GH1 and hypopituitarism: This relationship appears counterintuitive given i) GH is a highly lipolytic hormone, so its absence should theoretically lower the usage of lipids as metabolic fuel, ii) the severe hypopituitarism of dwarf mice should presumably lead to a slower rate of respiration, and iii) Ames dwarf mice have decreased levels of reactive oxygen species (ROS) [14–16], which given their increased metabolic rate, is opposite to the Rate of Living Hypothesis.