The effect of a multicomponent intervention on hepatic steatosis is partially mediated by the reduction of intermuscular abdominal adipose tissue in children with overweight or obesity; the EFIGRO project

<p>  </p> <p><strong>Objective</strong></p> <p>In adults, there is evidence that the improvement of metabolic associated fatty liver disease (MAFLD) depends on the reduction of myoesteatosis. In children, where the prevalence of MAFLD is alarming, this muscle-liver crosstalk has not been tested. Therefore, we aimed to explore whether the effects of a multicomponent intervention on hepatic fat were mediated by changes on intermuscular abdominal adipose tissue (IMAAT) in children with overweight/obesity.</p> <p><strong>Research design and methods</strong></p> <p>A total of 116 children with overweight/obesity were allocated to a 22-week family-based lifestyle and psychoeducational intervention (control group, N=57), or the same <em>plus</em> supervised exercise (exercise group, N=59). Hepatic fat percentage and IMAAT were acquired by magnetic resonance imaging at baseline and at the end of the intervention. </p> <p><strong>Results</strong></p> <p>Changes in IMAAT explained the 20.7% of the improvements in hepatic steatosis (P<0.05). Only children who meaningfully reduced their IMAAT (i.e., responders), improved hepatic steatosis at the end of the intervention (within-group analysis; responders: -20%, P=0.005 <em>vs.</em> non-responders: -1.5%, P=0.803). Between-group analysis showed greater reductions in favour to the IMAAT responders compared to the non-responders (18.3% <em>vs.</em> 0.6%, P=0.018) regardless of overall abdominal fat loss. </p> <p><strong>Conclusions</strong></p> <p>The reduction of IMAAT has a relevant role over the improvement of hepatic steatosis after a multicomponent intervention in children with overweight/obesity. Indeed, only those children who achieved a meaningful reduction in IMAAT at the end of the intervention reduced their percentage hepatic fat independently of abdominal fat loss. Our findings suggest that abdominal muscle fatty infiltration could be a therapeutic target for the treatment of MAFLD at childhood. </p>