The Effect of HIT in Patients With Non-alcoholic Fatty Liver Disease/Steatohepatitis

This pilot study aims to investigate whether 6 weeks of twice weekly High-intensity Interval Training (HIT) results in improvements in disease-specific measures, feelings of general well-being, physical fitness and cognitive function in patients with non-alcoholic fatty liver disease or non-alcoholic steatohepatitis.

The study aims to recruit up to 12 patients diagnosed with non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH) from the liver clinics at Ninewells Hospital, Dundee. Suitable patients who give informed consent will be assessed at baseline, again after 6 weeks of no intervention to act as a control period, and thirdly after 6 weeks of twice-weekly high-intensity interval training (HIT). Assessments will be performed with the patient fasted overnight, and will involve body composition measurements, blood pressure, a venous blood sample for circulating triglycerides, fasting glucose, insulin, liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and platelets. An oral glucose tolerance test will be performed using fingerprick capillary samples. Cognitive function tests for episodic memory, executive function and semantic memory will be performed and a questionnaire (SF-36) will be used to assess general well-being. Physical fitness will be assessed through a 12-minute walk test on a treadmill, which will allow estimation of maximal oxygen uptake capacity (VO2 max), and a "get up and go" test will be used to assess physical function. The exercise intervention will involve a 2 minute warm-up, cycling at 50 rpm before the participants will be asked to cycle at 100rpm and a weight will be added (7% body weight for men and 6% body weight for women) as resistance. The sprint will last 6 seconds and the participant will be asked to rest for at least 1 minute. This will be repeated for a total of 5 sprints in sessions 1-3, 6 sprints in session 4, 7 sprints in sessions 5\&6, 8 sprints in sessions 7\&8, 9 sprints in sessions 9\&10 and 10 sprints in sessions 11\&12. Exercise heart rate will be monitored and recorded. At least 3 days after the last HIT session the pre-intervention testing assessment will be repeated for a third time. Changes in measured variables will be analysed via repeated measures analysis of variance (ANOVA) with post-hoc testing of all variables.