Early-life risk factors and the development of Alzheimer's disease

Objective: To investigate the association of early-life factors with AD. Ba ckground: The early-life environment and its effect on growth and maturatio n of children and adolescents are linked to many adult chronic diseases (he art disease, stroke, hypertension, and diabetes mellitus), and these effect s are also linked to maternal reproduction. AD may have an early-life link. The areas of the brain that show the earliest signs of AD are the same are as of the brain that take the longest to mature during childhood and adoles cence. A poor-quality childhood or adolescent environment could prevent the brain from reaching complete levels of maturation. Lower levels of brain m aturation may put people at higher risk for AD. Methods: In a community bas ed case-control study (393 cases, 377 controls), we investigated the associ ation of early-life factors and AD. Early-life variables include mother's a ge at patient's birth, birth order, number of siblings, and area of residen ce before age 18 years. Patient education level and apolipoprotein E (APOE) genotypes were also included in the analysis. Results: Area of residence b efore age 18 years and number of siblings are associated with subsequent de velopment of AD. For each additional child in the family the risk of AD inc reases by 8% (OR = 1.08, 95% CI = 1.01 to 1.15), More controls compared wit h cases grew up in the suburbs (OR = 0.45, 95% CI = 0.25 to 0.82), APOE eps ilon 4 and the patient's education level did not confound or modify the ass ociations. Conclusions: The early-life childhood and adolescent environment is associated with the risk of AD.