JMIR Publications

ABSTRACT

Background:

Physical inactivity is a major risk factor for non-alcoholic fatty liver disease (NAFLD). Improvement of cardiorespiratory fitness (CRF) by exercise based prevention interventions is a recommended complementary treatment for NAFLD. Enabling patients to achieve minimally effective physical activity recommendations to improve CRF, typically requires high personal and financial expenses in face-to-face settings. Here we designed an eHealth approach for patients with NAFLD to overcome typical intrinsic and extrinsic barriers for the improvement of CRF (HELP-Study).

Objective:

We assessed the effectiveness of an 8-week tailored Web-based exercise intervention for the improvement of CRF, expressed as 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. 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 used to systematically adapt the weekly exercise schedule. This enabled to monitor and warrant patient adherence to strength and endurance training and to optimize the step-wise progressive exercise load. Exercise progression was based on an a priori algorithm taking the subjective rate for both, perceived exhaustion and general physical discomfort into account. VO2peak was assessed at baseline and at the end of the study by spiroergometry.

Results:

Forty-three patients completed the intervention with no adverse events reported. VO2peak significantly increased 8.5 % by 2.4 ml/kg/min (95% CI: 1.48 - 3.27, P < .0001) accompanied by a 1.0 kg (95% CI: 0.33 – 1.58, P = .004) body weight reduction and a 1.3 kg (95% CI: 0.27 – 2.27, P = .01) body fat mass reduction. In an exploratory analysis step-wise logistic regression analysis revealed low body fat and low VO2peak at baseline as well as 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 NAFLD patient needed 223 min for stabilization of VO2peak, while 628 min were required to achieve average improvement in VO2peak. However, in patients with a roughly 20 % higher than average VO2peak these 628 min were only sufficient to stabilize VO2peak and a more than 40 % lower than average fat mass would be required for such subjects with high VO2peak to achieve an average outcome.

Conclusions:

Here we show for the first time that patients with NAFLD can be effectively supported by a Web-based approach enabling similar increases in VO2peak as face-to-face interventions. Patients with low body fat and low VO2peak turned out to profit the most from our intervention. In terms of future treatment strategies, this implies that NAFLD patients with high body fat may particularly benefit from body fat reduction by a sharp nutritional intervention in first place thus enabling a more effective exercise intervention, subsequently. Clinical Trial: Clinicaltrials.gov: NCT02526732