PPARGC1A and type 2 diabetes mellitus: When subjects were divided according to glucose tolerance status, the relation between average PPARGC1A methylation and whole-body insulin sensitivity remained significant in the NGT (β = 0.14 (0.006;0.28) P = 0.04) and the NGT/IFG/IGT (non-diabetic) group (β = 0.14 (0.02;0.27) P = 0.02), but not in the IFG/IGT or T2D group.