Section outline

  • Lecture:  Multi-level etiologies of health in diverse populations, Part 2: Biological determinants, mediators and mechanisms

    One of the most active areas of health disparities research is understanding how social experiences get “under the skin” to influence health. As discussed in previous classes, behavioral factors and clinical care are important mechanisms, but study after study has shown that behaviors and medical care cannot fully explain the magnitude of social inequalities in health. In this class we will review key hypothesized mechanisms via which adverse social experiences change human physiology and have enduring effects on long term health outcomes.  Leading hypotheses include the role of epigenetic changes; dysregulation of stress responses via hypothalamic pituitary adrenal axis alterations; and physiologic triggers of behavioral patterns. We will discuss how these biological mechanisms directly relate to lifecourse models for the determinants of adult health. We will also discuss controversial perspectives on the role of genetic differences in creating social and racial inequalities in health.

    Faculty:  Kirsten Bibbins-Domingo and Maria Glymour

    Location:      Mission Hall 1406

    • Session Slides:

    • Slides for Biological Mechanisms Lecture File
    • Lecture3BiologicalMechanismsv8 File

    • Session Audio/Video Recording (Access restricted to registered students):

    • Required Reading:

    • Lecture5 BiologicalMechanisms ReadingReflectionsAssignment File
    • Gruenewald Seeman AllostaticLoad File
    • HertzmannBoyceAnnualReviews File
    • Weaver MaternalProgramming Epigenetic NatureNeuroscience File

    • Resources:

    • Assignment:  

      Questions Related to Week 3 Readings:

      1. Weaver et al propose that among rats, maternal behavior towards newborn pups influences their cortisol response to stress via epigenetic mechanisms that change the expression of glucocorticoid receptor gene for the rest of the pup’s life.  They argue that because epigenetic patterns are established at specific developmental periods, there is extreme time sensitivity to when the pup is exposed to particular maternal behaviors (licking and grooming, in this case), and maternal behavior before or after that sensitive period window is not as important.   Do you think this mechanism is relevant in humans?  If so, what behaviors are most analogous to “maternal licking and grooming”? 

      2.  Provide a brief proposal for a study that would allow you to assess whether epigenetic modifications in humans in response to maternal behavior influence subsequent health of the human (feel free to choose any health or behavioral outcome you think you can do this with, e.g., dementia or depression or smoking). Bonus if you can explain how you would approach this if we assume that the relevant epigenetic changes are tissue specific and occur in the brain. 

      3. Gruenewald, in contrast to Weaver, emphasizes the cumulative effects of SES adversity on a multi-system allostatic load measure.   Do you think that the Gruenewald findings are consistent, inconsistent, or unrelated to the Weaver findings?  Explain. 

       4. Hertzmann and Boyce argue that “it is not genes or environment, nor is it genes and environment, but rather it is gene-by-environment interactions that influence developmental trajectories.”  To what extent do you think that GxE interactions can contribute to major disparities along racial/ethnic, socioeconomic, or geographic dimensions?

    • Assignment Due Date:  January 24th at 12:00pm