Background: Naturalistic studies evaluate individuals in their usual way of living, presenting more "real-life" data regarding patients and their diseases.
Objective: To investigate demographic, clinical, and genetic factors that could be predictive of good response to cholinesterase inhibitors (ChEI) treatment in Alzheimer's disease (AD) and AD + cerebrovascular disease (CVD).
Patients and methods: A total of 129 patients were diagnosed with AD or AD + CVD and with mild-to-moderate dementia. After a 12-month treatment, 97 patients completed the study. They were evaluated at baseline and after three, six, and 12 months of ChEI (donepezil or rivastigmine or galantamine) use. APOE genotype and CYP2D6 polymorphisms were determined for all of the participants. In each visit, we used cognitive, functional, mood, and behavior scales. We classified patients according to their scores in the Mini-Mental State Examination (MMSE). Good responders were defined as those scoring ≥2 in the MMSE at 12 months.
Results: The rate of good clinical response was 27.8%. In a longitudinal analysis, the patients with mild AD and also good responders at three months were considered to be good responders at 12 months. There was no correlation between ChEI dose, APOE and CYP2D6 polymorphisms, and the pattern of clinical response.
Conclusion: A higher rate of good response was observed in this study compared to that in previous investigations. The pharmacogenetic aspects do not seem to have an influence in the response.
Keywords: APOE and CYP2D6 polymorphisms; Alzheimer's disease; cholinesterase inhibitors; predictive factors; response.