Using 7 Goto-Kakizaki (GK) rats (a non-obese model that spontaneously develops T2DM early in life), and 7 age-matched Wistar control rats, we evaluated the protein levels of SIRT1, PGC-1α, and SIRT3, as well as the expression of mitochondrial respiratory complexes. This evidence concerns the gene SIRT1 and type 2 diabetes mellitus.