The effect of the magnitude of weight loss on non-alcoholic fatty liver disease: A systematic review and meta-analysis
Previous trials have reported that weight loss interventions help in improving biomarkers of non-alcoholic fatty liver disease (NAFLD). Due to lack of data, it is not clear if a dose-response relationship exists.
The author Koutoukidis and colleagues conducted a study titled “The effect of the magnitude of weight loss on non-alcoholic fatty liver disease: A systematic review and meta-analysis” published in the Metabolism Journal. The summary of findings is below:
Objective:
To assess the dose-response relationship between the magnitude of weight reduction and improvements in NAFLD.
Method:
Nine databases and trial registries were shortlisted before October 2020. Studies included were single-arm, non-randomized comparative, or randomized trials of weight-loss interventions in people with NAFLD. These studies mentioned the association between changes in weight and changes in blood, radiological, or histological biomarkers of liver disease. The review followed Cochrane methods and the risk of bias was measured using the Newcastle-Ottawa scale. Pooled unstandardized b coefficients were assessed using random-effect meta-analyses.
Findings:
The study reports the presence of a dose-response relationship between weight loss and improvements in blood biomarkers, namely ALT and AST. There were also improvements in radiological and histological markers, namely steatosis, ballooning, inflammation, and resolution of NAFLD/NASH. In patients with bariatric surgery, it was observed that higher weight loss resulted in better benefits for the liver. On the other hand, a weaker dose-response relationship was observed between weight loss and liver outcomes as compared to other types of treatment in individuals with bariatric surgery. The study also reports smaller improvements in liver markers in individuals with higher mean baseline BMI.
These findings could allow clinicians to put forward and discuss the benefits of weight loss with patients and also provide them with structured support.
Limitations:
Investigators considered a linear relationship between changes in weight loss and biomarkers of liver disease. Whereas, there are chances of the monotonic relationship as considered in other researches. The trials that did not report an association between changes in weight and biomarkers of liver disease in people with NAFLD were excluded. This might affect the findings. Although, heterogeneity is been introduced because studies used a range of methods to investigate the association between weight change and liver biomarkers and converted it to a common metric for pooling. The authors suggest interpreting this finding cautiously.
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