Allostatic load in relation to psychosocial stressors and health

Abstract

Epävakaa työura osoittautui terveysriskiksi keski-ikää lähestyvillä henkilöillä, kun taas onnistunut tunteidensäätely suojasi terveysriskin kohoamiselta. Ammattiaseman ja koulutuksen yhteys terveyteen oli näitä monimutkaisempi. Nämä tiedot käyvät ilmi Marja-Liisa Kinnusen väitöstutkimuksesta.Kinnunen tutki terveyden biopsykososiaalista näkökulmaa allostaattisen kuorman mallin avulla. Hän selvitti erilaisten elämän haasteellisten tilanteiden merkitystä mahdollisina stressitekijöinä, jotka saattaisivat aiheuttaa terveysriskin eli allostaattisen kuorman nousun. Allostaattinen kuorma on fysiologisten stressireaktioiden kasautuva, pitkäaikainen seuraus, joka voi johtaa sairauksien syntyyn. Sitä on mahdollista kuvata sekä elimistön säätelyjärjestelmien välittäjäaineiden että sydän- ja verisuonisairauksien riskitekijärypään, metabolisen oireyhtymän, avulla. Metabolinen oireyhtymä koostuu huonontuneesta sokeriaineenvaihdunnasta, poikkeavista veren rasva-arvoista, ylipainosta – erityisesti keskivartalolihavuudesta – ja kohonneesta verenpaineesta.

This longitudinal study investigated the long-term effects of psychosocial factors on allostatic load and the effects of allostatic load on health. Allostatic load refers to the activation of various physiological regulatory systems in response to stress, as well as their immediate and long-term effects on the body (McEwen & Stellar, 1993). In the present study, allostatic load was measured by eight variables: noradrenaline, dehydroepiandrosterone-sulfate, waist-to-hip ratio, glycosylated haemoglobin, high-density lipoprotein cholesterol, triglycerides, systolic and diastolic blood pressure. When the last six variables alone were used as an indicator of allostatic load, they were referred as metabolic syndrome, which is a well-known cluster of cardiovascular risk factors. The first goal of the study was to assess allostatic load across men and women at 42 years of age. Second, previous career instability was investigated as possible stressor leading to elevated allostatic load, and the association of allostatic load with concurrent psychosomatic symptoms was studied. Third, the relation of emotion regulation and dysregulation to metabolic syndrome was investigated including the possible mediating role of subjective health. Fourth, the relationship between long-term job strain and metabolic syndrome across sex and occupational groups was examined. Finally, the role of childhood and adulthood factors in the association between socioeconomic status (education and occupational status) and adult systolic and diastolic blood pressure was studied. The study was conducted as part of the Jyväskylä Longitudinal Study of Personality and Social Development (JYLS), which has been ongoing since 1968. The results revealed that 41.9% of men and 21.8% of women had elevated allostatic load at age 42. These individuals reported more psychosomatic symptoms than the others. Individuals with preceding unstable career assessed prospectively at age 36 had an over three-fold risk for high allostatic load six years later compared to individuals with a stable career history. Successful emotion regulation was associated with a reduced risk for metabolic syndrome. Unexpectedly, low metabolic syndrome was associated with high long-term job strain among higher white-collar workers of both sexes. Furthermore, high metabolic syndrome was associated with low long-term job strain in women. A weak association between low educational attainment and development of high blood pressure was found. Adulthood overweight and parents’ low occupational status were the key explanatory factors for the association between education and blood pressure. The findings implied that unstable career had long-lasting negative effects on physical health while successful emotion regulation turned out to be beneficial to physical health. The role of other work factors was more complicated and need further research.