Life-Course Socioeconomic Position and Hippocampal Atrophy in a Prospective Cohort of Older Adults
Psychosom Med. 2017-01-01; 79(1): 14-23
DOI: 10.1097/psy.0000000000000365
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Elbejjani M(1), Fuhrer R, Abrahamowicz M, Mazoyer B, Crivello F, Tzourio C, Dufouil C.
Author information:
(1)From the Department of Epidemiology, Biostatistics, and Occupational Health
(Elbejjani, Fuhrer, Abrahamowicz), McGill University, Montreal, Quebec, Canada;
CNRS (Mazoyer, Crivello), GIN UMR5296, Bordeaux, France; CEA (Mazoyer,
Crivello), GIN UMR5296, Bordeaux, France; University of Bordeaux (Mazoyer,
Crivello, Tzourio, Dufouil), Bordeaux, France; and INSERM U897 and CIC-1401
(Tzourio, Dufouil), Bordeaux School of Public Health, Bordeaux, France.
OBJECTIVE: Low socioeconomic position (SEP) has been linked to an increased risk
of dementia and cognitive decline. However, little is known about the
association between SEP and morphologic brain changes in older age. This study
examines the relationships between indicators of life-course SEP with both
hippocampal volume (HcV) and HcV loss in a population-based cohort of 1328 older
adults aged 65 to 80 years.
METHODS: Multivariable linear regression models were used to estimate the
associations of SEP with baseline HcV and the annual rate of HcV atrophy
according to three life-course conceptual models: the sensitive/critical periods
model (which explored SEP in specific periods: in childhood [using parental
education], early adulthood [based on participants’ education], and midlife
[based on participants’ socioprofessional group]); the accumulation-of-risk
model (life-course cumulative SEP), and the social mobility model (life-course
SEP trajectories).
RESULTS: Participants with lower midlife SEP had smaller HcV (-0.08 cm; 95%
confidence interval, -0.15 to -0.01) and 0.17% (95% confidence interval,
0.04%-0.30%) faster hippocampal atrophy than participants with higher midlife
SEP. Childhood and early adulthood SEPs were not related to hippocampal
measures. The accumulation-of-risk and the social mobility models revealed that
the accumulation of socioeconomic disadvantage and declining socioeconomic
trajectories were related to faster hippocampal atrophy.
CONCLUSIONS: In this cohort of older adults, lower socioprofessional attainment
in midlife and disadvantageous life-course socioeconomic position were
associated with faster hippocampal atrophy, a cerebral change linked to
cognitive disorders. Results support the hypothesized links between
socioenvironmental exposures related to stress and/or cognitive enrichment and
brain/cognitive reserve capacities.