A single test is not enough. The cortisol story unfolds over years.
For decades, a single hormone test has shaped how physicians understand and manage benign adrenal tumors — a quiet assumption embedded in clinical routine. A landmark seven-year study of more than 2,500 patients across 14 countries now reveals that cortisol levels in these tumors are far less stable than medicine has presumed, and that the patients whose levels remain persistently elevated carry a measurably heavier burden on their hearts. The findings remind us that chronic disease is not a photograph but a film, and that the stories our bodies tell require repeated listening.
- Cortisol secretion status shifted in nearly one in four patients over time, exposing a critical blind spot in the standard practice of relying on a single diagnostic test at the moment of diagnosis.
- Patients with persistently elevated cortisol faced a 34% higher rate of worsening hypertension, losing an average of two years of well-controlled blood pressure compared to those with normal levels.
- The compounding cardiometabolic burden — spanning obesity, high blood pressure, diabetes, and high cholesterol — significantly raises these patients' lifetime risk of heart attack, stroke, and heart failure.
- Researchers and clinicians are now pressing for updated guidelines that mandate repeated hormonal testing, arguing that current protocols leave high-risk patients undetected and undermanaged.
- Surgery to remove the adrenal tumor is emerging as a viable intervention for selected patients, with recent trial data suggesting it can meaningfully improve blood pressure control in those most at risk.
For years, a single hormone test at diagnosis has been the cornerstone of managing benign adrenal tumors — a clinical shorthand that assumed cortisol levels, once measured, would remain stable. A major study published in The Lancet Diabetes & Endocrinology this week dismantles that assumption with striking force.
Tracking 2,525 patients across 25 specialist centers in 14 countries over nearly seven years, researchers from the European Network for the Study of Adrenal Tumors found that cortisol status changed in 22% of patients — far more often than previously recognized, and most often within the first three years after diagnosis. The hormone that regulates metabolism, blood pressure, and immune function was, in many patients, quietly shifting beyond the reach of a single clinical snapshot.
The consequences proved most serious for those whose cortisol remained persistently elevated. These patients experienced a 34% higher rate of worsening hypertension and lost an average of two years of well-controlled, hypertension-free time over a decade — a gap that compounds meaningfully across a lifetime. Their overall cardiometabolic burden, encompassing obesity, high blood pressure, diabetes, and high cholesterol, was significantly heavier, predisposing them to heart failure, heart attack, and stroke.
Professor Alessandro Prete of the University of Birmingham, the study's corresponding author, called for these patients to be recognized as a distinct, higher-risk group requiring closer monitoring and proactive management of modifiable risk factors. The findings also align with emerging trial evidence that surgical removal of the adrenal tumor can improve blood pressure control in selected cases, offering a concrete intervention for those most vulnerable.
The study leaves clinicians with an urgent question: how often should cortisol testing be repeated? Current guidelines reserve retesting for specific circumstances, but the authors argue that prospective research is needed to determine whether routine reassessment could meaningfully sharpen risk stratification. The broader lesson is both clinical and philosophical — the cortisol story unfolds over years, and a medicine that listens only once may miss the most important chapters.
For years, doctors treating patients with benign adrenal tumors have relied on a single hormone test to understand their cortisol status and predict their long-term health. A major study published this week in The Lancet Diabetes & Endocrinology upends that assumption. Researchers tracking 2,525 patients across 25 specialist centers in 14 countries found that cortisol levels are far more volatile than anyone expected—and that instability carries real consequences for the heart.
Cortisol, the steroid hormone produced by the adrenal glands, regulates metabolism, blood pressure, and immune function. When benign tumors form on these glands—a condition found incidentally in 3 to 7 percent of adults—the body can begin producing cortisol on its own, independent of the brain's normal control mechanisms. This condition, called mild autonomous cortisol secretion or MACS, has long been assumed to be stable. A single test at diagnosis, doctors thought, would tell them everything they needed to know about a patient's risk.
The new study, conducted over nearly seven years by researchers from the European Network for the Study of Adrenal Tumors, challenges that assumption directly. Using the standard 1-milligram overnight dexamethasone suppression test—the clinical benchmark for detecting autonomous cortisol production—the team repeatedly tested each patient to track how their hormone levels changed over time. What they found was striking: cortisol status shifted in 22 percent of patients, far more often than previously recognized. Most of these changes happened within the first three years after diagnosis, suggesting that a snapshot in time is insufficient to characterize a patient's true cortisol profile.
But the study's most clinically important finding concerns those whose cortisol remained persistently elevated. These patients faced a 34 percent higher rate of worsening high blood pressure compared to those whose cortisol stayed normal. Over a decade, patients with persistent MACS lost an average of two years of well-controlled, hypertension-free time—a difference that compounds across a lifetime. The broader picture is equally sobering: persistent cortisol elevation increased the overall cardiometabolic burden, a measure that captures the combined weight of obesity, high blood pressure, type 2 diabetes, and high cholesterol. That burden predisposes patients to serious, chronic diseases including heart failure, heart attack, and stroke.
Professor Alessandro Prete, a clinical associate professor of endocrinology at the University of Birmingham and the study's corresponding author, emphasized the practical implications. The findings suggest that patients with persistently abnormal cortisol levels constitute a distinct, higher-risk group who warrant closer monitoring and more aggressive management of modifiable risk factors—blood pressure, cholesterol, weight, and smoking status. The study also aligns with recent randomized trial data showing that surgery to remove the adrenal tumor can improve blood pressure control in MACS patients, offering a potential intervention for those at greatest risk.
The research raises a fundamental question about clinical practice: how often should cortisol testing be repeated in patients with benign adrenal tumors? Current guidelines recommend retesting only in specific clinical circumstances, but the authors argue that prospective studies are needed to determine whether repeated hormonal assessment could meaningfully improve risk stratification beyond established cardiovascular risk factors. For now, the message is clear: a single test is not enough. The cortisol story, it turns out, unfolds over years, and missing that narrative could cost patients their cardiovascular health.
Notable Quotes
A single hormone test at diagnosis tells us everything we need to know about a patient's cortisol status—this study shows that is simply not the case.— Professor Alessandro Prete, University of Birmingham, study corresponding author
The Hearth Conversation Another angle on the story
Why does it matter that cortisol levels change over time? Couldn't doctors just treat based on what they find at diagnosis?
Because the trajectory matters as much as the snapshot. A patient whose cortisol normalizes on its own faces a very different future than one whose cortisol stays elevated. The second group loses years of good blood pressure control—that's not abstract, that's real cardiovascular damage accumulating.
So you're saying 22 percent of patients are being misclassified by a single test?
Not misclassified exactly, but incompletely characterized. A test that says "normal" today might not predict what happens in year three. And if you're in that 22 percent whose status changes, you might not get the monitoring you actually need.
What does persistent elevation actually do to the body?
It's like a slow burn on your cardiovascular system. The cortisol keeps your blood pressure elevated, keeps your metabolism dysregulated, keeps your body in a state of chronic stress. Over ten years, that adds up to two lost years of stable blood pressure—and that's just one measure. The heart attack and stroke risk is real.
If surgery can help, why isn't it offered to everyone with MACS?
Because not everyone with MACS is at the same risk. The study identifies persistent elevation as the key marker—that's the group where surgery makes sense. But you have to know who that group is, and you can't know that from a single test.
So what changes in practice?
Doctors need to retest. They need to follow these patients over time, not assume stability. And they need to be more aggressive about managing blood pressure and other risk factors in the ones whose cortisol stays high. It's a shift from passive monitoring to active intervention.