria. We have categorized the body phenotypes into four groups: "non-sarcopenic non-osteoporotic," "sarcopenic alone," "osteoporotic alone," and "sarcopenic osteoporotic." We have measured the subcutaneous fat thickness (SFT), MT, and CSA of the rectus femoris (RF) and biceps brachii (BB) via ultrasonography. A multivariate regression analysis was performed and area under curve (AUC) values were used to evaluate the accuracy of UMPs. Results: We included 31 patients (mean age: 74.6 +/- 12.1 years, 54.8%: male). The prevalences of sarcopenia, osteoporosis, and sarcopenic osteoporosis were 71%, 48.4%, and 41.9%, respectively. Only the "sarcopenic osteoporotic" phenotype was negatively correlated with all UMPs. In the regression analysis, only the "sarcopenic osteoporotic" phenotype was independently associated with RFCSA (ss=-0.456, p= 0.024). The AUC for all patients was >0.700. Conclusion: RFCSA measurement might be useful in the screening for osteosarcopenia. This has been the first study investigating the relationship between UMPs and body phenotypes. Multi-center and large-scale studies are, however, needed.