Beneficial effects of lifestyle intervention in non-obese patients with non-alcoholic fatty liver disease

Abstract

Background & aims: Around 10-20% of patients with non-alcoholic fatty liver disease (NAFLD) are non-obese. The benefit of weight reduction in such patients is unclear. We aim to study the efficacy of lifestyle intervention in non-obese patients with NAFLD and to identify factors that predict treatment response.

Methods: A total of 154 community NAFLD patients were randomised to a 12-month lifestyle intervention programme involving regular exercise, or to standard care. The primary outcome was remission of NAFLD at Month 12 by proton-magnetic resonance spectroscopy. After the programme, the patients were prospectively followed until Year 6. The Asian body mass index (BMI) cut-off of 25 kg/m² was used to define non-obese NAFLD.

Results: Patients were assigned to the intervention (n = 77) and control (n = 77) groups (39 and 38 in each group had baseline BMI <25 and ≥25 kg/m², respectively). More patients in the intervention group achieved the primary outcome than the control group regardless of baseline BMI (non-obese: 67% vs. 18%, p <0.001; obese: 61% vs. 21%, p <0.001). Lifestyle intervention, lower baseline intrahepatic triglyceride, and reduction in body weight and waist circumference were independent factors associated with remission of NAFLD in non-obese patients. Half of non-obese patients achieved remission of NAFLD with 3-5% weight reduction; the same could only be achieved in obese patients with 7-10% weight reduction. By Year 6, non-obese patients in the intervention group remained more likely to maintain weight reduction and alanine aminotransferase normalisation than the control group.

Conclusions: Lifestyle intervention is effective in treating NAFLD in both non-obese and obese patients. Weight reduction predicts remission of NAFLD in non-obese patients, but a modest weight reduction may be sufficient in this population.

Lay summary: Some patients with non-alcoholic fatty liver disease (NAFLD) are non-obese. The optimal management of such patients is unclear. In this long-term follow-up study of a clinical trial, we show that remission of NAFLD can be achieved in 67% of non-obese patients after lifestyle intervention. The majority of patients can achieve NAFLD remission with modest weight loss of 3-10%. Non-obese patients are also more likely than obese patients to maintain weight reduction and normal liver enzymes in the long run.

Keywords: Body mass index; Magnetic resonance spectroscopy; Non-alcoholic steatohepatitis; Obesity; Transient elastography; Weight loss.