Impact of Home-Based Aerobic and Resistance Training in Chronic Liver Disease: a Randomized Control Trial

The goal of this clinical trial is to evaluate whether home-based exercise interventions, including aerobic exercise (AE) and a combination of aerobic and resistance exercise (ARE), can improve physical and health-related outcomes in patients with chronic liver disease (CLD). The primary population includes adult patients with CLD experiencing complications such as sarcopenia, malnutrition, and fatigue.

The main questions it aims to answer are:

Does home-based ARE improve oxygen consumption, muscle strength, and physical frailty more effectively than AE or no exercise? Can home-based exercise reduce fatigue and improve quality of life and health-related behaviors?

Researchers will compare the outcomes of three groups:

Home-based AE group Home-based ARE group Control group (physical activity counselling)

Participants will:

Perform an 8-week home-based exercise program based on their group allocation (either AE or ARE).

Undergo evaluations before and after the intervention, including:

Oxygen consumption (via cardiopulmonary exercise testing) Muscle strength (using a hand dynamometer and respiratory muscle strength tests) Body composition (via bioelectrical impedance analysis and skinfold thickness measurements) Quadriceps muscle thickness and cross-sectional area (using muscle ultrasound) Muscle oxygenation Fatigue levels (using the Fatigue Severity Scale) Physical frailty (using the Liver Frailty Index) Quality of life (using the Chronic Liver Disease Questionnaire) Health-related lifestyle behaviors (using the Health-Promoting Lifestyle Profile II)

This randomized controlled trial was designed to evaluate the effects of an 8-week home-based exercise program on physical and health-related outcomes in patients with Chronic Liver Disease (CLD). The study included three groups: Aerobic Exercise (AE), Aerobic and Resistance Exercise (ARE), and a control group. Below are the details of the interventions and measurement techniques utilized in the study.

Study Groups and Interventions

1. Aerobic Exercise (AE) Group:

   Exercise Protocol: Participants engaged in moderate-intensity walking exercises three non-consecutive days per week. The intensity was set at 40-60% of peak VO2 (measured by cardiopulmonary exercise testing), or based on the perceived exertion scale (Borg 4-6) for those on beta-blockers.

   Session Structure:
   * 5 minutes warm-up: Stretching or light walking.
   * 20 minutes aerobic walking at target intensity.
   * 5 minutes cool-down: Stretching or light walking.

   Monitoring and Equipment: Heart rate monitoring was performed using Mi Smart Band 4. Sessions were conducted via video conferencing through WhatsApp, and pre-, during, and post-exercise feedback was recorded regarding heart rate, fatigue, and dyspnea.

   Safety Measures: Participants exercised in a safe indoor space cleared of obstacles, using appropriate footwear.
2. Aerobic and Resistance Exercise (ARE) Group:

   Exercise Protocol: Participants followed a combined regimen:

   Aerobic exercises (3 days/week) were conducted following the AE protocol. Resistance training (2 days/week) was performed with elastic resistance bands (TheraBand) set at 40-50% of 1RM.

   Resistance Training Exercises:
   * Targeted major muscle groups.
   * Each exercise involved 3 sets of 10 repetitions, with 1-3 minutes of rest between sets.
   * Resistance exercises were demonstrated and practiced during an initial session to ensure adherence.
   * Monitoring and Safety: Heart rate monitoring, perceived fatigue, and dyspnea were recorded before and after each session.
3. Control Group:

Participants received general guidance on physical activity benefits and were given Mi Smart Band 4 for activity monitoring.

Weekly phone calls were conducted to encourage increased step counts. Step counts were recorded during the first and eighth weeks for comparison.

Measurements and Assessments

Oxygen Consumption:

Measured using Cardiopulmonary Exercise Testing (CPET) on a treadmill (COSMED, Quark RMR) with the Modified Bruce Protocol. Peak VO2 and anaerobic thresholds were recorded, along with parameters such as ventilatory efficiency, heart rate, and metabolic equivalents.

Muscle Oxygenation:

Measured during CPET using near-infrared spectroscopy (NIRS) (Moxy, Fortiori Design LLC). Parameters included SmO2 and total hemoglobin changes (THb).

Peripheral Muscle Strength:

Assessed using a digital hand dynamometer (LaFayette Instrument Company) and isometric contractions. Strength of various muscle groups (e.g., quadriceps, hamstrings, shoulder abductors) was evaluated using standardized positions.

Respiratory Muscle Strength:

Maximal inspiratory (MIP) and expiratory pressures (MEP) were measured using a portable mouth pressure device (Micro RPM). Results were recorded in cmH2O and compared to age- and gender-specific predicted values.

Body Composition:

Measured using Bioelectrical Impedance Analysis (BIA) (Bodystat QuadScan 4000). Parameters included body fat percentage, lean mass, and phase angle. Skinfold measurements were performed using a caliper, and quadriceps muscle thickness and cross-sectional area were evaluated using ultrasound.

Frailty:

Evaluated using the Liver Frailty Index (LFI), which includes grip strength, sit-to-stand time, and balance tests. Scores classified participants as robust, pre-frail, or frail.

Physical Activity Levels:

Assessed using the International Physical Activity Questionnaire-Short Form (IPAQ). Scores were calculated in MET-min/week and classified as inactive, minimally active, or sufficiently active.

Fatigue:

Measured using the Fatigue Severity Scale (FSS), with responses recorded via an online form before and after the intervention.

Quality of Life:

Evaluated using the Chronic Liver Disease Questionnaire (CLDQ), addressing abdominal symptoms, fatigue, systemic symptoms, activity, emotional functioning, and anxiety.

Health-Related Lifestyle Behaviors:

Assessed using the Health-Promoting Lifestyle Profile II (HPLP-II), covering six domains: spiritual growth, interpersonal relations, nutrition, physical activity, health responsibility, and stress management.

Statistical Analysis Data were analyzed using descriptive and inferential statistics. Continuous variables were expressed as mean ± SD or median (min-max), while categorical variables were summarized as frequencies and percentages.

Dependent group comparisons: Paired t-tests or Wilcoxon Signed Rank tests were applied.

Independent group comparisons: ANOVA or Kruskal-Wallis tests, followed by post hoc tests (Tukey HSD or Mann-Whitney U).

A p-value \<0.05 was considered statistically significant.

Eligibility Criteria:
Inclusion Criteria:

* Being followed up for chronic liver disease or listed on the liver transplant waiting list at the Hacettepe University Department of Internal Medicine, Division of Gastroenterology.
* Owning and being able to use a smartphone.
* Aged between 18 and 70 years.
* Receiving primary prophylactic treatment for gastroesophageal varices.
* Willingness to participate in the study.

Exclusion Criteria:

* Inability to own or use a smartphone.
* Participation in an exercise training program within the last year.
* Previous liver transplantation.
* High-risk varices without beta-blocker treatment.
* Presence of persistent hepatic encephalopathy.
* Hepatic hydrothorax.
* Pulmonary vascular complications of portal hypertension.
* Chronic renal failure requiring dialysis.
* Hemoglobin level below 10 g/dL.
* Creatinine level above 2 mg/dL.
* Human Immunodeficiency Virus (HIV) infection.
* Presence of hepatocellular carcinoma (HCC).
* Recent acute myocardial infarction.
* Uncontrolled arrhythmias causing symptomatic hemodynamic instability.
* Contraindications to maximal exercise testing.
* Physical or orthopedic conditions preventing home-based exercise training.
* Lack of willingness to participate in the study.