Twenty-nine ESRD patients with sustained hypotension were investigated for possible AI. Salivary cortisol was assessed at baseline and 30 min after 25 μg ACTH i.m. (LDTs). The dosage of salivary aldosterone was performed in salivary cortisol hypo-responders. Basal blood samples were drawn for steroids, renin and ACTH measurements.
A clear separation between patients with normal and impaired adrenal function was obtained through salivary cortisol levels at 30 min after ACTH. AI was detected in six cases (21%) through impaired salivary cortisol responses; stimulated salivary aldosterone helped to differentiate primary (n = 3) from secondary AI (n = 3). ROC curves showed that cutoff values for basal SAF ≤4.4 nM and serum cortisol ≤232.0 nM suggest AI (sensitivities: 93%and 69%; specificities: 86.4%and 91%, respectively).
We conclude that ACTH stimulated SAF is an accurate biomarker for the diagnosis of AI in hypotensive ESRD patients. Neither basal salivary cortisol nor serum cortisol showed 100%sensitivities for the detection of AI.