Among couples living together for a long time, women are more prone than men to suffer the effects of allostatic load or the negative accumulation of stress on the body.

Chronic stress that develops over decades in long-term couples does not have the same effect on men as on women: the latter is more likely to display negative physiological markers than their spouse, according to a study published in the scientific journal Psychosomatic Medicine .

This is the conclusion reached by Professor Robert-Paul Juster , of the Department of Psychiatry and Addictology at the University of Montreal, and researcher Yan-Liang Yu, of Howard University, based on data taken from the Health and Retirement Study – an American longitudinal study on health and retirement.

“Yan-Liang Yu is a sociology researcher who has long been interested in how the health and well-being of couples are mutually shaped,” says Robert-Paul Juster. He focused on several studies examining the correlation between intimate partners' lifestyles and their mental and physical health problems, but few studies have examined how couples' health synchronization manifests itself “under the skin”, that is to say on the physiological level.”

Chronic stress and allostatic load

Specialist in the physiology of stress, Robert-Paul Juster therefore decided to collaborate with Yan-Liang Yu to answer this question as part of a project aimed at studying how the allostatic load of older American heterosexual partners manifests itself. The two researchers began their collaboration on allostatic load while they were postdoctoral fellows at Columbia University in New York.

“Allostatic load is a concept that refers to the negative consequences of stress on the body which accumulate over time,” explains the UdeM professor. Stress leads to the production of cortisol – the stress hormone – which triggers a cascade of adaptive events in the body.”

However, when stress is chronic, this adaptation translates into negative consequences on the body, particularly on the cardiovascular, neuroendocrine, inflammatory and metabolic levels, so that it gradually reduces the body's ability to respond adequately to stress. .

Data from 2,338 elderly couples under the microscope

The two researchers' analysis is based on national data from the Health and Retirement Study. Their project consisted of examining interpartner associations of allostatic load among 2,338 long-term American couples of different sexes (i.e. 4,676 people) over a period of four years using a dyadic approach that took into account their social and economic profiles and of their state of health, including a variety of physiological indicators.

Allostatic load was calculated from immune (C-reactive protein), metabolic (high-density lipoprotein cholesterol, total cholesterol and glycosylated hemoglobin), renal (cystatin C), cardiovascular (systolic and diastolic blood pressure, pulse) and anthropometrics (body mass index and waist circumference).

Women more affected by allostatic load

Initial data show that allostatic loads within couples were significantly correlated with each other, which the researchers believe means that couples are physiologically synchronized, perhaps for a variety of reasons such as emotional, social, and family environments. shared and mutually influenced lifestyle habits.

“However, four years later, this marital synchronization in allostatic load was more notable in women than in men, which suggests that the well-being of spouses could be more influenced by their spouse than the reverse. This situation would thus testify to the traditional gendered socialization of attention to interpersonal relationships,” reports Robert-Paul Juster.

The authors of the study specify that this increased allostatic load for women was not associated with a decrease in the quality of the relationship between the partners.

“Our results suggest that older couples' physiological responses to environmental stress are not only linked simultaneously, but that associations persist after four years, suggesting long-term impacts of psychosocial context and partners' physiology. 'one on top of the other', they conclude.