Studies indicate a reduction in glucose metabolism as well as changes in brain energymetabolism and impaired neuronal insulin signaling in AD patients.14,90 Insulin signaling, as measured by phosphorylation of AkT,was also found to be impaired by Aβ1-42 injection in rathippocampus91 and incultured hippocampal neurons by physiological inhibition of IRS-1pTyr.89 Moreover, hyperinsulinemia alsopromotes Aβ1-42 increase in the CSF of normal elderly.92 However, the mechanisms by whichtype 2 diabetes and AD interaction occurs remain unknown. The gene discussed is INS; the disease is Alzheimer disease.