Sociodemographic characteristics, clinical factors, and genetic polymorphisms associated with Alzheimer's disease

Objective Alzheimer's disease (AD) has a multifactorial etiology involving an interaction of genetic and environmental factors. The Apolipoprotein E e4 (ApoE e4) is the single most important genetic risk factor for sporadic AD. Our aim was to study the association between sociodemographic, clinical data and gene polymorphisms in patients with sporadic AD in a heterogeneous genomic Brazilian population with low educational levels. Methods We selected 169 sporadic AD patients and 97 controls older than 65 years and compared co-variables between them: age, years of education, vascular risk factors, genomic ancestry, and functional polymorphisms of ApoE, BDNF, COMT, and 5-HTTLPR. We also determined the genomic ancestry of all individuals. Results The average years of education was significantly smaller in the patient's group (p = 0.003), and they had a history of depression when compared with controls (p < 0.001). The carriers of ApoE e4 have an earlier onset of the disease (76.9 years) (p = 0.001) than ApoE e3 (79.5 years) (p = 0.024). Patients with Met allele of Val66Met have a tendency to later onset of disease (p = 0.056). There were no differences in the genomic ancestry between groups. Conclusion Low level of education and history of depression were associated with AD. Public policies and intensive observation of old-age patients with lifetime history of depression, especially APOE e4 carriers, could improve the well-being of our population. Copyright © 2012 John Wiley & Sons, Ltd.