Hospitalization and sickness are known as possible interference factors on the neuroendocrine (pituitary-adrenal) response to stimulation tests. To evaluate this response, we studied 11 hospitalized children (mean age: 5.4 ± 3.3 years). The stimuluation test using ovine corticotropin-releasing hormone (CRH; 1 ±g/kg) was performed at 8:00 am. Blood samples were collected at 0, 30, 60, and 90 min after CRH injection, to measure ACTH and cortisol. No adverse effect related to the use of CRH was observed. Basal levels of ACTH and cortisol were high in 3 and 4 children, respectively, probably reflecting the response of HPA axis to stress. The mean basal level of ACTH was 9.9 ± 8.0 pmol/l and its mean maximum concentration was 15.1 ± 11.9 pmol/l (p>0.05). There was no significant difference between the basal and maximun levels. The mean basal level of cortisol was 725.6 ± 264.9 nmol/dl and its mean maximum concentration was significantly higher: 1095.3 ± 479.9 nmol/dl (p<0.05). ACTH peak level preceeded the cortisol peak level. Thus, a large interindividual variation was observed, suggesting that the interference of individual factors and those related to the procedure should be considered in the correct interpretation of the results for the CRH stimulation test.
CRH; Pituitary-adrenal axis; Stress; Hospitalization
