Could Hidden Cortisol Be Why Your Diabetes or Blood Pressure Won’t Improve?

At ENDO 2026, Dr. Richard Auchus of the University of Michigan shares his perspectives on the connection between type 2 diabetes and hard-to-control hypertension and high cortisol in Corcept Therapeutics’ landmark studies. The interview covers two related studies investigating how often “common” diseases—difficult-to-control diabetes and hypertension are actually being driven by undiagnosed adrenal dysfunction, particularly mild, clinically significant cortisol excess from adrenal adenomas.

CATALYST Study found that about a quarter of patients failed the test (cortisol did not suppress below 1.8 µg/dL), despite efforts to exclude common causes of false positives. Dr. Auchus noted this prevalence echoes findings from French and Brazilian studies dating back to the late 1990s, which had previously been dismissed as reflecting “special populations.” Patients who failed the DST were randomized to mifepristone (a cortisol receptor antagonist) versus placebo. The placebo group showed no improvement (or slight worsening), while the mifepristone group saw HbA1c drop by approximately 1.4% — a magnitude significant enough to support drug approval for diabetes treatment on its own.

The MOMENTUM Study was done in a population of people with poorly controlled hypertension despite multiple medications.  It tested for primary aldosteronism (per existing guidelines) and the 1mg DST, and found a similar prevalence of abnormal DST results as seen in CATALYST.

Dr. Auchus tells us he wasn’t surprised by the prevalence of abnormal test results (given prior literature), but was surprised by the magnitude of glycemic improvement with mifepristone. He stresses that Cortisol (and aldosterone, for hypertension) should be on the differential whenever diabetes or hypertension is unexpectedly difficult to control. Broad implementation of treatment isn’t ready yet. This remains a research question, with the next challenge being how to “sort out the different flavors” of patients identified through screening and tailor treatment accordingly.

Note: The DST (Dexamethasone Suppression Test) is a diagnostic tool used to measure how well the body’s hormone feedback system is working, specifically to evaluate if the body is producing too much cortisol.