RF09 | PSAT83 Diagnosis of Adrenal Insufficiency Based on Peak Stimulated Cortisol Levels Between 14 and 18 mcg/dL on High Dose Cosyntropin Stimulation Testing

BACKGROUND: Traditionally, stimulated serum cortisol < 18 mcg/dL at 30 or 60 minutes has been used as the cutoff for diagnosis of adrenal insufficiency (AI) during high dose cosyntropin stimulation testing (CST). Recent studies suggest that a cutoff of 14-15 mcg/dL is more accurate when using more specific monoclonal immunoassays (IAs). In February 2017, our institution switched from a polyclonal IA to a monoclonal IA. Despite this change, providers were diagnosing AI based on the 18 mcg/dL cutoff. Long term glucocorticoid use has several unwanted pleiotropic effects such as impaired glucose tolerance or diabetes mellitus (DM), hypertension (HTN), and increased risk of infection. Our study aims to evaluate patients with peak stimulated cortisol levels between 14-18 mcg/dL diagnosed with AI and placed on steroids. METHODS: We retrospectively reviewed charts of patients with peak cortisol levels 14-18 mcg/dL at 30 or 60 minutes on high dose CST with 250 mcg cosyntropin between February 2017 and August 2021. Cortisol levels were assessed using the monoclonal IA Roche Elecsys Cortisol II. Data regarding type and etiology of AI as well as patient demographics, comorbidities, steroid regimen, and follow up cortisol testing was collected. Worsening HTN and DM were defined as increase in blood pressure and HgbA1c respectively and/or intensification of medications between baseline at time of CST and last follow up while on steroids. RESULTS: 41 patients met inclusion criteria. 29 (71%) patients were female and mean age at CST was 52 years (range 21-86). Most patients were diagnosed with secondary (71%) or partial secondary (19%) AI by provider. Most common etiologies were pituitary disease (45%), chronic steroid use (24%), and unilateral adrenalectomy (19%). Mean follow up was 23 months (range 0.5-57). 33 (80%) patients were started or continued on glucocorticoid replacement. Remaining patients who were never started on steroids had a peak cortisol ≥ 15.6 mcg/dL. 21/33 (64%) of patients started on steroids had repeat adrenal function testing a mean of 18 months (range 2-42) after the initial CST. Based on testing or clinical judgement, 19/33 (58%) were taken off steroids. In patients treated with steroids, 64% developed weight gain, 42% worsening HTN, and 6% worsening DM. Additionally, 48% developed an infection, 24% insomnia, and 15% psychiatric illness. CONCLUSIONS: The majority of patients with peak stimulated cortisol between 14-18 mcg/dL on high dose CST had secondary AI. Over 50% of patients started on steroids were later able to stop. Steroid-related complications were observed, but this may not differ significantly from the general population. This study underscores the importance of interpreting CST results in the context of the cortisol assay used and evaluating patients with secondary AI for recovery of the hypothalamic-pituitary-adrenal axis. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m., Saturday, June 11, 2022 1:06 p.m. - 1:11 p.m.