Effects of Sociospatial Inequality on Exposure to Stress, Symptoms of Depression, and Cortisol Rhythms in Pregnancy

Objective

To investigate the effect of sociospatial inequality on exposure to stress, symptoms of depression, and cortisol rhythms during pregnancy.

Design

Secondary analysis of a cross-sectional observational study.

Setting

Outpatient women’s health clinic in an urban midwestern region of the United States.

Participants

Pregnant women in the second trimester of pregnancy (N = 67).

Methods

We performed a secondary analysis of salivary cortisol samples to compute average daily cortisol rhythms (diurnal slope, area under the curve, mesor, amplitude, and acrophase). We measured sociospatial inequality using the index of concentration at the extremes based on zip-code-level data from the American Community Survey. We used mixed-effects cosinor regression to examine the association among sociospatial inequality, exposure to stress, symptoms of depression, and cortisol rhythms, adjusting for multiple covariates.

Results

Sociospatial inequality was significantly associated with demographic variables (age, race, and education) and mental health variables (exposure to stress and symptoms of depression). We found a statistically significant curvilinear association between income-related sociospatial inequality and cortisol rhythms.

Conclusions

Participants who lived in areas of extreme income-related deprivation and privilege had higher amplitude cortisol rhythms, which potentially reflects heightened biological sensitivity to context, whereas women living in more moderate environments showed buffered cortisol rhythms.