Value of plasma ACTH and serum cortisol in diagnosis of adrenal failure

The levels of plasma ACTH and serum cortisol were determined in 13 patients with primary adrenal failure （PAF）, 31 patients with secondary adrenal failure （SAF） and 42 normal people. The levels of plasma ACTH were significantly higher in patients with PAF and apparently lower in patients with SAF than those in the normal people. No overlaping was found in the ACTH level between the patients with PAF and the normal people but an overlaping rate of 83.9% in the ACTH level between the patients with SAF and the normal people was noticed. The level of serum cortisol were significantly decreased in the patients with PAF or SAF as compaired with those in the normal people and showed a few overlaping （13.6%） between the patients with PAF or SAF and the normal people. An aminoglutethemide （AG） test was done in 14 patients with SAF, 3 patients with PAF and 13 normal people. The overlaping of plasma ACTH between the patients with SAF and the normal people diappeared following the AG administrations. Our study suggests that （1） serum cortisol is useful in the establishment of adrenal failure but could not make a clear distinction between PAF and SAF; and （2） plasma ACTH could differentiate PAF from SAF; and （3） AG test could differentiate SAF from normal conditions.