About a quarter of adults in the UK and worldwide show some sign of fatty liver. People with excess body weight are more likely to develop fatty liver. The build-up of fat in the liver can cause inflammation and scarring which can lead to liver cancer and heart disease.
No drug is currently available to treat fatty liver disease. Clinical guidelines worldwide recommend that doctors advise people to lose weight, but rarely recommend structured treatment programmes to support weight loss. The authors argue that guidelines should now be updated based on the new research.
In this study, funded by the National Institute for Health Research Oxford Biomedical Research Centre, the researchers looked at 22 trials that compared doctors’ usual practice of advising weight loss with offering a structured weight loss programme in more than 2,500 people with non-alcoholic fatty liver disease worldwide. They found that offering people a structured weight loss programme achieved greater weight loss compared with simple advice. This improved the health of their liver measured using blood tests, ultrasound, imaging, or liver biopsies.
“Although it is generally assumed that weight loss improves liver disease, this is the first study that looked at all the available evidence to show how the liver changed with weight loss. There is no perfect measure of liver disease, but whichever way we looked at it, the bottom line was the health of the liver improved with weight loss,” says lead researcher Dr Dimitrios Koutoukidis of Oxford University’s Nuffield Department of Primary Care Health Sciences.
“As a clinician,” says co-author and practicing GP, Professor Paul Aveyard of Oxford University’s Nuffield Department of Primary Care Health Sciences, “what this research shows is that there is consistent evidence that referring people with non-alcoholic fatty liver disease to weight loss programmes is likely to improve their liver disease compared with simply advising people to lose weight. As this disease is so common, if this evidence gets adopted into clinical guidelines and implemented in practice, there is scope for huge impact. That’s good news for patients and for clinicians who have been uncertain about what they could do to help.”
The researchers looked at the liver using blood tests, ultrasound, imaging, and biopsy. Although not all studies evaluated all outcomes, the study showed clinically meaningful improvements across a range of markers, such as enzymes released by liver damage, liver fat, and presence of advance liver disease. The study did not find any evidence that liver scarring (fibrosis) improved or worsened and most studies examined outcomes at around six months.
The researchers recommend that future trials of weight loss for non-alcoholic fatty liver disease should include longer-term follow up and examine how weight regain may affect the liver and patient outcomes.
Koutoukidis et al. JAMA Internal Medicine