title: Hair cortisol as a hypothalamic-pituitary-adrenal axis biomarker in pregnant women with asthma: a retrospective observational study.
abstract: Cortisol is a hormone involved in many physiological functions including fetal maturation and epigenetic programming during pregnancy. This study aimed to use hair cortisol as a biomarker of chronic inhaled corticosteroid (ICS) exposure and assess the potential effects of asthma on the hypothalamic-pituitary-adrenal (HPA) axis in pregnant women. We hypothesized that pregnant women with asthma treated with ICS would exhibit lower hair cortisol concentrations, indicative of adrenal suppression, compared to women with asthma not using ICS and women who do not have asthma.
  
  
  
  We performed an observational retrospective cohort study. Hair samples were analyzed from pregnant women with asthma, with (n = 56) and without (n = 31) ICS treatment, and pregnant women without asthma (n = 31). Hair samples were segmented based on the growth rate of 1 cm/month and analyzed by enzyme immunoassay to provide cortisol concentrations corresponding to preconception, trimesters 1-3, and postpartum. Hair cortisol concentrations were compared within and among the groups using non-parametric statistical tests.
  
  
  
  Hair cortisol concentrations increased across trimesters for all three groups, but this increase was dampened in women with asthma (P = 0.03 for Controls vs. ICS Treated and Controls vs. No ICS). ICS Treated women taking more than five doses per week had hair cortisol concentrations 47 % lower in third trimester than Controls. Linear regression of the third trimester hair cortisol results identified asthma as a significant factor when comparing consistent ICS use or asthma as the predictor (F(1, 25) = 9.7, P = 0.005, R(2) adj = 0.257).
  
  
  
  Hair cortisol successfully showed the expected change in cortisol over the course of pregnancy and may be a useful biomarker of HPA axis function in pregnant women with asthma. The potential impact of decreased maternal cortisol in women with asthma on perinatal outcomes remains to be determined.
authors.affiliation: Division of Clinical Pharmacology and Toxicology, The Hospital for Sick Children, Toronto, ON, Canada.|Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.
authors.forename: Laura
authors.initials: L
authors.lastname: Smy
authors.affiliation: Child & Family Research Institute, Vancouver, BC, Canada.|Division of Translational Therapeutics, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Kaitlyn
authors.initials: K
authors.lastname: Shaw
authors.affiliation: Child & Family Research Institute, Vancouver, BC, Canada.|Division of Translational Therapeutics, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.|University Institute of Clinical Chemistry, Inselspital Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Ursula
authors.initials: U
authors.lastname: Amstutz
authors.affiliation: Child & Family Research Institute, Vancouver, BC, Canada.|Division of Translational Therapeutics, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Smith
authors.affiliation: Department of Obstetrics & Gynecology, St. Michael's Hospital, Toronto, ON, Canada.
authors.forename: Howard
authors.initials: H
authors.lastname: Berger
authors.affiliation: Child & Family Research Institute, Vancouver, BC, Canada. bcarleton@popi.ubc.ca.|Division of Translational Therapeutics, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada. bcarleton@popi.ubc.ca.|Pharmaceutical Outcomes Programme, Child & Family Research Institute, 950 W 28th Avenue, Vancouver, BC, V5Z 4H4, Canada. bcarleton@popi.ubc.ca.
authors.forename: Bruce
authors.initials: B
authors.lastname: Carleton
authors.affiliation: Division of Clinical Pharmacology and Toxicology, The Hospital for Sick Children, Toronto, ON, Canada.|Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.
authors.forename: Gideon
authors.initials: G
authors.lastname: Koren
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000494:pharmacology* / Q000627:therapeutic use; D000311:Adrenal Glands / Q000187:drug effects*; D000328:Adult; D001249:Asthma / Q000188:drug therapy; D015415:Biomarkers / Q000032:analysis; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000378:metabolism; D010913:Pituitary-Adrenal System / Q000187:drug effects* / Q000378:metabolism; D049590:Postpartum Period; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy; D011263:Pregnancy Trimester, Third / Q000378:metabolism
chemical_list: D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D006854:Hydrocortisone
keywords: Adrenal suppression; Asthma; Biomarker; HPA axis; Hair cortisol; Pregnancy