Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Although the effect of inhaled corticosteroids (ICS) on the hypothalamic- pituitary-adrenal
axis (HPA) has been regarded as a “benign physiological response”, a survey published in
2002 suggested that adrenal crisis is more common in asthmatic children on ICS than
previously thought. Relying on clinical features to detect chronic adrenal insufficiency
secondary to corticosteroids may not be wise, as these are non-specific and can therefore
easily be missed. Accurate biochemical assessment of the whole axis to detect subclinical
HPA suppression (HPAS) is thus desirable. A review of the literature indicates that basal
adrenal function tests, including plasma cortisol profiles, do not identify which children can
appropriately respond to stress. There is no evidence to suggest that the degree of the
physiological adjustment of the HPA to ICS and/or nasal steroids (by reducing basal cortisol
production), predicts HPAS. Cortisol profiles should therefore only be used to demonstrate
differences in systemic activity of various ICS and delivery devices. Only two tests,
considered as gold standard adrenal function tests [the insulin tolerance test (ITT) and the
metyrapone test] can assess the integrity of the whole axis. / AFRIKAANSE OPSOMMING: Die outeurs van ´n opname wat in 2002 gepubliseer is stel voor dat ´n bynierkrisis meer
algemeen by asmatiese kinders, wat inhalasie kortikosteroïede ontvang, voorkom as wat
voorheen gedink is. Dit is strydig met die gevestigde opvatting dat die effek van IKS op die
hipotalamiese-hipofise-bynier-as (HHB) ’n “goedaardige fisiologiese reaksie” is. Die kliniese
kenmerke van kroniese bynierontoereikendheid sekondêr tot die gebruik van kortikosteroïede
(KS) is nie-spesifiek en gevolglik onbetroubaar. ´n Akkurate biochemiese toets van
subkliniese HBB onderdrukking (HHBO) sou gevolglik waardevol wees. ´n Literatuur oorsig
toon dat toetse van basale bynierfunksie, insluitend plasma kortisol (K) profiele, nie kinders
uitken wat toepaslik op stres sal reageer nie. Daar is geen bewyse dat die graad van
fisiologiese aanpassing van die HHB, soos aangedui deur laer K-vlakke, na die gebruik van
IKS en/of nasale steroïede (NS), HHBO voorspel nie. Serum K profiele is dus slegs van
waarde om die sistemiese aktiwiteit van verskillende IKS en toedieningsstelsels te ondersoek.
Slegs twee toetse, naamlik die insulien toleransie toets (ITT) en die metyrapone -(MTP)-toets
(wat beide as die goue standaard van bynier funksie beskou word), kan die integriteit van die
hele as meet.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019/11052 |
| Date | 12 1900 |
| Creators | Zollner, Ekkehard Werner Arthur |
| Contributors | Hough, F. S., Irusen, E. M., Stellenbosch University. Faculty of Medicine and Health Sciences. Department of Paediatrics and Child Health. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Format | 101 pages |
| Rights | Stellenbosch University |
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