Marital status and risk of Alzheimer's disease - A French population-basedcohort study

Objective: To analyze the relationship between marital status and risk of A D or dementia. Methods: This study was carried out from the Personnes Agees QUID (PAQUID) cohort, an epidemiologic study on normal and pathologic agin g after age 65 years. The PAQUID cohort began in 1988. Individuals were fol lowed up at 1, 3, and 5 years, with an active detection of dementia. Marita l status was divided into four categories: widowed, never married, divorced or separated, and the reference category, married or cohabitant. The longi tudinal relationship between marital status and risk of incident AD or deme ntia was analyzed by a Cox model with delayed entry. Results: Among the 3,6 75 individuals initially not demented, 2,106 were married or cohabitants, 1 ,287 were widowers, 179 were never married, and 103 were divorced or separa ted. Among the 2,881 individuals reevaluated at least once for the risk of dementia during the 5-year follow-up, 190 incident cases of dementia were i dentified, including 140 with AD. The relative risks (RRs) of dementia (RR = 1.91, p = 0.018) and of AD (RR = 2.68, p < 0.001) were increased for the never-married individuals compared with those who were married or cohabitan ts. This excess of risk was specifically associated with AD. Adjustment for other risk factors of dementia (education, wine consumption), or for facto rs reflecting social environment, leisure activities, and depression, did n ot modify the risk of AD for never-married individuals (RR = 2.31,p = 0.02) . Conclusions: We confirmed an association between marital status and AD, w ith an excess risk observed among never-married individuals. This associati on may provide clues about the pathogenesis of AD.