Evaluation of Protein Distribution Optimization With Exercise Regimen on Nutritional Status, Body Composition and Functional Status in Patients Awaiting Liver Transplantation: The POWER-LT Randomized Clinical Trial

Changes in Global Leadership Initiative on Malnutrition (GLIM)-defined malnutrition

时间窗: Baseline, 12 weeks

Malnutrition will be diagnosed using the Global Leadership Initiative on Malnutrition (GLIM) criteria. Diagnosis requires at least 1 phenotypic criterion and 1 etiologic criterion. Phenotypic criteria include: a. Non-votional weight loss (%): \> 5% within past 6 months or \> 10% beyond 6 months, b. Low body mass index (BMI, kg/m\^2): \< 20 kg/m\^2 if \< 70 years or \< 22 kg/m\^2 if \> 70 years, c. Reduced muscle mass, assessed by validated body composition measuring techniques \[e.g. Dual-Energy X-ray Absorptiometry (DEXA), Bioelectrical Impedance Analysis (BIA) or Computed Tomography (CT)\]. Etiologic criteria include: a. Reduced food intake or assimillation: ≤ 50% of energy requirements \> 1 week or any reduction for \> 2 weeks or any chronic gastrointestinal condition that adversely impacts food assimilation or absorption, b. Inflammation: acute disease/injury or chronic disease-related.

Changes in Computed Tomography (CT)-derived muscle mass

时间窗: Baseline, 12 weeks

Muscle mass will be assessed using the Skeletal Muscle Index (SMI, cm\^2/m\^2). SMI will be calculated by measuring the total cross-sectional area of skeletal muscles, from a single cross-sectional Computed Tomography (CT) image at L3 vertebral level, using Hounsfield Units of -29 to +150 HU, and normalizing to height squared (m\^2).Thresholds for reduced SMI will be considered \< 50 cm\^2/m\^2 for men and \< 39 cm\^2/m\^2 for women.

Changes in handgrip strength (kg)

时间窗: Baseline, 12 weeks

Handgrip strength (kg) will be assessed using a digital handgrip dynamometer. Thresholds for reduced muscle strength will be considered \< 27 kg for men and \< 16 kg for women.

Changes in Short Physical Performance Battery (SPPB) score

时间窗: Baseline, 12 weeks

The Short Physical Performance Battery (SPPB) includes 3 components: 3-positions balance testing (sec) (0-4 points), 4-meter gait speed test (sec) (0-4 points) and 5-times chair stand test (sec) (0-4 points), with a total score of 0-12. Higher scores indicate a better physical performance: 0-3 points for worst physical performance, 4-9 points for reduced physical performance and 10-12 points for best physical performance.

Changes in Liver Frailty Index

时间窗: Baseline, 12 weeks

The Liver Frailty Index includes 3 components: handgrip strength (kg), 5-times chair stand test (sec) and 3-positions balance testing (sec). Higher scores indicate a greater degree of frailty.

Changes in European Working Group on Sarcopenia in Older People 2 (EWGSOP2)-derived sarcopenia

时间窗: Baseline, 12 weeks

Sarcopenia will be diagnosed using the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria. Diagnosis requires low muscle strength and low muscle mass. Reduced muscle strength will be diagnozed by: a. Low handgrip strength (kg): \> 27 kg for men and \> 16 kg for women or b. Low chair stand test (sec): \>15 sec for 5-times chair stand test. Reduced muscle mass will be diagnozed by: a. Low Appendicular Skeletal Muscle Mass (ASM, kg): \< 20 kg for men and \< 15 kg for women or b. Low Appendicular Skeletal Muscle Mass Index (ASMI, kg/m\^2): \<7.0 kg/m\^2 for men and \< 5.5 kg/m\^2 for women.