Diabetic rats produced less SIK1, SIK1-Thr 182 and CRTC2-Ser 171 protein, but more SIK1-Ser577, CRTC2, PEPCK and G6Pase protein than normal control rats in the liver, which likely led to the development of NAFLD. Here, SIK1 is linked to metabolic dysfunction-associated steatotic liver disease.