Low-Level Prenatal and Postnatal Blood Lead Exposure and Adrenocortical Responses to Acute Stress in Children

By Gump, Brooks B.; Stewart, Paul et al. | Environmental Health Perspectives, February 2008 | Go to article overview
Save to active project

Low-Level Prenatal and Postnatal Blood Lead Exposure and Adrenocortical Responses to Acute Stress in Children


Gump, Brooks B., Stewart, Paul, Reihman, Jacki, Lonky, Ed, Darvill, Tom, Parsons, Patrick J., Granger, Douglas A., Environmental Health Perspectives


BACKGROUND: A few recent studies have demonstrated heightened hypothalamic--pituitary--adrenal (HPA) axis reactivity to acute stress in animals exposed to heavy metal contaminants, particularly lead. However, Pb-induced dysregulation of the HPA axis has not yet been studied in humans.

OBJECTIVE: In this study, we examined children's cortisol response to acute stress (the glucocorticoid product of HPA activation) in relation to low-level prenatal and postnatal Pb exposure.

METHODS: Children's prenatal blood Pb levels were determined from cord blood specimens, and postnatal lead levels were abstracted from pediatrician and state records. Children's adrenocortical responses to an acute stressor were measured using assays of salivary cortisol before and after administration of a standard cold pressor task.

RESULTS: Pb exposure was not associated with initial salivary cortisol levels. After an acute stressor, however, increasing prenatal and postnatal blood Pb levels were independently associated with significantly heightened salivary cortisol responses.

CONCLUSIONS: Our results suggest that relatively low prenatal and postnatal blood lead levels--notably those below the 10 [micro]g/dL blood lead level identified by the Centers for Disease Control and Prevention for public health purposes--can alter children's adrenocortical responses to acute stress. The behavioral and health consequences of this Pb-induced HPA dysregulation in children have yet to be determined.

KEY WORDS: adrenocortical, children, cortisol, HPA axis, lead, metal pollution, Pb, stress. Environ Health Perspect 116:249-255 (2008). doi:10.1289/ehp.10391 available via http://dx.doi.org/[Online 17 November 2007]

**********

Recent research has evaluated the effects of lead exposure on responses of the hypothalamic-pituitary-adrenal (HPA) axis to acute stress. These responses have been considered in animals, through assessment of glucocorticoid blood levels before and after the onset of an acute stressor. Several studies (Cory-Slechta et al. 2004; Virgolini et al. 1999, 2004) have demonstrated a significant positive association in rats between Pb exposure and baseline plasma corticosterone (the glucocorticoid equivalent of cortisol in humans). In addition, many studies have shown that greater Pb exposure is associated with heightened corticosterone reactivity to acute stress [Baos et al. 2006; Cory-Slechta et al. 2004; Virgolini et al. 2004 (in rats)]; however, in some cases, Pb exposure is associated with either a diminished glucocoticoid response to acute stress [Levesque et al. 2003 (in yellow perch); Virgolini et al. 2004 (in rats)] or no significant effect on acute stress reactivity (Virgolini et al. 2004). To our knowledge, the HPA response to acute stress as a function of Pb exposure has not been evaluated in humans. In the present study we consider salivary cortisol response to acute stress, in children with low-level Pb exposure.

Several studies have considered factors that affect children's adrenocortical responses to acute stress. Such research has generally focused either on intrinsic differences such as temperament (van Bakel and Riksen-Walraven 2004) and attachment (Gunnar et al. 1989) or social contextual factors such as parental maltreatment (Cicchetti and Rogosch 2001) and abuse (De Bellis et al. 1994). Although exposure to environmental toxicants may co-vary with these variables (e.g., Gump et al. 2007), the study of toxicant effects is relatively novel to developmental psychobiology. Similarly, the study of acute stress responses in children is novel in neurotoxicology. Notably, however, we recently reported a positive association between blood Pb and cardiovascular reactivity to acute stress in children (Gump et al. 2005). Here we consider the further association of blood Pb to adrenocortical reactivity to acute stress in these children.

Pb-induced increases in HPA reactivity in children are likely to have far-reaching consequences.

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
Loading One moment ...
Project items
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited article

Low-Level Prenatal and Postnatal Blood Lead Exposure and Adrenocortical Responses to Acute Stress in Children
Settings

Settings

Typeface
Text size Smaller Larger
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

While we understand printed pages are helpful to our users, this limitation is necessary to help protect our publishers' copyrighted material and prevent its unlawful distribution. We are sorry for any inconvenience.
Full screen

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.

Are you sure you want to delete this highlight?