Early Nutritional Intervention in Patients Undergoing Liver Transplantation

Feasibility of the study was assessed using a set of predefined indicators: the eligibility rate (% of patients on the waiting list who met eligibility criteria), the recruitment rate (% of eligible patients who agreed to participate), the target recruitment rate (% of participants enrolled relative to the predefined sample size), adherence to the protocol (% of participants who completed all planned data collection time points), and adherence to the intervention (% of participants who followed the nutritional intervention as intended). The attrition rate was also measured as the percentage of participants lost to follow-up or withdrawn after LT. The incidence of serious and non-serious adverse events during the study period was documented to evaluate the safety of the intervention.

The nutritional risk of participants was assessed using the Liver Disease Undernutrition Screening Tool (LDUST), which is specifically designed for patients with chronic liver disease. This tool includes six questions addressing nutritional intake, weight loss, subcutaneous fat loss, muscle mass loss, fluid accumulation, and reduced functional capacity. The LDUST has shown good correlation with dietitian assessments of malnutrition. Using the LDUST, patients were classified into one of two categories: absence or presence of malnutrition risk.

Muscle strength was assessed using the Chair Stand Test (CST), which provides a functional evaluation of muscle strength and endurance. The CST allows for a robust measure of lower limb function. Starting from a seated position, participants were asked to stand up and sit down without using their arms (the participant's arms were crossed over their chest) for a total of five times without assistance. The test was performed three times, and the average completion time was recorded. Patients unable to perform the test were assigned a score of 32 seconds. A completion time exceeding 15 seconds indicates reduced muscle strength

Muscle mass was assessed using SMI measured by CT scan, the gold standard method for quantitative evaluation of sarcopenia. The skeletal muscle area was measured in cm2 from CT by segmenting muscles at the level of the third lumbar vertebra (L3) and normalized to height in m2. The SMI at the L3 level has demonstrated a strong correlation with clinical outcomes and with total body muscle mass. A SMI of less than 38.5 cm²/m² for women and less than 52.4 cm²/m² for men were used as cut-off values to define reduced muscle mass in this study. As recommended by EWGSOP, the diagnosis of sarcopenia was based on low SMI combined with reduced muscle strength, assessed using the CST.

Quality of life was assessed using the Short Form 36 (SF-36) questionnaire, a validated and widely used tool for evaluating participants' perceptions of their quality of life. The SF-36 consists of 36 questions and covers 8 health dimensions: physical activity, limitations due to physical condition, limitations due to mental health, life and social relations, pain, vitality, mental health, and perceived health. Responses are scored from 0 to 100, with each dimension comprising 2 to 10 questions. The domain scores are further grouped into overall physical and mental health scores. Additionally, the SF-36 includes a question related to the evolution of health perceived by the patient. Higher scores reflect better quality of life.