Santral Adrenal Yetmezlik Tanısında Tükürük Kortizol Ölçümünün Geliştirilmesi ve Serum DHEA ile DHEA-S Düzeylerinin Rolünün Tayini

Abstract

The accurate and early diagnosis of central adrenal insufficiency (AI) is important. Saliva has become an important diagnostic tool in recent years due to its many advantages. Valid, applicable and sensitive LC-MS/MS method has gained importance in recent years for the determination of steroids in plasma and urine. In this study, we describe an accurate and selective method for the measurement of cortisol by LC-MS/MS in saliva samples collected from children with suspected central adrenal insufficiency who underwent low-dose ACTH stimulation test; it was then analytically validated. Peak values of salivary cortisol were obtained at 40 min after simulation.. Linear regression analysis showed was strong correlation between salivary cortisol and serum cortisol in response to LDT (r=0,865). Using ROC analysis, the cut-off value for serum cortisol was taken as 550 nmol/L, and the cut-off values for salivary cortisol were determined as 12.0 nmol/L and 12.0 nmol/L at 40 minutes and at peak values, respectively. Additionally, analytical performance of saliva cortisol assay by LC- MS/MS method was found to suitable. Therefore, based on the baseline salivary cortisol concentration of 4.6 nmol/L in the central AI group, we proposed a new algorithm as a rapid and cost-effective method in routine practice. This study also showed that plasma DHEA and DHEAS levels were significantly low in the central AI group than that of control group (p <0,001). In conclusion, the peak salivary cortisol of 12 nmol/L as a cutoff value can be used for the diagnosis of central AI. The sensitive and selective mass spectrometric salivary cortisol and plasma DHEA-S measurements, may be an alternative approach to assess HPA axis.