Maternal age of 40 years and over was found to be suggestively associated with a higher risk of Alzheimer's disease (overall relative risk = 1.7; 95%

Later research found the father's advanced age and not the mother's age associated with a greater risk of Alzheimer's. See Bertram:

(Paternal age is a risk factor for Alzheimer disease in the absence of a major gene
Journal neurogenetics
Publisher Springer Berlin / Heidelberg
ISSN 1364-6745 (Print) 1364-6753 (Online)
Issue Volume 1, Number 4 / August, 1998
Category Original article
DOI 10.1007/s100480050041
Pages 277-280
Subject Collection Biomedical and Life Sciences
SpringerLink Date Thursday, February 19, 2004



Authors
L. Bertram1, R. Busch2, M. Spiegl1, N. T. Lautenschlager1, U. Müller3, A. Kurz1
1Department of Psychiatry, Technical University Munich, Möhlstrasse 26, D-81675 Munich, Germany
2Department of Medical Statistics and Epidemiology, Technical University, Munich, Germany
3Department of Human Genetics, Justus-Liebig University, Giessen, Germany


Abstract

We compared the parental age at birth of patients with Alzheimer disease (AD) with that of cognitively healthy control subjects. Within 206 carefully diagnosed AD patients, two groups were distinguished according to the likelihood of carrying a major gene for AD (MGAD). This likelihood was calculated by applying a Bayesian approach which incorporates data on aggregation of the disease, age at onset, and "censoring" ages within the family. All AD patients were ranked by MGAD probability. According to the sample's quartiles, two subgroups were defined representing the 52 individuals with the lowest and the 52 with the highest MGAD probability. Age at onset of dementia, education, and apolipoprotein E )v4 allele frequencies were not statistically different between the two groups. Fathers of patients with a low MGAD probability were significantly older (35.7-8.1 years) than fathers of both other groups (high MGAD probability 31.3-6.9 years, P=0.004; controls 32.6-6.8 years, P=0.04, n=50). The differences for mothers were less pronounced and not statistically significant. These findings suggest that increased paternal age is a risk factor for AD in the absence of a major gene, whereas increased maternal age and AD are associated only weakly and independently of genetic disposition.)


Maternal age of 40 years and over was found to be suggestively associated with a higher risk of Alzheimer's disease (overall relative risk = 1.7; 95%








1: Int J Epidemiol. 1991;20 Suppl 2:S21-7. Links
Maternal age and Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group.Rocca WA, van Duijn CM, Clayton D, Chandra V, Fratiglioni L, Graves AB, Heyman A, Jorm AF, Kokmen E, Kondo K, et al.
SMID Centre, Florence, Italy.

To investigate the possible association between Alzheimer's disease and late maternal age at index birth, we conducted a collaborative re-analysis of existing case-control data sets. Of the 11 studies participating in the EURODEM project, four were included in the analyses regarding maternal age. In all four studies, cases were matched to controls by age and gender, and only population controls were considered. Analyses were conducted on the individual data sets, on the pooled sample, and on subgroups defined by gender, age at onset, and familial aggregation of dementia. Maternal age of 40 years and over was found to be suggestively associated with a higher risk of Alzheimer's disease (overall relative risk = 1.7; 95% confidence intervals: 1.0-2.9). In subgroup analyses, the association was statistically significant for women and for sporadic cases. Adjustments for education or analyses restricted to case-control pairs matched by type of respondent did not modify these results noticeably. The association was confirmed by a test of consistency with the Down's syndrome risk model; results of this test were again more definite for sporadic Alzheimer's disease. In addition, three of the four studies also suggested an increased risk for maternal age at index birth between 15 and 19 years (overall relative risk = 1.5; 95% confidence intervals: 0.8-3.0). Although consistency across studies was not always complete, only some of the increased relative risks reached statistical significance, and information regarding maternal age obtained through a next-of-kin interview may have limitations, our study suggests that both early and late maternal age should be further investigated as possible risk factors for Alzheimer's disease.