The relationship between age and fat infiltration in liver and muscle

The relationship between sarcopenia and non-alcoholic fatty liver disease (NAFLD) is intriguing and extremely topical, when we consider the increasing prevalence of the manifestations of NAFLD and non-alcoholic steatohepatitis (NASH) worldwide, together with the overwhelming burden of aging-related disease conditions such as sarcopenia. Such an association was described mainly in Eastern Asian populations and different indices of fat infiltration, including computed tomography (CT) were utilized. On the other hand, the evidence in the industrialized countries of the Western world is rather limited. The present findings replicate the association between liver and muscle fat infiltration in an older Western population, and using a densitometric definition. Such an association suggests the presence of common pathogenic mechanisms in the two conditions, and among these insulin resistance might play a crucial role; nonetheless, in older populations the epidemiological pattern is likely more complex and diseases such as NAFLD and sarcopenia may not necessarily coexist in the same subject.