As mentioned above, muscle aging is associated with diabetes and obesity, and in the present study, we compared the expressions of the FMOD and MSTN genes and those of genes related to muscle aging (Atrogin 1, Glb1), diabetes (RAGE, CD163) and intracellular lipid accumulation (CD36, PPARγ) in vivo and in vitro. Here, MSTN is linked to obesity due to melanocortin 4 receptor deficiency.