(P27-088-25) An Examination of the Effects of FADS Indel Genotype on Stress Reactivity in Black Pregnant Women

Objectives: Black American women living in urban low-resourced areas are exposed to high levels of stress that impact their health throughout the lifespan, including during pregnancy. Fatty acid status is associated with improved stress regulation during pregnancy for Black women (Keenan et al., 2016). Genes associated with fatty acid metabolism may be important for understanding individual differences in stress physiology and stress related health problems in this population of women. The FADS Indel is a 22-base pair I(nsertion)-D(eletion) (Indel) polymorphism that controls FADS1 expression (Brenna & Kothapalli, 2022). Preliminary research has shown that women who have an insertion allele are at higher risk for stress related health complications, such as preterm birth (Li et al., 2024). In the present study we aim to further examine the relationship between FADS Indel genotype and stress reactivity in Black pregnant women.

Methods: The Nutrition and Pregnancy Study is a RCT of prenatal docosahexaenoic acid supplementation in 168 Black women aimed at improving maternal and infant health. We measured stress regulation using heart rate variability (HRV) as indexed by the root mean square of successive differences and salivary cortisol (CORT) levels before, during, and after exposure to a laboratory stressor at study enrollment, before randomization.

Results: Indel status was determined for 165 participants, stratified by genotype: D/D (16%, n = 27), I/D (47%, n = 77), and I/I (37%, n = 61); for analyses we combined I/D and I/I groups. We observed clinically meaningful group differences in HRV and CORT which approached statistical significance. HRV was similar for both groups before and during the stressor, but the magnitude of recovery was larger for the D/D group (F= 3.187, p = .076). CORT levels for the D/D group decreased in response to the stressor and were lower during recovery compared to the I/D and I/I group (F = 2.383, = p = .125).

Conclusions: Although the modest sample size impacted our statistical power, a signal was observed indicating an association between genotype and stress physiology that may add to emerging research on the interface among stress exposure, fatty acid status, and health outcomes for historically and currently marginalized racial groups.

Funding Sources: NHLBI and NICHD