About 1 in 4 patients with difficult-to-control type 2 diabetes have hypercortisolism — and two separate studies now agree. Data from the CAPTAIN-T2D trial, presented at ENDO 2026, closely mirror findings from the earlier CATALYST trial, suggesting elevated cortisol may be a hidden driver of uncontrolled diabetes and cardiovascular risk. Experts say it's time to routinely screen for cortisol dysfunction in this patient population.
Two independent studies are now pointing to the same surprising finding: roughly 1 in 4 patients with difficult-to-control type 2 diabetes (T2D) have hypercortisolism — a condition where the body produces too much cortisol. Interim results from the CAPTAIN-T2D trial, presented at ENDO 2026, found that 25.4% of patients had elevated morning cortisol levels after a dexamethasone suppression test, nearly identical to the 23.8% seen in the earlier CATALYST trial.
The consistency across both studies is significant. Elevated cortisol levels — even below the threshold for classic Cushing's syndrome — have been linked to higher rates of cardiovascular disease and may help explain why some patients' diabetes and hypertension remain stubbornly uncontrolled despite multiple medications. A separate Harvard-led study also presented at ENDO 2026 found that ACTH-independent hypercortisolism was most prevalent in patients with both T2D and obesity (10.2%), reinforcing the cardiometabolic connection.
Key Takeaways:
Why it matters: These findings challenge the traditional view of T2D as a straightforward metabolic condition, suggesting cortisol dysregulation may be an underrecognized contributor. Routine cortisol screening in uncontrolled T2D patients could open the door to more targeted, personalized treatment strategies.
