Web-Based Exercise as an Effective Complementary Treatment for Patients With Nonalcoholic Fatty Liver Disease: Intervention Study (Preprint)

BACKGROUND Physical inactivity is a major risk factor for nonalcoholic fatty liver disease (NAFLD). Exercise-based prevention interventions for improving cardiorespiratory fitness are a recommended complementary treatment for NAFLD. Achievement of minimally effective physical activity to improve cardiorespiratory fitness among patients typically involves high personal and financial expenses in face-to-face settings. We designed an eHealth approach for patients with NAFLD to improve the cardiorespiratory fitness and report the first results of the HELP (Hepatic Inflammation and Physical Performance in Patients With NASH [nonalcoholic steatohepatitis]) study. OBJECTIVE We aimed to assess the effectiveness of an 8-week, tailored, Web-based exercise intervention for cardiorespiratory fitness improvement, expressed as peak oxygen uptake (peak volume of oxygen [VO2peak]), in patients with histologically confirmed NAFLD. METHODS In a 24-month period, 44 patients were enrolled into an 8-week, prospective, single-arm study with 12 weeks of follow-up. After a medical examination and performance diagnostics, a sports therapist introduced the patients to a Web-based platform for individualized training support. Regular individual patient feedback was provided to systematically adapt the weekly exercise schedule, which allowed us to monitor and ensure patient adherence to strength and endurance training and optimize the step-wise progressive exercise load. Exercise progression was based on an a priori algorithm that considered the subjective rate for both perceived exhaustion and general physical discomfort. The VO2peak was assessed at baseline and at the end of the study by spiroergometry. RESULTS A total of 43 patients completed the intervention with no adverse events. The VO2peak increased significantly by 2.4 mL/kg/min (8.8%; 95% confidence interval [CI]: 1.48-3.27; P<.001) accompanied by a reduction of 1.0 kg in a body weight (95% CI: 0.33-1.58; P=.004) and 1.3 kg in body fat mass (95% CI: 0.27-2.27; P=.01). In an exploratory analysis, step-wise logistic regression analysis revealed low body fat and VO2peak at baseline and the total minutes of endurance training during the intervention as main contributors to a positive change in VO2peak. Our predictive model indicated that the average patient with NAFLD needed 223 min for stabilization of VO2peak and 628 min for average improvement in VO2peak. However, in patients with a VO2peak approximately 20% higher than the average VO2peak, 628 min were only sufficient to stabilize the VO2peak and >40% reduction in the average fat mass would be required to achieve an average outcome. CONCLUSIONS This is the first study to show that patients with NAFLD can be effectively supported by a Web-based approach, which can increase the VO2peak to a similar extent as face-to-face interventions. Patients with low body fat and low VO2peak benefited the most from our intervention. In terms of future treatment strategies, NAFLD patients with high body fat may particularly benefit from body-fat reduction through a strict nutritional intervention, subsequently enabling a more effective exercise intervention. CLINICALTRIAL ClinicalTrials.gov NCT02526732; https://clinicaltrials.gov/ct2/show/NCT02526732 (Archived by WebCite at http://www.webcitation.org/74pXhXXfq) INTERNATIONAL REGISTERED REPOR RR2-10.2196/resprot.8607