TPO and Alzheimer disease: Moreover, in the study by Kapaki, AD patients had more abnormal anti-TPO levels (which were affected by gender, being higher in females, and which were reduced by treatment) compared to controls, while in the case-control study by Chang AD patients had lower levels of T3 and fT3 (which was however unaffected by donepezil) (Kapaki et al., 2006; Chang et al., 2018).