- Elderly who were aging in poor health, i.e., lower muscle strength were found to be raised in economically disadvantaged situations in childhood.
- Disruption of normal physiological functioning caused by chronic stress in childhood might change the body's ability to maintain good health over time.
- Early and lasting stress can, therefore, alter the system's response to stress, affecting, in particular, the general health status in old age.
A strong link between poor economic status in childhood and the health of the same individuals as older adults have been identified in a new study. The findings of this study are published in the Age and Ageing journal.
As part of the "National center of Competence in Research - NCCR LIVES" funded by the Swiss National Science Foundation, researchers at the University of Geneva (UNIGE) examined data from more than 24,000 people aged 50 to 96 living in 14 European countries.
Socio-economically disadvantaged individuals in childhood were found to be at greater risk of low muscle strength at an older age - a good indicator of their overall health status.
The scientists suggest that physiological deregulation caused by chronic stress in childhood might change the body's ability to maintain good health a long time.
Boris Cheval and Stéphane Cullati, researchers at the NCCR LIVES and at the UNIGE Faculty of Medicine, sought to answer this question. To do so, they analyzed nearly 100,000 data from the Survey of Health, Ageing, and Retirement in Europe, a 12-year population survey conducted by the European Union to study the economic, social and health status of older people.
Thus, 24,179 participants, half of them men and half women, were included in the analysis. Participants' gripping strength was assessed with portable dynamometer - data that well predicts the overall health status - and compared to a measure of four socioeconomic indicators of participants at age 10.
The indicators were: the occupation of the primary breadwinner, the number of books at home - a surprisingly reliable indicator of children's future health - the quality of housing and the number of people living in it compared to the number of rooms.
"The results showed that people who faced poor socio-economic circumstances in childhood had on average less muscular strength than those who were better off in their early years," explains Boris Cheval.
"Even when adjusted to take into account socioeconomic factors and health behaviors (physical activity, tobacco, alcohol, nutrition) in adulthood, associations remained very significant, especially among women, who were often less susceptible to benefit from social mobility."
Social epidemiology studies often point to the indirect effects of social determinants of health: behaviors, for example, are not the same according to socio-economic status.
"Beyond that, our study suggests a direct, biological and lasting effect of a poor start in life,» says Boris Cheval. "To explain our findings, we hypothesize physiological deregulation induced by chronic stress due to the difficult circumstances of childhood."
Many studies indeed show that the physiological response to stress develops in childhood. Early and lasting stress can, therefore, alter the system's response to stress, affecting, in particular, the functioning of the immune and inflammatory systems, and the general health status.
Similarly, the level of household income in adulthood - a major stress factor in the event of financial problems - strongly correlates with objective muscle strength. "A growing body of scientific evidence indicates that the social is incarnated in the body, and thus shows the urgency, when it comes to health, to consider individuals under all of their life circumstances," adds Stéphane Cullati.
"In addition, our results show a notable difference between countries: Scandinavians are generally in better health, regardless of their socio-economic level. They also live in the most egalitarian countries in terms of access to health care and education."
Researchers will continue their analysis to determine how socio-economic systems mitigates the correlation between underprivileged childhood and poor health in old age and influences health trajectories.