Growth hormone deficiency and central adrenal insufficiency in adult survivors of youth brain tumors

• Published in: Experimental and Clinical Endocrinology & Diabetes
• Main Authors: Tselovalnikova, TY, Yudina, AE, Pavlova, MG, Zilov, AV, Mazerkina, NA
• Format: Conference Proceeding
• Language: English
• Published: 07.03.2013
• ISSN: 0947-7349; 1439-3646
• DOI: 10.1055/s-0033-1336683

Aim: With improved management of brain tumors in youth, there are more survivors with long-term sequelae of radiation and chemotherapy. The aim of this study was to determine the prevalence of growth hormone (GH) deficiency (GHD) and central adrenal insufficiency (CAI) in adult survivors of youth brain tumors. Methods: Insulin-like growth factor-1 (IGF-1), basal GH and plasma cortisol, 24-h urinary cortisol, insulin tolerance test (ITT) were performed in 13 patients (7 men, 6 women) after treatment for non-pituitary brain tumors. Patients received craniospinal irradiation (CSI) 35 Gy, boost to the tumor up to 55 Gy, and chemotherapy. The median age of observed patients was 20 [18;23], age at original diagnosis – 13 [10;14], median follow-up was 3 years [2;6]. Peak of cortisol in ITT< 550 nmol/l was rated as CAI. Severe GHD was diagnosed if the value of peak GH in ITT< 3 ng/ml. Results: Median of target height was 174 [165;176.5]. 9 patients were attained target height. 1 patient had been previously diagnosed with GHD, he received GH-replacement therapy for 6 years, but in spite of therapy his final growth was 157 cm and his target height was 185 cm +/-10 cm. In 11 patients there were no significant peaks of GH in ITT – median level – 1.2 ng/ml [0.37;1.85], which was rated as severe GHD. Median level of 24-h urinary cortisol was 74.5 nmol [60.6;170.5], cortisol below the lower value was in 3 of 13 patients. On testing by the ITT median of cortisol on the peak of hypoglycemia was 576 nmol/l [363;648]. CAI was diagnosed in 6 patients. Conclusions: The prevalence of GHD and CAI after CSI are extremely high – 85% and 46% respectively. Simple measurement of cortisol in a single blood sample, 24-h urinary cortisol useless for detecting CAI. Requires ITT for deciding on the timely appointment of replacement therapy.