SIRT5 and Hyperglycemia: Mice lacking both SIRT3 and SIRT5 (Sirt3−/−Sirt5−/−) were equally susceptible to STZ-induced hyperglycemia compared to control littermates of various genotypes, including Sirt3+/−Sirt5+/−, Sirt3−/−Sirt5+/−, and Sirt3+/−Sirt5−/− mice (Fig. 8a).