Abstract
Hypothalamo-pituitary-adrenal (HPA) axis dysfunction is a potentially life-threatening condition. It is of paramount importance that safe, reliable diagnostic tests be available to identify patients at risk for adrenal insufficiency. The 250μg Adrenocorticotropic hormone (ACTH) stimulation test is commonly used to assess adrenocortical function. The 250μg dose is supraphysiological, therefore several investigators, over the years, have used 1μg ACTH stimulation test to assess adrenocortical function.The aim of the study was to compare the response of healthy adult Nigerian subjects to the 250μg and 1μg ACTH tests.Ten healthy subjects, five males and five females, aged between 20-60 years, (mean, 38.7 years) participated in this study. They all had normal medical histories and physical examinations, were nonsmokers, and had never received any type of glucocorticoid therapy. Serum chemistries, full blood counts, erythrocyte sedimentation rate, were all within normal limits. Both low dose ACTH test and standard dose ACTH test were performed on the 10 subjects in a randomized order on different days.There was no statistically significant difference in mean serum cortisol levels between the two test doses at 30 minutes (928.4 vs 929.8nmol/L). There was a strong correlation between 30-minute cortisol responses to 1μg and 250μg ACTH stimulation tests, r=0.999; p<0.001.In agreement with other published data, our study confirms that 1μg ACTH stimulates adrenocortical secretion in normal subjects in the period 30 minutes post injection comparable to 250μg ACTH testing.
Keywords: Cortisol; adrenocorticotropic hormone (ACTH); hypothalamo-pituitary-adrenal (HPA); low dose ACTH Nigerians.
Résumé
Le dysfonctionnement de l’axe hypothalamo hypophyseale est potentiellement une condition dangereuse pour la vie. Il est d’une importance capital que les diagnostiques tests justes et fiables soient disponibles pour identifier les patients a risque d’insuffisance adrenale. Le test de stimulation de l’hormone adrenocorticotropique est généralement utilisé pour déterminer les fonctions adrenocorticales. La dose de250μg est supra physiologique, cependant plusieurs investigateurs, pendant des années, ont utilises la dose de1μg d’ACTH pour déterminer la fonction adrenocorticale. Le but de l’étude était de comparer la réaction des sujets Nigérians adultes et bien portent aux tests de 250 μg et 1 μg ACTH. Dix sujets bien portants, cinq males et cinq femelles âgés entre 20-60 ans,(moyenne, 38.7 ans) ont participe a cette étude, ils avaient tous un passé médical normal et des examens physiques normales, ils étaient non fumeurs et n’avaient jamais reçu un quelconque type de thérapie glucocorticoïde. Le sérum chimique, le taux de sang, le taux de sédimentation de l’érythrocyte étaient tous dans les limites normales. La faible dose du test ACTH et la dose standard du test ACTH étaient faites sur les 10 sujets des jours différents. Il y’avait statistiquement pas de différence significative sur la moyenne du niveau de sérum cortisol entre les deux doses tests a 30 minutes (928.4 Vs 929.8 nmol/L). il y’avait une forte corrélation entre la réaction a 30 minutes de cortisol au test de stimulation ACTH 1 μg et 250 μg, R=0.999 ; p=0.001. En accord avec les données publies, notre étude confirme que 1 μg d’ACTH de sécrétion stimule d’adrenocorticale sur les sujets normaux dans une période de 30 minutes après l’injection est comparable a 250 μg d’ACTH testées.
Correspondence: Dr. I.A. Odeniyi, Department of Medicine, Lagos University Teaching Hospital, PMB 12003, Surulere, Lagos, Nigeria. E-mail: ifeode@yahoo.com
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