Stress is generally defined as demands that tax or exceed the adaptive capacity of an organism, which can result in psychological and biological changes. Oxidative stress is an imbalance between free radicals and antioxidants in the body which can ultimately cause adverse chemical reactions and may negatively impact health[1]. First author of our recent publication focusing on associations of oxidative stress and socioeconomic status and former Human Subjects & Sampling Core Trainee Stephanie Eick explained the significance within our studies: “Oxidative stress is measured through the biomarkers 8-iso-prostaglandin-F2α and the 8-iso-prostaglandin-F2α metabolite. These biomarkers usually increase in many pregnancy complications, such as preeclampsia and preterm birth. Therefore, knowing what leads to increases in these biomarkers is really important to improving maternal and child health.”
In this study, the team found that individuals at a socioeconomic disadvantage had elevated levels of oxidative stress. In this context, socioeconomic disadvantage includes factors such as having less than a college education, being unemployed, and not having private insurance. “This is important, because we know that individuals who are lower income or who have less than a high school education are more likely to deliver their baby early,” explains Eick. “Results from this study help us understand how, and through what biologic mechanism, that might happen.”
In this context, stress was categorized into three even groups to capture and analyze how different levels of varying stress were represented in the PROTECT cohort. In addition to this, researchers took the average of the three oxidative stress biomarkers across pregnancy. This was performed because these biomarkers were relatively stable over pregnancy and taking the average allowed the team to obtain a more stable estimate of oxidative stress. “In our statistical analysis, we used multiple imputation to handle missing data,” says Eick. “In epidemiologic studies, sometimes people don’t answer all of the questionnaire questions and multiple imputation is a way for us to still include people even if they did not answer all of our questions. This also helps to increase our statistical power. “
Although the team found that women who self-reported experiencing stress did not necessarily have higher oxidative stress levels, other studies have observed an association here and it is possible that there is an effect. Our researchers suggest that women who feel stressed should talk to mental health providers to help achieve a healthy pregnancy. The same can be said for other lifestyle factors. Both alcohol consumption and smoking status were associated with elevated oxidative stress in this study although these findings did not reach statistical significance.
This paper falls within the aims of the major goals of
PROTECT in its aim to identify risk factors for adverse birth outcomes via increased
oxidative stress, which builds upon a previous
paper published by the center and first author, Stephanie Eick. This study
helps to build on some of those findings by looking at how low socioeconomic
status might be linked to adverse birth outcomes.