0104 Biological Embedding and Sleep Quality in Adulthood: Evidence from a 30-year Prospective Longitudinal Cohort Study

Introduction Attenuation over the life course of hypothalamic-pituitary-adrenal (HPA) axis activity, such as reduced cortisol secretion, represents biological embedding of early-life stress. Biological embedding is implicated in myriad health concerns including disruptive sleep patterns. We hypothesized that attenuation of cortisol over the first half of the life-course will be negatively correlated with objectively indicated sleep quality in adulthood. Methods Cohort participants included females referred by child welfare agencies for having experienced intra-family childhood sexual abuse (CSA) at mean age 10.5 years. A counterfactual group of non-abused females from the same zip codes were demographically matched. The cohort was assessed at 7 timepoints across development longitudinally from 1987-2019. Resting cortisol was obtained through blood (waves 1-3) and saliva (waves 4-6). A formula approved by the US FDA was employed to convert salivary cortisol concentrations to blood-based equivalents: (serum µg/dL) = 5.177 + 15.132*(saliva µg/dL). Using a bilinear spline model – a model for tracking trajectories at different phases of development – pre-knot slopes (rates of change during childhood of cortisol, indicative of HPA attenuation and biological embedding) from waves 1 to 6 (or ages 6-32) were extracted. Wave 7 (mean age 36.1 years) included wrist actigraphy for a week. Ordinary Least Squares (OLS) regression examined whether cortisol slope from ages 6 to 32 predicted adult sleep. Results We found no group differences in sleep between participants exposed to CSA and demographically similar non-abused participants. Using individual slopes from T1-T6 models of cortisol levels, we observed a positive correlation between cortisol slope and sleep maintenance efficiency (r = 0.22; p < 0.05); sleep duration was not significant at Time 7. OLS regression showed that each additional year of increase in cortisol slope (µg/dL) was associated with 21.4% increase (p < 0.05) in mean sleep efficiency. Conclusion Findings suggest that sleep quality in middle adulthood was better when participants did not experience attenuation of cortisol (biological embedding of stress) earlier in the life course. Our study provides evidence of effects of biomarker-based biological embedding on sleep quality in middle adulthood among a sample of women maltreated as children and a matched control group. Support (if any)