INS and type 2 diabetes mellitus: 2007). These inconsistencies may be due to the extent and duration of hyperglycemia as patients with type 2 diabetes may remain undiagnosed and therefore untreated for years, whereas the rats in this study were only diabetic for a period of 4 weeks. Elevated intrinsic mitochondrial function may be due to a compensatory effect, although this remains speculative. Insulin treatment has in humans been shown to decrease mitochondrial proton leak, but the effects of insulin on mitochondrial function are also not well understood and remain to be elucidated (Rabøl et al. 2009).