Nevertheless, various risk factors of diabetic cognition deficits, such as serum lipids (Kohlstedt et al., 2011), oxidative stress (Tota et al., 2012), and inflammation (Gadelha et al., 2015), could affect either the serum level or activity of ACE to a certain extent, and thus, we were unable to deduce from our data that none of these factors was significant in the early prediction of cognitive decline, except that ACE activity was related to logical memory. Here, ACE is linked to Mental deterioration.