title: Hypothalamic-pituitary-adrenal axis suppression in asthmatic school children.
abstract: OBJECTIVE
  Hypothalamic-pituitary-adrenal axis suppression (HPAS) when treating children with corticosteroids is thought to be rare. Our objective was to determine the prevalence of and predictive factors for various degrees of HPAS.
  
  
  METHODS
  Clinical features of HPAS, doses, adherence, asthma score, and lung functions were recorded in 143 asthmatic children. The overnight metyrapone test was performed if morning cortisol was >83 nmol/L. Spearman correlations coefficients (r) were calculated between 3 postmetyrapone outcomes and each continuous variable. A multiple linear regression model of √postmetyrapone adrenocorticotropic hormone (ACTH) and a logistic regression model for HPAS were developed.
  
  
  RESULTS
  Hypocortisolemia was seen in 6.1% (1.8-10.5), hypothalamic-pituitary suppression (HPS) in 22.2% (14.5-29.9), adrenal suppression in 32.3% (23.7-40.9), HPAS in 16.3% (9.3-23.3), and any hypothalamic-pituitary-adrenal axis dysfunction in 65.1% (56.5-72.9). Log daily nasal steroid (NS) dose/m(2) was associated with HPAS in the logistic regression model (odds ratio = 3.7 [95% confidence interval: 1.1-13.6]). Daily inhaled corticosteroids (ICSs) + NS dose/m(2) predicted HPAS in the univariate logistic regression model (P = .038). Forced expiratory volume in 1 second/forced vital capacity <80% was associated with HPAS (odds ratio = 4.1 [95% confidence interval: 1.0-14.8]). Daily ICS + NS/m(2) dose was correlated with the postmetyrapone ACTH (r = -0.29, P < .001). BMI (P = .048) and percent adherence to ICS (P < .001) and NS (P = .002) were predictive of √postmetyrapone ACTH (R(2) = .176).
  
  
  CONCLUSIONS
  Two-thirds of children on corticosteroids may have hypothalamic-pituitary-adrenal axis dysfunction. In one-third, central function had recovered but adrenal suppression persisted. Predictive factors for HPAS are NS use, BMI, and adherence to ICS and NS.
authors.affiliation: Paediatric Endocrine Unit, Tygerberg Children’s Hospital, University of Stellenbosch, Cape Town, South Africa. zollner@sun.ac.za
authors.forename: Ekkehard Werner
authors.initials: EW
authors.lastname: Zöllner
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Lombard
authors.forename: Ushma
authors.initials: U
authors.lastname: Galal
authors.forename: F Stephen
authors.initials: FS
authors.lastname: Hough
authors.forename: Elvis M
authors.initials: EM
authors.lastname: Irusen
authors.forename: Eugene
authors.initials: E
authors.lastname: Weinberg
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000009:adverse effects*; D000309:Adrenal Insufficiency / Q000097:blood / Q000139:chemically induced*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D003350:Cortodoxone / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007018:Hypopituitarism / Q000097:blood / Q000139:chemically induced* / Q000453:epidemiology; D007027:Hypothalamic Diseases / Q000097:blood / Q000139:chemically induced* / Q000453:epidemiology; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D055118:Medication Adherence; D036501:Metered Dose Inhalers; D008797:Metyrapone; D010865:Pilot Projects; D010913:Pituitary-Adrenal System / Q000187:drug effects* / Q000503:physiopathology*; D011237:Predictive Value of Tests
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents; D000893:Anti-Inflammatory Agents; D000324:Adrenocorticotropic Hormone; D003350:Cortodoxone; D006854:Hydrocortisone; D008797:Metyrapone