Endocrine Abstracts

Abstract: The secondary adrenal insufficiency (SAI) is life-threatening disease. 30–50% of patients have SAI following craniospinal irradiation (CSI). The “gold standard” of SAI diagnosis is the insulin tolerance test but it is demanding for patient and medical staff. The simple and reliable test would allow to use ITT rarely. The aim was to evaluate probability of using DHEA-S in SAI diagnosis. 41 patient after CSI non-pituitary brain tumors survivor and 23 healthy were included. The mean age was 20.5±3,6 years (16–30), follow-up was more than 2 years. Cortisol, DHEA-S, ACTH were determinate and then ITT was performed. The patients were divided into SAI-group and without SAI (W-SAI) after ITT.

Results: 18/41 had SAI by ITT. DHEA-S was significantly lower in SAE-group 2.65±1.4 μmol/l than in W-SAI and healthy (5.2±2.1 and 7.6±4.4 μmol/l, P=0.001). Cortisol in SAI and healthy was the same (326±99.4 and 390.5±161 mmol/l, P=0.2) but lower that W-SAI (495.2±186 mmol/l, P=0.05). ACTH was not differ. DHEA-S/cortisol ratio was lower in SAI (P=0.002), ACTH/cortisol was the same. There was the significant correlation between SAI and cortisol (r=0.57, P=0.02) and SAI and cortisol (r=0.49, P=0.02). There was not correlation between age and DHEA-S. DHEA-S did not have gender difference within SAI and W-SAI. AUC cortisol was 0.79; AUC DHEA-S 0.9; AUC DHEA-S/cortisol 0.67. All patients who had basal cortisol lower than 200 nmol/l or DHEA-S lower than 2.0 μmol/l were in SAI-group, and who had cortisol or DHEA-S more than 500 and 3.7 respectively did not have SAI by ITT. Cut-off DHEA as 3.7 had Se 73% and SP 100%. When linear regression has applied, AUC cortisol+DHEA-S was 0.96.

Conclusion: DHEA-S had higher sensitive and specificity that cortisol for diagnosis of SAI in patients younger than 30 years following craniospinal irradiation. DHEA-S can used without gender accounting in this group. Combined examination by DHEA-S and cortisol is optimal.