By screening for chemical compounds that caused an amelioration or pejoration of insulin resistance in HDb or HWT cells using the ratio of pAkt/Akt fluorescence as an index, we identified five compounds that changed the pAkt/Akt ratio from among 90 small chemical compounds of the LOPAC-Pfizer library and seven drugs used for the treatment of diabetes mellitus. Here, AKT1 is linked to diabetes mellitus.