Inter-generational social mobility following early life stress

INTRODUCTION. Socio-economic position (SEP) is a powerful source of health inequality. Less is known of early life conditions that may determine the course of adult SEP. We tested if early life stress (ELS) due to a separation from the parents during World War II predicts adult SEP, trajectories of incomes across the entire working career, and inter-generational social mobility. MATERIALS AND METHODS. Participants (n = 10,702) were from the Helsinki Birth Cohort Study 1934-44. Compared to the non-separated, the separated individuals attained a lower SEP in adulthood. The separated whose fathers were manual workers were less likely to be upwardly mobile from paternal occupation category to higher categories of own occupation, education, and incomes. The separated whose fathers had junior and senior clerical occupations were more likely to be downwardly mobile. Comparison of trajectories of incomes across adulthood showed that the difference between the separated and the non-separated grew larger across time, such that among the separated the incomes decreased. CONCLUSIONS. This life-course study shows that severe ELS due to a separation from parents in childhood is associated with socio-economic disadvantage in adult life. Even high initial SEP in childhood may not protect from the negative effects of ELS.

Childhood separation experience predicts HPA axis hormonal responses in late adulthood: a natural experiment of World War II

BACKGROUND

Animal models have linked early maternal separation with lifelong changes in hypothalamic-pituitary-adrenocortical (HPA) axis activity. Although this is paralleled in human studies, this is often in the context of other life adversities, for example, divorce or adoption, and it is not known whether early separation in the absence of these factors has long term effects on the HPA axis.

AIMS

The Finnish experience in World War II created a natural experiment to test whether separation from a father serving in the armed forces or from both parents due to war evacuation are associated with alterations in HPA axis response to psychosocial stress in late adulthood.

METHOD

282 subjects (M=63.5 years, SD=2.5), of whom 85 were non-separated, 129 were separated from their father, and 68 were separated from both their caregivers during WWII, were enlisted to participate in a Trier Social Stress Test (TSST), during which we measured salivary cortisol and, for 215 individuals, plasma cortisol and ACTH concentrations. We used mixed models to study whether parental separation is associated with salivary and plasma cortisol or plasma ACTH reactivity, and linear regressions to analyse differences in the baseline, or incremental area under the cortisol or ACTH curves.

RESULTS

Participants separated from their father did not differ significantly from non-separated participants. However, those separated from both parents had higher average salivary cortisol and plasma ACTH concentrations across all time points compared to the non-separated group. They also had higher salivary cortisol reactivity to the TSST. Separated women had higher baselines in plasma cortisol and ACTH, whereas men had higher reactivity in response to stress during the TSST. Participants who had experienced the separation in early childhood were more affected than children separated during infancy or school age.

CONCLUSIONS

Separation from parents during childhood may alter an individual's stress physiology much later in adult life.

Cardiovascular health of Finnish war evacuees 60 years later

BACKGROUND

Early life experiences might have long-term effects on health.

AIM

To assess prevalence of cardiovascular disease and diabetes in later life among individuals exposed to traumatic separation in early childhood due to World War II.

METHODS

Of the participants of the Helsinki Birth Cohort 1934-44 Study (n=2003), 320 had been evacuated abroad to temporary foster care in childhood. The remaining participants served as controls. The mean age at evacuation was 4.8 (SD=2.4) years and the mean duration of the evacuation was 1.7 (SD=1.0) years.

RESULTS

Cardiovascular morbidity was higher among the former war evacuees (14.7% versus 7.9%; odds ratio (OR)=2.0, 95% confidence interval (95% CI) 1.4-2.9; P<0.001). A similar difference in prevalence of type 2 diabetes was observed (19.7% versus 14.8%; OR=1.4, 95% CI 1.1-1.9, P=0.025). The former war evacuees were also more likely to be hypertensive (P<0.05). The effects on morbidity were not explained by age at testing or socio-economic circumstances in childhood or adulthood.

CONCLUSION

Early life traumatic events may extend lifelong effects on health. This study is among the first to show that early life trauma predicts higher prevalence of cardiovascular disease and type 2 diabetes in late adulthood, in a longitudinal clinical study setting.