HDAC1 and type 2 diabetes mellitus: Moderate exercise improves cardiac structure and function in humans with type 2 diabetes[59,60]; we therefore tested the hypothesis that moderate exercise would reduce O-GlcNAc in the type 2 diabetic heart, and would be associated with changes in the O-GlcNAc modification and activity of the mSin3A/HDAC1/2 transcription factor complex, which regulates hypertrophic genes.