Morphofunctional Assessment of Malnutrition and Sarcopenia Using Nutritional Ultrasonography in Patients Undergoing Maintenance Hemodialysis

Abstract

Background and Objectives: Malnutrition and sarcopenia are highly prevalent and clinically impactful conditions in patients undergoing maintenance hemodialysis (MHD), yet their early detection remains challenging. This study aimed to assess the diagnostic performance of nutritional ultrasonography (NUS) in the morphofunctional evaluation of malnutrition and sarcopenia, and to compare its utility with established tools such as bioimpedance analysis (BIA), biochemical markers, handgrip strength (HGS), and functional performance tests. Materials and Methods: A cross-sectional study was conducted in 74 stable MHD patients. Clinical, analytical, anthropometric, BIA, NUS, and functional parameters were collected, along with validated nutritional and frailty scales. NUS was used to assess the quadriceps rectus femoris (QRF) and preperitoneal visceral fat (PPVF), measuring Y-axis, Y-axis/height, cross-sectional muscle area rectus femoris (CS-MARF), muscle area rectus femoris index adjusted to height (MARFI_h), and supramuscular fat (SMF). Sarcopenia was defined according to the 2019 European Working Group on Sarcopenia in Older People (EWGSOP) criteria. Results: The prevalence of risk, confirmed, and severe sarcopenia was 24.3%, 40.5%, and 20.3%, respectively. Severe-to-moderate protein-energy wasting (PEW) affected 44.6% of patients. Compared to non-sarcopenic individuals, sarcopenic patients had lower values of HGS, prealbumin, lean body mass, and phase angle. NUS-derived cut-off values for sarcopenia were Y-axis ≤ 8 mm, Y-axis/height ≤ 2.9 mm/m², CS-MARF ≤ 2.4 cm², and MARFIh ≤ 0.9 cm²/m². The most discriminative NUS parameters were Y-axis and SMF (AUC 0.67), followed by Y-axis/height (AUC 0.65) and MARFI_h (AUC 0.63). NUS measurements correlated significantly with ASMI, phase angle, HGS, and SPPB scores. Conclusions: Nutritional ultrasonography is a feasible, reproducible, and clinically valuable tool for assessing muscle mass and quality in MHD patients. Its incorporation into routine practice may enhance early detection of malnutrition and sarcopenia, thereby facilitating timely, individualized nutritional interventions.

Keywords: hemodialysis; malnutrition; morphofuntional assessment; nutritional ultrasonography; sarcopenia.

Figure 1

Systematic nutritional ultrasound study of the anterior quadriceps rectus femoris (QRF) muscle. The patient was in the supine decubitus position with the headrest at 0° with both legs extended and relaxed. An imaginary line was drawn between the anterosuperior iliac crest and the upper edge of the patella (A), and the transducer was placed in a transverse position to the axis of the leg in the lower third to measure the cross-sectional area of the anterior QRF (B). The QRF muscle and its ultrasonographic measurements (C,D). CS-MARF: cross-sectional muscle area of the rectus femoris; SMF: supramuscular fat.

Figure 2

Systematic study (A,B) and ultrasound anatomy of preperitoneal visceral fat (PPVF) (C). SSCF: superficial subcutaneous fat; DSCF: deep subcutaneous fat; RAM: rectus abdominis muscle.

Figure 3

Predictive ability of nutritional ultrasound measurements of the cross-sectional muscle area of the rectus femoris (Y-axis (A); Y-axis (height) (B); MARFI (height) (C); and SMF (D)) for the diagnosis of sarcopenia according to EWGSOP2 consensus. Y-axis (height): Y-axis adjusted to height; MARFI: muscle area of the rectus femoris index adjusted to height; SMF: supramuscular fat; AUC: area under curve.

Figure 4

Correlation analysis of the values obtained by NUS (rectus femoris muscle mass and preperitoneal fat) with BIA parameters. ASMI: appendicular skeletal mass index; BFM: body fat mass; SMF: supramuscular fat; PPVF: preperitoneal visceral fat; TBW: total body water; FFM: fat-free mass.