PPARGC1B and heart disorder: PGC-1 is reduced in animal models of heart disease, accompanied by a switch of substrate use from fatty acids to glucose [45, 46], and PGC-1α is a potent regulator of gluconeogenesis via induction of phosphoenol pyruvate carboxykinase and glucose-6-phosphatase and increased tricarboxylic acid cycle flux [47–50].