SUMMARY
Chronic distress has been linked with premature aging and earlier development of cardiometabolic diseases
and conditions (CMD) but identification of the biological mechanisms linking progression of these diseases with
chronic distress remains limited. Moreover, in epidemiologic studies, it is often difficult to assess chronic
distress comprehensively or to identify who is at higher risk for adverse physical health outcomes among those
who are distressed. Therefore, it is of great interest to identify biomarkers that may help indicate a prolonged
distress exposure and also provide insight into distress-linked biological alterations that are etiologically
relevant. Recent advances have been made in high-throughput technologies that can simultaneously measure
hundreds of small molecule metabolites in plasma (“metabolomics”). We hypothesize that chronic distress is
associated with multiple changes in circulating levels of small molecule metabolites. Our three aims are to 1)
evaluate specific plasma metabolite levels in women with and without chronic distress. We hypothesize chronic
distress is associated with circulating levels of multiple metabolites, including positive associations with
isoleucine and phenylalanine, and specific lysophosphatidylethanolamine and phosphatidylcholine lipids, and
an inverse association with glycine; 2) derive and validate a plasma metabolomics score that separates women
with and without chronic distress; 3) assess associations between the individual metabolites and metabolomics
score with CMD risk. Our studies will utilize the rich questionnaire and biospecimen resources from three large
cohorts of women, the Nurses’ Health Study (NHSI), NHSII, and Women’s Health Initiative (WHI). We posit
shared patterns of metabolic alterations across different forms of distress, and we will therefore consider
several common forms of distress manifested by symptoms of depression, anxiety, or post-traumatic stress
disorder (PTSD). For discovery, we will use two independent datasets with existing metabolomics profiles: 226
women from the NHSII Mind Body Substudy (MBS) and 328 women from WHI, all of whom completed detailed
questionnaires on depression, anxiety, and key covariates and also provided a blood sample. For validation,
we will utilize 3 independent data sets from NHSI and NHSII. We will compare metabolomic profiles among
women without (n=360) and with chronic distress as characterized by PTSD (n=120), anxiety (n=120), or
depression (n=120). Finally, in two prospective nested case-control studies, identified metabolites and derived
metabolomic profiles will be evaluated in relation to risk of CHD (WHI, case n=1,105) and diabetes (NHS, case
n=1,000). The use of multiple independent but complementary and detailed data sets in women for discovery
and validation of distress-linked plasma metabolites/score will help ensure our findings are reliable and
reproducible. Discovery of metabolic pathways dysregulated by chronic distress will help elucidate potential
biologic pathways linking distress and CMD, thus generating new targets for intervention as well as provide an
objective measure of chronic distress that can be used in other large prospective studies.