Pain-related stress in the Neonatal Intensive Care Unit and salivary cortisol reactivity to socio-emotional stress in 3-month-old very preterm infants

Psychoneuroendocrinology. 2016 Oct:72:161-5. doi: 10.1016/j.psyneuen.2016.07.010. Epub 2016 Jul 10.

Abstract

Very preterm (VPT) infants are hospitalized in the Neonatal Intensive Care Unit (NICU) and exposed to varying levels of skin-breaking procedures (pain-related stress), even in absence of severe clinical conditions. Repeated and prolonged pain exposure may alter hypothalamic-pituitary-adrenal (HPA) axis reactivity in VPT infants. During the post-discharge period, altered HPA axis reactivity has been documented in response to non-social stressors, using salivary cortisol as a biomarker. However, little is known about the effects of NICU pain-related stress on subsequent HPA axis reactivity to socio-emotional stress in infants. We examined the relationship between pain-related stress in NICU and HPA axis reactivity (i.e., salivary cortisol reactivity) to an age-appropriate socio-emotional condition in 37 healthy VPT infants compared to 53 full-term (FT) controls. The number of skin-breaking procedures was obtained across NICU stay for VPT infants. At 3 months (corrected age for prematurity), all infants participated in the maternal Face-to-Face Still-Face (FFSF) procedure, in order to assess HPA axis reactivity to socio-emotional stress (i.e., maternal unresponsiveness). VPT infants exhibited a blunted salivary cortisol reactivity, which was associated with the amount of skin-breaking procedures during NICU: greater pain-related stress predicted lower salivary cortisol reactivity, adjusting for neonatal confounders. These findings further advance our knowledge of how early exposure to pain-related stress in NICU contributes to the programming of an altered HPA axis reactivity to socio-emotional stress in 3-month-old VPT infants, even in the absence of major perinatal complications.

Keywords: Cortisol; Hypothalamic-pituitary-adrenal axis; Still-Face; Stress; Very preterm infants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Female
  • Humans
  • Hydrocortisone / metabolism*
  • Hypothalamo-Hypophyseal System / metabolism
  • Hypothalamo-Hypophyseal System / physiopathology*
  • Infant
  • Infant, Extremely Premature*
  • Intensive Care Units, Neonatal*
  • Male
  • Pain / complications*
  • Pituitary-Adrenal System / metabolism
  • Pituitary-Adrenal System / physiopathology*
  • Stress, Psychological / metabolism
  • Stress, Psychological / physiopathology*

Substances

  • Hydrocortisone