Variations in estrogen receptoragene and risk of dementia, and brain volumes on MRI.

The role of estrogens in Alzheimer's disease (AD) is controversial. We investigated the association between well-recognized, and potentially functional, polymorphisms in the estrogen receptor (ER)agene and the risk of AD in a prospective study of 6056 Caucasian older men and women aged 55 years and over. In a subset of 468 participants, we assessed volumes of the hippocampus and amygdala, which have a high density of ERa, with brain magnetic resonance imaging (MRI) (1.5?T MR unit). During a total of 35?405 person-years of follow-up (mean per persons 5.8 years), 312 new cases of dementia were detected, of whom 230 were diagnosed with AD. Neither the PvuII nor the XbaI polymorphism or haplotypes thereof were associated with the risk of all-cause dementia or AD. In contrast, we found that nondemented women who carried the PvuII p allele or haplotype‘px’had smaller amygdalar volumes on MRI in an allele-dose-dependent fashion. Total amygdalar volume was 4.50 (SE 0.10) in PP genotype, 4.45 (SE 0.06) in Pp genotype, and 4.18?ml (SE 0.08) in pp genotype (P trend=0.008). Further studies are required to investigate whether this smaller amygdalar volume has functional significance.Molecular Psychiatry (2004) 9, 1129-1135. doi:10.1038/sj.mp.4001553 Published online 20 July 2004 [ABSTRACT FROM AUTHOR]