Klimiuk et al. revealed that the levels of CAT, GSH, TAS, and Px were decreased, whereas AOPP, Amadori products, AGE, N-formylkynurenine, as well as tryptophan and kynurenine fluorescence were increased in the stimulated and nonstimulated saliva of patients with severe dementia in comparison to those with mild to moderate stage of the disorder [26]. Here, CAT is linked to dementia.